FMVSS 122: Motorcycle Brake Systems explained.

What FMVSS 122 says it is for

The eCFR heads this section "Standard No. 122; Motorcycle brake systems." Under 49 CFR part 571, the Federal Motor Vehicle Safety Standards are the numbered standards that set safety performance requirements for motor vehicles and equipment. The text below is quoted from 571.122 as current through October 29, 2026.

This standard specifies requirements for motorcycle service brake systems and, where applicable, associated parking brake systems.

The purpose of the standard is to ensure safe motorcycle braking performance under normal and emergency riding conditions.

What it applies to

The application section of the standard says:

This standard applies to category 3-1 motorcycles, category 3-2 motorcycles, category 3-3 motorcycles, and category 3-4 motorcycles manufactured on and after September 1, 2014. This standard applies to category 3-5 motorcycles manufactured on and after September 1, 2015. At the manufacturer's option, any motorcycle manufactured on or after October 23, 2012 may comply with this standard.

Applicability is decided by the text of the standard as written, including any exclusions it lists, and by the date-specific rules in it. This page does not decide whether a particular vehicle or item is covered.

How the standard is organized

The eCFR text of 571.122 has these top-level sections:

• S1: Scope
• S2: Purpose
• S3: Application
• S4: Definitions
• S5: General requirements
• S6: Test conditions, procedures and performance requirements

In all, the text has 109 numbered headings. Use the finder above to search them; for example, a search for "test" lists the headings that mention tests.

Second-level headings at a glance

These are the numbered sub-sections one level below the top, in order (first 14 of 14):

• S5.1 Brake system requirements
• S5.2 Durability
• S5.3 Measurement of dynamic performance
• S6.1 General
• S6.2 Preparation
• S6.3 Dry stop test—single brake control actuated
• S6.4 Dry stop test—all service brake controls actuated
• S6.5 High speed test
• S6.6 Wet brake test
• S6.7 Heat fade test
• S6.8 Parking brake system test—for motorcycles with parking brakes
• S6.9 ABS tests
• S6.10 Partial failure test—for split service brake systems
• S6.11 Power-assisted braking system failure test

Key requirements, quoted from the text

These are excerpts from the requirements sections of 571.122, in the order the standard presents them. Long paragraphs are shortened where marked with [...]; the eCFR has the complete text, tables and figures, which this page omits.

S5.1 Brake system requirements. Each motorcycle shall meet each of the test requirements specified for a motorcycle of its category and for those brake features on the motorcycle.

S5.1.1 Service brake system control operation. Each motorcycle shall have a configuration that enables a rider to actuate the service brake system control while seated in the normal driving position and with both hands on the steering control.

S5.1.2 Secondