Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems, 54020-54047 [E8-21568]

Agencies

• National Highway Traffic Safety Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 73, Number 181 (Wednesday, September 17, 2008)]
[Proposed Rules]
[Pages 54020-54047]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-21568]



[[Page 54019]]

-----------------------------------------------------------------------

Part IV





Department of Transportation





-----------------------------------------------------------------------



National Highway Traffic Safety Administration



-----------------------------------------------------------------------



49 CFR Part 571



Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems; 
Proposed Rule

Federal Register / Vol. 73, No. 181 / Wednesday, September 17, 2008 / 
Proposed Rules

[[Page 54020]]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2008-0150]
RIN 2127-AK16


Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

AGENCY: National Highway Traffic Safety Administration, Department of 
Transportation (NHTSA).

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We are proposing to amend the Federal motor vehicle safety 
standard on motorcycle brake systems, in order to add and update 
requirements and test procedures and to harmonize with a global 
technical regulation for motorcycle brakes. If adopted, today's 
proposal would specify an additional dry brake test procedure to test 
each service brake control individually and with the motorcycle in the 
fully loaded condition, provide a new test procedure for assessing 
performance of motorcycle brakes from high speeds, provide a new wet 
brake test that better simulates in-service conditions, provide an 
improved test procedure for evaluating heat fade, add test procedures 
and performance requirements for antilock brake systems, if fitted, and 
add a power-assisted braking system failure test, if equipped.

DATES: Comment closing date: You should submit your comments early 
enough to ensure that Document Management receives them not later than 
November 17, 2008.

ADDRESSES: You may submit comments, identified by the docket number in 
the heading of this document, by any of the following methods:
     Federal eRulemaking Portal: Go to https://
www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: 1200 New Jersey Avenue, SE., West Building 
Ground Floor, Room W12-140, between 9 a.m. and 5 p.m. ET, Monday 
through Friday, except Federal holidays.
     Fax: 202-493-2251.
    Instructions: All submissions must include the agency name and 
docket number or Regulatory Identification Number (RIN) for this 
rulemaking. Note that all comments received will be posted without 
change to https://www.regulations.gov, including any personal 
information provided. Please see the discussion of the Privacy Act 
below. For detailed instructions on submitting comments and additional 
information on the rulemaking process, see the Public Participation 
heading of the Supplementary Information section of this document.
    Privacy Act: Anyone is able to search the electronic form of all 
comments received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78) or you may visit https://
DocketInfo.dot.gov.
    Docket: For access to the docket to read background documents or 
comments received, go to https://www.regulations.gov, or the street 
address listed above. Follow the online instructions for accessing the 
dockets.

FOR FURTHER INFORMATION CONTACT:
    For technical issues: Mr. George Soodoo, Division Chief, Vehicle 
Dynamics (NVS-122), Office of Crash Avoidance Standards (E-mail: 
george.soodoo@dot.gov) (Telephone: (202) 366-2720) (Fax: (202) 366-
5930) or Mr. Ezana Wondimneh, Division Chief, International Policy and 
Harmonization (NVS-133), Office of International Policy, Fuel Economy 
and Consumer Programs (E-mail: ezana.wondimneh@dot.gov) (Telephone: 
(202) 366-0846) (Fax: (202) 493-2290).
    For legal issues: Ms. Sarah Alves, Office of the Chief Counsel 
(NCC-112) (E-mail: sarah.alves@dot.gov) (Telephone: (202) 366-2992) 
(Fax: (202) 366-3820).
    You may send mail to these officials at National Highway Traffic 
Safety Administration, 1200 New Jersey Avenue, SE., Washington, DC 
20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Background
III. Current Requirements of FMVSS No. 122
IV. Harmonization Efforts
V. Proposed Improvements to FMVSS No. 122
    A. General
    1. New Terminology
    a. Motorcycle Categories
    b. Measurement of Deceleration and Stopping Distance
    2. Motorcycle Test Speed and Corrected Stopping Distance
    3. Test Method To Measure Peak Braking Coefficient
    4. Test Sequence
    5. Brake Application Force Measurement
    6. Brake Temperature Measurement
    7. Burnishing Procedure
    8. Notice of Wear
    B. Specific Performance Tests
    1. Dry Stop Test--Single Brake Control Actuated
    2. Dry Stop Test--All Service Brake Controls Actuated
    3. High-Speed Test
    4. Wet Brake Test
    5. Heat Fade Test
    6. Parking Brake System Test
    7. Antilock Brake System (ABS) Performance Test
    a. ABS Performance Test--Stopping Performance Requirement
    b. ABS Performance Test--Low-Friction to High-Friction Surface 
Transition Stop
    8. Partial Failure Test--Split Service Brake System
    9. Power-Assisted Braking System Failure Test
    C. Summary of Improvements
VI. Costs, Benefits, and the Proposed Compliance Date
VII. Differences Between the GTR and the NPRM
VIII. Regulatory Analyses and Notices
IX. Public Participation

I. Executive Summary

    Currently, motorcycle brake systems must comply with a series of 
performance requirements established in Federal Motor Vehicle Safety 
Standard (FMVSS) No. 122, Motorcycle Brake Systems, in the early 1970s. 
While the motorcycle brake performance requirements have ensured a 
minimum level of braking performance, they have not kept pace with the 
advancement of modern technologies. The National Highway Traffic Safety 
Administration (NHTSA) seeks to keep its standards up to date. This 
document proposes to update FMVSS No. 122 based on the Motorcycle Brake 
Systems Global Technical Regulation (GTR), which reflects the 
capabilities of current technologies. Updating the standard to reflect 
modern technologies would help prevent the introduction of unsafe 
motorcycle brake systems on the road. Moreover, benefits from 
harmonization including decreased testing costs and ease of market 
entry would accrue to current and new manufacturers, and would in turn 
get passed on to consumers. While there is not necessarily any 
quantifiable safety benefit for this proposal since virtually all 
motorcycles sold in the U.S. can currently meet the proposed 
requirements, the agency is planning on taking several other actions to 
decrease motorcycle fatalities.\1\
---------------------------------------------------------------------------

    \1\ See U.S. Department of Transportation, ``Action Plan to 
Reduce Motorcycle Fatalities,'' at 8 (October 2007), available at 
https://www.nhtsa.gov/motorcycles/index.cfm (hereinafter ``Action 
Plan to Reduce Motorcycle Fatalities''); National Highway Traffic 
Safety Administration (NHTSA), ``2006 Motorcycle Safety Program 
Plan,'' at 26 (2006), available at https://www.nhtsa.gov/portal/site/
nhtsa/menuitem.d7975d55e8abbe089ca8e410dba046a0/ (hereinafter ``2006 
Motorcycle Safety Program Plan'').

---------------------------------------------------------------------------

[[Page 54021]]

    The substantive performance tests and requirements of FMVSS No. 122 
have not been updated since their adoption in 1972. Since that time, 
motorcycle brake system technology has significantly changed and 
improved such that FMVSS No. 122 no longer reflects the current 
performance of motorcycle brake system technologies. In order to 
address modern braking technologies, the agency sought to improve the 
requirements and test procedures of FMVSS No. 122. These efforts 
coincided with the 2002 adoption of the initial Program of Work under 
the 1998 United Nations' Economic Commission for Europe (UNECE) 
Agreement Concerning the Establishment of Global and Technical 
Regulations for Wheeled Vehicles, Equipment and Parts Which Can Be 
Fitted And/or Be Used On Wheeled Vehicles (1998 Agreement).\2\ That 
program included motorcycle brake systems as one of the promising areas 
for the establishment of a GTR. The agency sought to work 
collaboratively on modernizing motorcycle brake regulations with other 
Contracting Parties to the 1998 Agreement (Contracting Parties), 
particularly Canada, the European Union and Japan. Through the exchange 
of information on ongoing research and testing and through the 
leveraging of resources for testing and evaluations, the agency 
participated in successful efforts that culminated in the establishment 
of the Motorcycle Brake Systems GTR under the 1998 Agreement. We 
believe that the provisions of the GTR would improve the current 
requirements and test procedures of FMVSS No. 122 by updating them to 
more closely reflect the capabilities of modern technologies.
---------------------------------------------------------------------------

    \2\ The 1998 UNECE Agreement Concerning the Establishment of 
Global and Technical Regulations for Wheeled Vehicles, Equipment and 
Parts Which Can Be Fitted And/or Be Used On Wheeled Vehicles (1998 
Agreement) was concluded under the auspices of the United Nations 
and provides for the establishment of globally harmonized vehicle 
regulations. This 1998 Agreement, whose conclusion was spearheaded 
by the United States, entered into force in 2000 and is administered 
by the UNECE's World Forum for the Harmonization of Vehicle 
Regulations (WP.29). See https://www.unece.org/trans/main/wp29/
wp29wgs/wp29gen/wp29age.html.
---------------------------------------------------------------------------

    The U.S., as a Contracting Party of the 1998 Agreement that voted 
in favor of establishing this GTR at the November 15, 2006 Session of 
the Executive Committee of the 1998 Agreement, is obligated under the 
Agreement to initiate the process for adopting the provisions of the 
GTR.\3\ This proposal is based on the Motorcycle Brake Systems GTR. If 
NHTSA decides to adopt amendments to FMVSS No. 122 that differ from the 
requirements of the GTR, the agency will first seek to amend the GTR by 
submitting a formal proposal to the Executive Committee of the 1998 
Agreement, in accordance with the Agreement.
---------------------------------------------------------------------------

    \3\ While the 1998 Agreement obligates such Contracting Parties 
to initiate rulemaking within one year of the establishment of the 
GTR, it leaves the ultimate decision of whether to adopt the GTR 
into their domestic law to the parties themselves.
---------------------------------------------------------------------------

    This proposal, if made final, would improve the current FMVSS No. 
122 requirements in several areas. First, it would make the dry brake 
test requirement more stringent by specifying testing of each service 
brake control individually, with the motorcycle in the fully loaded 
condition. Second, the proposal would establish a more stringent high 
speed test requirement by specifying a slightly higher rate of 
deceleration. Third, the proposal would replace the existing wet brake 
test with one that better simulates actual in-service conditions, by 
spraying water onto the brake disc, instead of submerging the brake 
system before testing. Fourth, the proposal would specify an improved 
heat fade test procedure based on European and Japanese national 
regulations, which share the same test procedure and performance 
requirements. Fifth, the proposal would specify performance 
requirements for antilock brake systems, if present. Finally, the 
proposal would establish a new test requirement to evaluate the 
motorcycle's performance in the event of a failure in the power-
assisted braking system, if so equipped.
    Besides updating requirements and test procedures to help ensure 
the safety of motorcycle brake systems, the proposal also provides 
benefits from harmonization. Motorcycle manufacturers, and ultimately, 
consumers, both here and abroad, can expect to achieve cost savings 
through the formal harmonization of differing sets of standards when 
the Contracting Parties implement the new GTR. Motorcycles are vehicles 
that are prepared for the world market. It would be more economically 
efficient to have manufacturers using the same test procedures and 
meeting the same performance requirements worldwide. This proposal 
would help achieve these benefits and thus reduce the amount of 
resources utilized to test motorcycles. Moreover, this GTR sets the 
stage for further cooperative efforts with other countries facing 
similar problems at the same or even greater exposure rates, learning 
from their experience, and leveraging resources to jointly research and 
implement more effective vehicle related interventions.\4\
---------------------------------------------------------------------------

    \4\ ``Action Plan to Reduce Motorcycle Fatalities,'' supra note 
1, at 8.
---------------------------------------------------------------------------

    Although this proposal would add and update FMVSS No. 122 
performance requirements and provide benefits from harmonization, we 
anticipate that virtually all motorcycles sold in the U.S. can meet the 
requirements as proposed. The proposal includes several tests that 
would enhance the safe operation of a motorcycle: tests both at gross 
vehicle weight rating (GVWR) and lightly loaded vehicle weight, which 
ensure adequate braking performance at the two extremes of the loading 
conditions; a wet brake test that is more representative of the manner 
in which brakes are wetted during real world riding in wet conditions; 
a variety of ABS performance tests to ensure that motorcycles equipped 
with ABS have adequate antilock performance during emergency braking or 
on slippery road conditions; and a new requirement that addresses 
failure in the power-assisted braking system.
    Given the sources and magnitude of the overall safety problem posed 
by increased motorcycle fatalities, the agency intends to address the 
problem of motorcycle safety comprehensively, focusing on regulatory as 
well as behavioral countermeasure strategies. In October 2007, the 
Secretary of Transportation announced the Action Plan to Reduce 
Motorcycle Fatalities which will help reduce motorcycle fatalities with 
new national safety and training standards, curb the use of counterfeit 
helmet labelling, place a new focus on motorcycle-specific road 
improvements, provide training for law enforcement officers on how to 
spot unsafe motorcyclists, and create a broad public awareness campaign 
on rider safety. Id. at 1.

II. Background

    FMVSS No. 122, Motorcycle brake systems, (49 CFR 571.122) took 
effect on January 1, 1974 (37 FR 1973, June 16, 1972). FMVSS No. 122 
specifies performance requirements for motorcycle brake systems. The 
purpose of the standard is to provide safe motorcycle brake performance 
under normal and emergency conditions. The safety afforded by a 
motorcycle's braking system is determined by several factors, including 
stopping distance,

[[Page 54022]]

linear stability while stopping, fade resistance, and fade recovery. A 
safe system should have features that both guard against malfunction 
and stop the motorcycle if a malfunction should occur in the normal 
service system. FMVSS No. 122 was originally conceived to cover each of 
these aspects of brake safety by specifying equipment and performance 
requirements appropriate for both two-wheeled and three-wheeled 
motorcycles. Because motorcycles differ significantly in configuration 
from other motor vehicles, the agency established a separate brake 
standard applicable only to this vehicle category. Many of the FMVSS 
No. 122 test procedures are, however, similar to those for passenger 
cars.\5\
---------------------------------------------------------------------------

    \5\ See Brake Systems on Motorcycles Proposed Motor Vehicle 
Safety Standard, 36 FR 5516 (Mar. 24, 1971).
---------------------------------------------------------------------------

    Only a few changes have been made to the regulation since it was 
established. In response to petitions, a 1974 final rule changed the 
application of FMVSS No. 122 requirements for low-speed motor-driven 
cycles (motorcycles with 5-brake horsepower or less whose speed 
attainable in one mile is 30 miles per hour or less) (39 FR 32914, 
Sept. 12, 1974). In 1978, NHTSA amended the FMVSS No. 122 parking brake 
test to clarify the test conditions and incorporate an interpretation 
applicable to three-wheeled motorcycles (43 FR 46547, Oct. 10, 1978). 
In 2001, the minimum hand lever force requirements for the heat fade 
test and water recovery test were decreased to facilitate the 
manufacture of motorcycles with combined braking systems (66 FR 42613, 
Aug. 14, 2001). Except for the above changes, FMVSS No. 122 has not 
been amended to keep pace with the advancement of modern brake 
technologies.

 III. Current Requirements of FMVSS No. 122

    FMVSS No. 122 applies to both two-wheeled and three-wheeled 
motorcycles. Among other requirements, the motorcycle manufacturer must 
ensure that each motorcycle can meet performance requirements under 
conditions specified in paragraph S6, Test conditions, and as specified 
in paragraph S7, Test procedures. The tests in S7 include pre- and 
post-burnishment effectiveness tests, a fade and recovery test, a 
partial failure test, a water recovery test, and parking brake test. At 
the end of the test procedure sequence, the brake system must pass a 
durability inspection. All stops must be made without lockup of any 
wheel.
    Equipment. Each motorcycle is required to have either a split 
service brake system or two independently actuated brake systems. The 
former system encompasses a service brake system combined with a hand 
operated parking brake system for three-wheeled motorcycles. If a 
motorcycle has a hydraulic service brake system, it must also have a 
reservoir for each master cylinder, and a master cylinder reservoir 
label advising the proper grade of brake fluid. If the service brake 
system is a split hydraulic type, a failure indicator lamp is required. 
Additionally, three-wheeled motorcycles must be equipped with a 
friction type parking brake with a solely mechanical means to retain 
engagement. The service brake system must be installed so that the 
lining thickness of the drum brake shoes may be visually inspected, 
either directly or by using a mirror without removing the drums, and so 
that disc brake friction lining thickness may be visually inspected 
without removing the pads.
    Pre- and post-burnish tests. The service brake system and each 
independently actuated service brake system on each motorcycle must be 
capable of stopping within specified distances from 30 miles per hour 
(mph) and 60 mph. The brakes are then burnished by making 200 stops 
from 30 mph at 12 feet per second per second (fps\2\). The service 
brake system must then be capable of stopping at specified distances 
from 80 mph and from a speed divisible by 5 mph that is 4 mph to 8 mph 
less than the maximum motorcycle speed. The post-burnish tests are 
conducted in the same way as the pre-burnish stops, and the service 
brakes must be capable of stopping the motorcycle within the post-
burnish specified stopping distances.
    Fade and recovery test. The fade and recovery test compares the 
braking performance of the motorcycle before and after ten 60-mph stops 
at a deceleration of not less than 15 fps\2\. As a check test, three 
baseline stops \6\ are conducted from 30 mph at 10 to 11 fps\2\, with 
the maximum brake lever and maximum pedal forces recorded during each 
stop, and averaged over the three baseline stops. Ten 60-mph stops are 
then conducted at a deceleration rate of not less than 15 fps\2\, 
followed immediately by five fade recovery stops from 30 mph at a 
deceleration rate of 10 to 11 fps\2\. The maximum brake pedal and lever 
forces measured during the fifth recovery stop must be within plus 20 
pounds and minus 10 pounds of the baseline average maximum brake pedal 
and lever forces.
---------------------------------------------------------------------------

    \6\ The baseline check is used to establish a specific 
motorcycle's pre-test performance to provide a basis for comparison 
with post-test performance. This comparison is intended to ensure 
adequate brake performance, at reasonable lever and pedal forces, 
after numerous high-speed or wet brake stops.
---------------------------------------------------------------------------

    Partial failure test. In the event of a pressure component leakage 
failure, the remaining portion of the service brake system must 
continue to operate and shall be capable of stopping the motorcycle 
from 30 mph and 60 mph within specified stopping distances. The brake 
failure indicator light must activate when the master cylinder fluid 
level decreases below the minimum specified level.
    Water recovery test. The water recovery test compares the braking 
performance of the motorcycle before and after the motorcycle brakes 
are immersed in water for two minutes. Three baseline stops are 
conducted from 30 mph at 10 to 11 fps\2\, with the maximum brake lever 
and pedal forces recorded during each stop, and averaged over the three 
baseline stops. The motorcycle brakes are then immersed in water for 
two minutes, followed immediately by five water recovery stops from 30 
mph at a deceleration rate of 10 to 11 fps\2\. The maximum brake pedal 
and lever forces measured during the fifth recovery stop must be within 
plus 20 pounds and minus 10 pounds of the baseline average maximum 
brake pedal force and the lever force.
    Parking brake test. For motorcycles required to be equipped with a 
parking brake system, such system must be able to hold the motorcycle 
on a 30 percent grade, in both forward and reverse directions, for 5 
minutes. A parking brake indicator lamp must be provided.

IV. Harmonization Efforts

    Globally, there are several existing regulations, directives, and 
standards that pertain to motorcycle brake systems. As all share 
similarities, the Contracting Parties to the 1998 Agreement under WP.29 
tentatively determined that the development of a GTR under the 1998 
Agreement would be beneficial. During the 126th session of WP.29 of 
March 2002, the Executive Committee of the 1998 Agreement adopted a 
Program of Work, which included the development of a GTR on motorcycle 
brake systems. Subsequently, Canada offered to sponsor the GTR on 
motorcycle braking requirements at the 52nd session of the Working 
Party for Brakes and Running Gear (GRRF), in September 2002.\7\ To

[[Page 54023]]

proceed with the development of the GTR, the Executive Committee 
endorsed Canada's request to establish and chair an informal group on 
motorcycle brakes, at the 130th session of WP.29 in June 2003.
---------------------------------------------------------------------------

    \7\ The Working Party for Brakes and Running Gear (GRRF) is made 
up of delegates from many countries around the world, and who have 
voting privileges. Representatives from manufacturing and consumer 
groups also attend and participate in the GRRF and informal working 
groups that are developing GTRs. Those that chose not to participate 
are kept apprised of the GTR progress from progress reports which 
are presented at the GRRF meetings and then posted on the UN's Web 
site.
---------------------------------------------------------------------------

    In an effort to select the best of existing performance 
requirements for a GTR, the U.S. and Canada conducted analyses of the 
relative stringency of three national motorcycle brake system 
regulations. These were the UNECE Regulation No. 78, FMVSS No. 122, and 
the Japanese Safety Standard JSS 12-61. The subsequent reports, along 
with proposed provisions of a GTR, were presented at GRRF meetings, and 
will be available in the docket. While using different methodologies, 
the results from the U.S./Canada report were similar to an industry-led 
report that examined the issue under the GRRF. These studies completed 
by the U.S., Canada, and the industry provided the basis for the 
development of the technical requirements of the GTR.
    The following regulations, directives and international voluntary 
standards were considered and used as the basis for the development of 
the GTR:
     UNECE Regulation No. 78--Uniform provisions concerning the 
approval of vehicles of category L with regard to braking.
     FMVSS No.122, Motorcycle brake systems.
     Canada Motor Vehicle Safety Regulation No. 122--Motorcycle 
brake systems. (CMVSS No. 122).

    Note: FMVSS and CMVSS No. 122 are substantially similar.

     Japan Safety Standard JSS12-61.
     Australian Design Rule 33/00--Brake systems for 
motorcycles and mopeds.
     International Organization for Standardization (ISO) 
8710:1995, Motorcycles--Brakes and braking devices--tests and 
measurement methods.
     ISO 12364:2001, Two-wheeled motorcycles--Antilock braking 
systems (ABS)--tests and measurement methods.
     ISO 12366:2001, Two-wheeled mopeds--Antilock braking 
systems (ABS)--tests and measurement methods.
    The informal group used the feedback from the GRRF presentations to 
assist with the completion of the proposed GTR, a copy of which is 
being placed in the docket.\8\ Where national regulations or standards 
address the same subject, e.g., dry stop or heat fade performance 
requirements, the informal group reviewed comparative data on the 
relative stringency of the requirements from the research and studies 
and included the most stringent options. Additional testing was 
conducted to confirm or refine the testing and performance 
requirements. Qualitative issues, such as which wet brake test to 
include, were discussed on the basis of the original rationales and the 
appropriateness of the tests to modern conditions and technologies. In 
each of these steps, specific technical issues were raised, discussed, 
and resolved, as discussed below. The informal working group held a 
total of eight meetings concerning the development of the GTR. In 
November 2006, WP.29 approved the GTR on Motorcycle Brake Systems, and 
established it in the Global Registry as Global Technical Regulation 
No. 3.
---------------------------------------------------------------------------

    \8\ The first formal proposal for a GTR concerning motorcycle 
brake systems was presented during the 58th GRRF session in 
September 2005. A more detailed report on the technical details, 
deliberations and conclusions, which led to the proposed GTR, was 
provided separately as informal document No. GRRF-58-16. Both 
documents will be available in the docket.
---------------------------------------------------------------------------

    The GTR on motorcycle brake systems consists of a compilation of 
the most stringent and relevant test procedures and performance 
requirements from current standards and regulations. As a result of the 
comparison process, the selected performance requirements of the GTR 
are mainly drawn from the UNECE Regulation No. 78, the FMVSS No. 122 
and the Japanese Safety Standard JSS 12-61 (JSS 12-61). The GTR is 
comprised of several fundamental tests, each with their respective test 
procedures and performance requirements. These tests and procedures are 
listed below along with the national regulation on which they are 
based:
     Burnish procedure (FMVSS No. 122)
     Dry stop test with each service brake control actuated 
separately (UNECE Regulation No. 78/JSS 12-61)
     Dry stop test with all service brake systems applied 
simultaneously (FMVSS No. 122)
     High speed test (JSS 12-61)
     Wet brake test (UNECE Regulation No. 78/JSS 12-61)
     Heat fade test (UNECE Regulation No. 78/JSS 12-61)
     Parking brake test (UNECE Regulation No. 78/JSS 12-61)
     ABS tests (UNECE Regulation No. 78/JSS 12-61)
     Partial failure test--split service brake systems (FMVSS 
No. 122)
     Power-assisted braking system failure test (new)
    The GTR process was transparent to country delegates, industry 
representatives, public interest groups, and other interested parties. 
Information regarding the meetings and negotiations was publicly 
available through notices published periodically by the agency and UN 
Web site.\9\ In the U.S., NHTSA published notice of its intent to add 
motorcycle brake systems to its list of recommendations of standards 
for consideration as a GTR in January 2001 (66 FR 4893, Jan. 18, 2001; 
Docket No. NHTSA-00-7538). The agency later published notice that 
Canada had submitted a proposal for the establishment of a motorcycle 
brakes GTR, and sought public comment on the formal proposal (69 FR 
60460, Oct. 8, 2004; Docket No. NHTSA-03-14395). In October 2006, NHTSA 
published a further update on the status of the proposed motorcycle 
brake systems GTR, and requested comments specific to the motorcycle 
brakes GTR and NHTSA's intent to vote positively on behalf of the 
United States for its establishment (71 FR 59582, Oct. 10, 2006; Docket 
No. NHTSA-2003-14395). The agency did not receive comments in response 
to any of these notices regarding the motorcycle brake systems GTR.
---------------------------------------------------------------------------

    \9\ See https://www.unece.org/trans/main/wp29/wp29wgs/wp29grrf/
grrf-infmotobrake7.html for a record of all GRRF meetings and 
documents presented therein.
---------------------------------------------------------------------------

V. Proposed Improvements to FMVSS No. 122

A. General

1. New Terminology
    For this proposal, definitions in FMVSS No. 122 (paragraph S4) were 
revised or added where necessary, such as new proposed terms used to 
describe antilock brake systems (ABS), vehicle maximum speed (Vmax), 
and peak braking coefficient (PBC). Additionally, in order to 
streamline the proposed regulatory text to more closely reflect the GTR 
text, some of the new proposed terms are common terminology and 
definitions based on the UN document titled ``Special Resolution No. 1 
Concerning the Common Definitions of Vehicle Categories, Masses and 
Dimensions (S.R.1)'' \10\ (UN Doc. S.R.1) developed for the purposes of 
the GTRs. Thus, certain new definitions that may

[[Page 54024]]

be similar to existing 49 CFR Part 571 definitions are proposed to be 
added to Sec.  571.122 S4, Definitions. For example, current FMVSS No. 
122 specifies that performance requirements must be met when the 
``motorcycle weight is unloaded vehicle weight plus 200 pounds.'' \11\ 
This is effectively equivalent to the mass term ``lightly loaded'' in 
the proposed rule, which is the testing condition specified for the 
proposed dry stop test--all service brake controls actuated, the high-
speed test, the antilock brake systems tests, and the partial failure 
test.\12\ These proposed terms, some of which may be similar or 
equivalent to existing terms defined elsewhere in 49 CFR Part 571, are 
used in the motorcycle brakes GTR in an effort to streamline the GTR 
and maximize harmonization benefits.
---------------------------------------------------------------------------

    \10\ World Forum for Harmonization of Vehicle Regulations 
(WP.29), Special Resolution No. 1 Concerning the Common Definitions 
of Vehicle Categories, Masses and Dimensions (S.R.1), U.N. Doc. 
TRANS/WP.29/1045 (Sept. 15, 2005), available at https://
www.unece.org/trans/doc/2005/wp29/TRANS-WP29-1045e.pdf.
    \11\ 49 CFR 571.122, S6.1. ``Unloaded vehicle weight'' is 
defined under 49 CFR 571.3(b) to mean ``the weight of a vehicle with 
maximum capacity of all fluids necessary for operation of the 
vehicle, but without cargo, occupants, or accessories that are 
ordinarily removed from the vehicle when they are not in use.''
    \12\ Lightly loaded means the sum of unladen vehicle mass (mass 
of the vehicle with bodywork and all factory fitted equipment, and 
fuel tanks filled to at least 90 percent) and driver mass ``plus 15 
kg for test equipment, or the laden condition, whichever is less.'' 
FMVSS No. 122 S4, Definitions (proposed).
---------------------------------------------------------------------------

    Additionally, the proposed rule divides motorcycles into five 
categories, which are referenced in the GTR. These motorcycle 
categories are based on number of wheels and maximum speed, and were 
originally defined in the UN Doc. S.R.1, as amended in May 2007.\13\ We 
included these categories in the definitions portion of proposed FMVSS 
No. 122 because under the GTR some performance tests do not apply to 
certain motorcycle categories, and certain motorcycle categories have 
different performance requirements than others.
---------------------------------------------------------------------------

    \13\ See WP.29, Amendment to Special Resolution No. 1 Concerning 
the Common Definitions of Vehicle Categories, Masses, and 
Dimensions, U.N. Doc. ECE/TRANS/WP.29/1045/Amend.1 (May 9, 2007), 
available at https://www.unece.org/trans/main/wp29/wp29wgs/wp29gen/
wp29fdoc/1000/ECE-TRANS-WP29-1045a1e.pdf.
---------------------------------------------------------------------------

    Category 3-1 and category 3-3 motorcycles are two-wheeled 
motorcycles. Category 3-1 motorcycles are two-wheeled motorcycles with 
an engine cylinder capacity not exceeding 50 cm\3\ and a maximum design 
speed not exceeding 50 kilometers per hour (km/h). Category 3-3 
motorcycles are two-wheeled motorcycles with an engine cylinder 
capacity exceeding 50 cm\3\ or a maximum design speed exceeding 50 km/
h. Category 3-2 motorcycles are three-wheeled motorcycles of any wheel 
arrangement with an engine cylinder capacity not exceeding 50 cm\3\ and 
a maximum design speed not exceeding 50 km/h. Category 3-4 motorcycles 
are those manufactured with three wheels asymmetrically arranged in 
relation to the longitudinal median plane with an engine cylinder 
capacity exceeding 50 cm\3\ or a maximum design speed exceeding 50 km/
h. Finally, category 3-5 motorcycles are motorcycles manufactured with 
three wheels symmetrically arranged in relation to the longitudinal 
median plane with an engine cylinder capacity exceeding 50 cm\3\ or a 
maximum design speed exceeding 50 km/h.
2. Vehicle Test Speed and Corrected Stopping Distance
    Deceleration or stopping distance performance requirements are set 
for a specified initial test speed. While professional test riders can 
approach this initial test speed, it is unlikely that the test will be 
started at the exact speed specified, affecting the stopping distance 
measurement. The current FMVSS No. 122 does not specify a speed 
tolerance for this potential variation, but consistent with the GTR, 
the proposed rule specifies Japan's existing general tolerance of 
5 km/h in S6.1.4.
    A method for correcting the measured stopping distance is specified 
in JSS 12-61 to compensate for the difference between the specified 
test speed and the actual speed where the brakes were applied. Although 
not specified directly in the regulations, the current FMVSS No. 122 
and CMVSS No. 122 also apply a correction factor to test data, using 
the method specified in Society of Automotive Engineers (SAE) standard 
J299, Stopping Distance Test Procedure. The informal group evaluated 
the above noted stopping distance correction methods and the one 
specified in ISO 8710:1995, Motorcycles--Brakes and braking devices--
tests and measurement methods.
    SAE J299 offers the most basic method for estimating the corrected 
distance, and the method is applicable to a speed tolerance of  3.2 km/h ( 2 mph). The ISO 8710 and JSS 12-61 
methods are based on the same principles, but also take into 
consideration the brake system reaction time. These methods are 
applicable to a wider speed tolerance of  5 km/h. However, 
a small error in handling the system reaction time is apparent in the 
ISO 8710 equation, which results in higher than expected corrected 
values. Based on this analysis, the informal group agreed that the 
stopping distance correction method specified in JSS 12-61 was the most 
appropriate for the GTR. Therefore, as with the existing Japanese 
standard, the specified test speeds in the GTR include a general 
tolerance of  5 km/h (S6.1.4), using the JSS stopping 
distance correction method to normalize the measured test results, if 
necessary, to compensate for the difference between the specified test 
speed and the actual speed where the brakes were applied (see 
S5.3.2(b)).
3. Test Method To Measure Peak Braking Coefficient
    The peak braking coefficient (PBC) is a measure of the coefficient 
of friction of the test surface and is an important parameter in 
evaluating the brake performance of a vehicle. PBC is effectively 
equivalent to the peak friction coefficient (PFC) as defined in FMVSS 
No. 121, Air brake systems, and FMVSS No. 135, Light vehicle brake 
systems. The GTR specifies test surface conditions, one of which is 
that the high-friction ``test surface has a nominal [PBC] of 0.9, 
unless otherwise specified.'' For reasons of objectivity, we are 
specifying in the proposed rule a PBC equal to 0.9 for the high-
friction dry test surface used for the motorcycle brake system tests. 
NHTSA has discussed the issues surrounding objective measurement of 
PBC/PFC at length in an early-1990s rulemaking that added ABS 
requirements for medium and heavy vehicles (see e.g., 60 FR 13216, Mar. 
10, 1995; Docket Nos. 92-29, 93-69).
    FMVSS No. 122 currently specifies that the road tests be conducted 
on an 8-foot-wide level roadway having a skid number of 81. The skid 
number is also a measure of the coefficient of friction of the test 
surface and is derived by measuring the friction using a locked wheel, 
whereas the PBC is derived by measuring the peak surface friction 
before wheel lockup occurs. PBC is a more relevant surface friction 
measurement for non-locked wheel tests, as those included in FMVSS No. 
122 and in the GTR. Other Federal motor vehicle safety standards for 
braking systems, FMVSS No. 121 and FMVSS No. 135, specify the road test 
surface using PBC of 0.9 when measured using the American Society for 
Testing and Materials (ASTM) E1136-93 (Reapproved 2003) standard 
reference test tire, in accordance with ASTM Method E1337-90 
(Reapproved 2002), at a speed of 40 mph without water delivery.
    The UNECE Regulation No. 78 and the JSS 12-61 do not specify the 
coefficient of friction for the test surface but prescribe that the 
test surface be level, dry, and affording good adhesion. For the ABS 
tests where road surface

[[Page 54025]]

friction requirements are specified, the UNECE Regulation No. 78 and 
JSS 12-61 specify a method that is based on the same principles as 
measuring the PBC. This is determined by finding the wheel lock 
threshold through a series of braking tests with the ABS disabled for 
the individual motorcycle being evaluated, and uses the tires on the 
motorcycle compared with the ASTM Method, which uses a reference test 
(control) tire on a skid trailer.
    The GTR defines the test surface using a PBC value instead of a 
skid number value since peak braking coefficient is a more 
representative measure of the type of braking tests performed in the 
requirements with a rolling tire. However, the decision was made to not 
specify the method used to measure the coefficient of friction but 
leave it to the national regulations to specify which of the above test 
methods should be used to measure PBC. In the U.S., the ASTM Method for 
measuring PBC to define surface friction has been included in Federal 
motor vehicle safety standards since the early-1990's and was also used 
by the U.S. automotive industry prior to that date. Accordingly, the 
agency proposes that the PBC of the test surface will be measured using 
the ASTM E1136-93 (Reapproved 2003) standard reference test tire, in 
accordance with ASTM Method E1337-90 (Reapproved 2002).
    As mentioned above, the GTR also maintains an option for 
Contracting Parties to specify in their respective national regulations 
the value of PBC for the high-friction dry test surface used for the 
motorcycle brake system tests. Because of objectivity concerns, we are 
proposing a PBC of 0.9 as opposed to a nominal PBC of 0.9 (the default 
option in the GTR).
4. Test Sequence
    We are proposing a specific testing order to eliminate any 
potential effect of the test sequence on braking performance and to 
harmonize with the GTR. The proposed sequence was selected based on 
increasing severity of the test on the motorcycle and its brake 
components, in order to preserve the condition of the brakes.
    The current FMVSS No. 122 specifies a particular sequence in which 
tests should be conducted, ending with the wet brake test. The purpose 
here is to minimize the variability of test results through consistency 
in both the condition of the brakes throughout the tests and in the way 
in which the brakes are evaluated. There is no specified test order in 
the UNECE Regulation No. 78. Similarly, JSS 12-61 indicates that tests 
can be done in any order, with the exception that the fade test be 
conducted last.
    The fade test would have the greatest effect on the condition of 
the motorcycle brakes, which could affect brake performance in 
subsequent tests. For this reason, current FMVSS No. 122 specifies that 
a re-burnishing be conducted after the fade test, to refresh the brake 
components. In order to eliminate the need for re-burnishing, the GTR 
specifies that the fade test be the last of the motorcycle brake system 
performance tests, which is consistent with the existing practice in 
JSS 12-61.
    The ABS test would be the next most severe test, which will result 
in braking at or near the limits of traction. Thus, the GTR specifies 
that the ABS test would precede the fade test, for motorcycles equipped 
with ABS. The remaining tests are not as severe on the brake system and 
tires, therefore the GTR sequenced them according to increasing test 
speed for the dry stop performance tests, followed by the wet brake 
performance test.
    Consistent with the GTR, we are proposing a specified test sequence 
as follows:
    (1) Dry stop test--single brake control actuated;
    (2) Dry stop test--all service brake controls actuated;
    (3) High speed test;
    (4) Wet brake test;
    (5) If fitted:
    (a) Parking brake system test;
    (b) ABS test;
    (c) Partial failure, for split service brake systems test;
    (d) Power-assisted braking system failure test.
    (6) Heat fade test.
    The informal group that developed the technical specifications for 
the GTR assessed alternatives to the testing sequence, including 
selecting a test sequence based on the loading of the motorcycle in 
order to save time, and relocating the wet brake test to second-last, 
before the final fade test. Either option would place the more severe 
brake tests earlier in the test sequence, which could affect braking 
performance in subsequent tests. The GTR therefore kept the test 
sequence as noted above.
5. Brake Application Force Measurement
    Controls for the application of the brakes can include hand and 
foot actuated control levers. The various national standards and 
regulations have slightly different brake control input force limits, 
and in the case of a hand actuated control lever, there is also a 
discrepancy as to the location of application of the input force. One 
consistent element is the location and direction of application of the 
input force to the foot actuated lever (i.e. pedal). Consistent with 
the GTR, the proposed rule specifies input forces in accordance with 
the national regulation on which the individual test is based, to 
minimize confusion.
    The respective input forces are noted in the following table:

 
------------------------------------------------------------------------
                                   Foot control, FP    Hand control, FL
           Regulation                     (N)                 (N)
------------------------------------------------------------------------
FMVSS No. 122...................  25 < FP < 400.....  10 < FL < 245
UNECE Regulation No. 78/JSS 12-   FP < 350..........  FL < 200
 61.
------------------------------------------------------------------------

A discussion on brake control actuation force specifications for 
evaluating motorcycles equipped with ABS is provided below in paragraph 
V.B.7.
    With respect to the location of the input force on the hand-
controlled lever, UNECE Regulation No. 78 and JSS 12-61 place the input 
force 50 mm from the end of the lever, while FMVSS No. 122 locates the 
input force 30 mm from the end of the handle bar grip. On most models 
(but not all), the control lever typically extends slightly beyond the 
handle bar grip, such that the control forces are almost at the same 
location regardless of the method followed. Depending on the 
regulation, however, it is not entirely clear whether this measurement 
should be taken along the length of the control lever or parallel to 
the handle bar grip; or, how to measure with a curved or angled control 
lever. Some interpretation is required.
    In developing the GTR, there was agreement that none of the three 
national regulations is clear enough with respect to measuring the 
location of the input force on the hand-controlled lever. In an effort 
to define a common practice, the GTR includes a

[[Page 54026]]

revised description for the location of the input force on the control 
lever and its direction of application, based on ISO 8710:1995, 
Motorcycles--Brakes and braking devices--tests and measurement methods. 
This proposed rule adopts the GTR's harmonized specification of input 
force.
    Finally, for those motorcycles that use hydraulic fluid for brake 
force transmission, the GTR stipulates that the master cylinder shall 
have a sealed, covered, separate reservoir for each brake system. This 
includes one or more separate reservoirs located within the same 
container, such as commonly found on passenger cars. Such containers 
may only have one sealed, covered filling cap. The proposed rule 
incorporates these hydraulic service brake system requirements in 
S5.1.9.
6. Brake Temperature Measurement
    Brake test requirements typically specify that initial brake 
temperature (IBT) be measured at the start of each braking performance 
run to enhance test repeatability. The two measurement methods that are 
generally used in brake standards and regulations worldwide include (1) 
the use of plug-type thermocouples, and (2) the use of rubbing-type 
thermocouples. We propose to retain the plug-type thermocouples brake 
temperature measurement method in FMVSS No. 122.
    Plug-type thermocouples are imbedded in the brake friction material 
(brake pad for disc brakes or brake shoes for drum brakes) one 
millimeter below the contact surface between the friction material and 
the brake disc or brake drum. This placement of the thermocouple allows 
no contact with the friction surfaces and provides an accurate reading 
of the temperature at the friction material/disc or drum interface. 
Rubbing-type thermocouples are placed so that they are in direct 
contact with both the friction material and the disc or drum. Although 
this type of thermocouple can provide a quicker response to temperature 
changes, it has some limitations regarding its durability and its 
effectiveness when used on brakes with cross-drilled or grooved discs. 
In addition, for a given brake system, the rubbing-type thermocouple 
generally provides higher temperature readings compared with the plug-
type thermocouple.
    The two methods of measuring the IBT were included in the GTR and 
each Contracting Party may specify which temperature measurement would 
be accepted in its national regulation. FMVSS No. 122, as well as all 
the other brake standards in the Federal motor vehicle safety 
standards, currently specifies the plug-type thermocouple for measuring 
the initial brake temperature. UNECE Regulation No. 78 and JSS 12-61 
also prescribe brake temperature measurement, but neither regulation 
makes reference to specific measurement equipment or installation 
methods. NHTSA does not have experience using the rubbing-type 
thermocouple either in brake research or compliance testing. Given the 
limitations of the rubbing-type thermocouple, we believe that the plug-
type thermocouple would be the more effective option for measuring IBT 
in the proposed FMVSS No. 122. Therefore, the proposed rule specifies 
that initial brake temperature is measured by plug-type thermocouples.
    With respect to the actual brake temperature values specified for 
testing purposes, each of the national regulations on which the GTR 
performance requirements are based specifies a value for the IBT. For 
most tests, the UNECE Regulation No. 78 and JSS 12-61 specify that the 
IBT shall be less than or equal to 100 [deg]C (212 [deg]F), whereas 
FMVSS No. 122 specifies an IBT between 55 [deg]C and 65 [deg]C (130 
[deg]F and 150 [deg]F). In developing the GTR, it was agreed that a 
narrow IBT range could improve the repeatability of the performance 
tests. However, test data indicated that the narrow range specified by 
FMVSS No. 122 might not be achievable for those motorcycles equipped 
with a combined brake system. Therefore, the GTR specifies an IBT 
between 55 [deg]C and 100 [deg]C in order to encompass all brake 
systems, and the proposed rule specifies this same IBT range as a test 
condition.
7. Burnishing Procedure
    The current FMVSS No. 122 includes a burnishing procedure. In order 
to harmonize with the GTR, we are proposing a slight variation of the 
current procedure, to include some aspects of procedures currently used 
by motorcycle manufacturers in preparation for UNECE Regulation No. 78/
JSS 12-61 type approval testing.
    The burnishing procedure serves as a conditioning of the foundation 
brake components to permit the brake system to achieve its full 
capability. Burnishing typically matches the friction components to 
one-another and results in more stable and repeatable stops during 
testing. UNECE Regulation No. 78 and JSS 12-61 do not include any 
burnishing procedure. Under the UNECE and the JSS regulations, the 
motorcycle is generally presented for type approval compliance testing 
in a burnished condition, using a procedure determined by the 
motorcycle manufacturer. All Federal motor vehicle safety standards for 
brake systems (FMVSS Nos. 105, 121, 122 and 135) currently include a 
burnishing procedure. The burnishing procedure of FMVSS No. 122 
specifies 200 stops with both brakes applied simultaneously, 
decelerating from a speed of 30 mph at 12 fps\2\ with an IBT between 55 
[deg]C and 65 [deg]C (130 [deg]F and 150 [deg]F).
    The burnishing procedure in the GTR is based on FMVSS No. 122, but 
also includes some aspects of procedures currently used by motorcycle 
manufacturers in preparation for UNECE Regulation No. 78/JSS 12-61 type 
approval testing. For example, the initial speed proposed for the 
procedure has been changed to 50 km/h to round-off the metric 
equivalent, which is a slight increase from 30 mph (48 km/h) as 
specified by FMVSS No. 122. An initial speed of 0.8 Vmax was adopted 
for category 3-1 and 3-2 motorcycles, which have a Vmax of 50 km/h or 
less. Instead of making complete stops, the proposal also includes 
braking the motorcycle at the specified deceleration down to a speed 
between 5 km/h and 10 km/h, after which the motorcycle may be 
accelerated to the initial test speed for the next stop in the 
burnishing procedure. The primary reason for not braking the motorcycle 
to a complete stop is to expedite the burnishing procedure. The 
increased motorcycle kinetic energy resulting from the small initial 
speed increase of 2 km/h is likely to offset any reduction in kinetic 
energy resulting from not braking the motorcycle until a complete stop 
is reached. The GTR specifies burnishing the brakes separately since 
this would result in a more complete burnish for both front and rear 
brakes, as compared with the current FMVSS No. 122 method of using both 
brakes simultaneously. Hence, consistent with the GTR, the proposed 
rule specifies that each brake be burnished for 100 decelerations.
    Finally, the GTR changes the IBT from the range of 55 [deg]C to 65 
[deg]C currently specified in FMVSS No. 122 to an IBT less than or 
equal to 100 [deg]C. The primary reasons for changing the IBT are to 
accommodate the higher operational temperatures of motorcycles equipped 
with disc brakes and to reduce the cooling times between stops. In 
developing the GTR, it was agreed that although a narrow IBT range is 
important to achieve good repeatability of the performance tests, the 
IBT range is not as critical for the burnishing procedure.

[[Page 54027]]

8. Notice of Wear
    We are proposing the GTR requirement that ``friction material 
thickness shall be visible without disassembly, or where the friction 
material is not visible, wear shall be assessed by means of a device 
designed for that purpose.'' FMVSS No. 122 S5.2.2, Notice of wear 
(proposed). Current FMVSS No. 122 requires that the ``brake system [ ] 
be installed so that the lining thickness of drum brake shoes may be 
visually inspected, either directly or by use of a mirror without 
removing the drums, and so that disc brake friction lining thickness 
may be visually inspected without removing the pads.'' FMVSS No. 122 
S5.1.5, Other requirements. Allowing wear of friction material 
thickness to be assessed either visually or by means of a device 
increases design freedom while serving the same purpose of indicating 
friction material wear, without the need for disassembly.

B. Specific Performance Tests

1. Dry Stop Test--Single Brake Control Actuated
    The GTR has a provision for a dry stop test with single brake 
control that is based on UNECE Regulation No. 78 and JSS 12-61 tests. 
Current FMVSS No. 122 does not have a requirement that tests each brake 
system separately in a split brake service system, but only a 
requirement that tests the front and rear brake simultaneously. In the 
main FMVSS No. 122 dry stop test with both brake controls actuated 
simultaneously, the test rider judges how to apportion the force 
actuated to the front and rear brakes. This may give less repeatable 
test results or allow the test rider to compensate for a ``weak'' 
brake. As such, an additional test specifying that each split brake be 
tested individually would improve FMVSS No. 122.
    The purpose of a dry stop test requirement with the separate 
actuation of each brake control is to ensure a minimum level of 
motorcycle braking performance on a dry road surface for each 
independent brake system. Each of the major national motorcycle brake 
regulations, UNECE Regulation No. 78, FMVSS No. 122, and JSS 12-61, 
includes a dry stop test in its test procedures. The UNECE Regulation 
No. 78 and the JSS 12-61 test procedures and performance requirements 
are similar. The UNECE Regulation No. 78 and JSS 12-61 regulations 
require that the braking performance be evaluated separately for each 
brake control, with the motorcycle in the laden condition and at test 
speeds of 40 km/h or 60 km/h depending on the motorcycle category. The 
only exception is for motorcycle category 3-4, where it is specified 
that the brakes at all wheels shall be operated via a single foot 
actuated control.
    Current FMVSS No. 122 performance requirements are quite different 
as they specify motorcycles be tested in what is effectively the 
lightly-loaded condition,\14\ and with all brake controls actuated 
simultaneously. The exception is the pre-burnish test requirements, 
which specify that each independently actuated service brake system 
must be capable of stopping the motorcycle (in effectively the lightly-
loaded condition) within specified stopping distances. Current FMVSS 
No. 122 also specifies test requirements from 30 mph (48.3 km/h), 60 
mph (96.6 km/h) and 80 mph (128.8 km/h). Consistent with being tested 
in the lightly-loaded condition and with both brakes applied together, 
the FMVSS No. 122 deceleration requirements are higher than in the 
UNECE Regulation No. 78 and JSS 12-61. The FMVSS No. 122 and the UNECE 
Regulation No. 78/JSS 12-61 tests are conducted with the engine 
disconnected, which means that only the foundation brake performance is 
measured and engine braking is not a factor. Although current FMVSS No. 
122 also specifies that independent service brake systems be evaluated 
separately, that test is conducted with the brakes in the pre-burnished 
condition, hence requiring a lower level of performance.
---------------------------------------------------------------------------

    \14\ As mentioned above, current FMVSS No. 122 specifies that 
performance requirements must be met when the ``motorcycle weight is 
unloaded vehicle weight plus 200 pounds.'' 49 CFR 571.122, S6.1. 
``Unloaded vehicle weight'' is defined under 49 CFR 571.3(b) to mean 
``the weight of a vehicle with maximum capacity of all fluids 
necessary for operation of the vehicle, but without cargo, 
occupants, or accessories that are ordinarily removed from the 
vehicle when they are not in use.'' This current FMVSS No. 122 test 
mass condition is effectively equivalent to the mass condition 
``lightly loaded'' in the proposed rule. Lightly loaded means the 
sum of unladen vehicle mass (mass of the vehicle with bodywork and 
all factory fitted equipment, and fuel tanks filled to at least 90 
percent) and driver mass ``plus 15 kg for test equipment, or the 
laden condition, whichever is less.'' FMVSS No. 122 S4, Definitions 
(proposed).
---------------------------------------------------------------------------

    In independent studies of the relative severity of the tests as 
they apply to category 3-3 motorcycles, the industry concluded that the 
UNECE Regulation No. 78/JSS 12-61 test was marginally more stringent, 
whereas the NHTSA/Transport Canada findings indicated that the FMVSS 
No. 122 test was marginally more stringent.\15\ Despite the difference 
in these findings, neither study demonstrated a significant difference 
in stringency between these national regulations.
---------------------------------------------------------------------------

    \15\ These studies will be posted in the current docket.
---------------------------------------------------------------------------

    The primary advantage of the UNECE Regulation No. 78/JSS 12-61 
requirement is that each brake control is tested separately, which 
ensures that each independent brake system meets specific performance 
criteria. As mentioned above, in the main FMVSS No. 122 dry stop test 
with both brake controls actuated simultaneously, the test rider judges 
how to apportion the force actuated to the front and rear brakes. This 
may give less repeatable test results or allow the test rider to 
compensate for a ``weak'' brake. Therefore, consistent with the GTR, 
the proposed rule includes the dry stop test with single brake control 
based on UNECE Regulation No. 78/JSS 12-61 requirements. Unlike present 
UNECE/JSS national standards, the performance requirement can be met 
only through measurement of the stopping distance.
2. Dry Stop Test--All Service Brake Controls Actuated
    The GTR contains a provision to test the service brakes with the 
brake control applied simultaneously, which is very similar to the 
current FMVSS No. 122 dry stop test with both brake controls actuated 
simultaneously. The purpose of this test with all service brake 
controls actuated is to evaluate the full braking performance of 
motorcycles from a speed of 100 km/h with both front and rear brakes 
applied simultaneously. The current FMVSS No. 122 includes a stopping 
distance test from 60 mph (96 km/h) with all brake controls actuated 
simultaneously, with the motorcycle in the lightly-loaded condition. 
The stopping distance requirement from this speed is 185 feet (56.4 
meters), which is equivalent to an average deceleration of 6.4 m/s\2\ 
over the entire stop. The current requirements of UNECE Regulation No. 
78 and JSS 12-61 do not include a performance test from such a speed.
    The GTR performance specifications are based on the FMVSS No. 122 
test noted above. These test parameters are relevant since they 
represent the typical operating conditions of a motorcycle with a 
single rider traveling at highway speeds. In addition, testing in the 
lightly loaded condition with a full brake application helps to 
evaluate motorcycle stability during braking. Consistent with the GTR, 
in the proposed rule this test would apply to motorcycle categories 3-
3, 3-4 and 3-5, but not to motorcycle categories 3-1 and 3-2. The 
latter are motorcycles with a maximum speed of less than 50 km/h. Given 
this speed restriction, motorcycle categories 3-1 and 3-2 will use a 
test speed based on

[[Page 54028]]

90 percent of the maximum speed, or almost at the same exact speed as 
the 40 km/h test speed for the dry stop test--single brake control 
actuated. As the level of stringency was deemed comparable for both dry 
stop tests, it was agreed that specifying a dry stop test with all the 
service brake controls actuated for motorcycle categories 3-1 and 3-2 
would be redundant.
    The brake application force specified in the GTR is less than or 
equal to 245 N for hand levers and less than or equal to 400 N for foot 
pedals. Since this GTR performance requirement is adopted from FMVSS 
No. 122, with a slight increase in speed to 100 km/h from 96 km/h, the 
GTR retained the corresponding control lever/pedal force parameters to 
maintain the stringency of the original test. If this dry stop test was 
adopted with the force parameters from UNECE Regulation No. 78 and JSS 
12-61 Standards (200 N/350 N for the hand lever/foot pedal controls, 
respectively), it would increase the stringency of the test since it 
would effectively be proposing that the current FMVSS No. 122 
performance requirements be met with lower application forces.
    The stopping distance performance requirement from a speed of 100 
km/h is 198.5 feet (60.5 meters). In keeping with the original 
requirements on which this test is based (rounded to 100 km/h), the GTR 
maintains the performance requirement for this dry stop test in terms 
of stopping distance only.
    The approach for setting forth the performance requirements in 
current FMVSS No. 122 is to specify progressively higher performance 
requirements at set break points as test speeds decrease, based mainly 
on the fact that the PBC increases as the motorcycle speed decreases. 
When viewed in the context of FMVSS No. 122, the placement of break 
points are provided to accommodate the current FMVSS No. 122 test 
requirements from speeds of 30 mph, 60 mph, 80 m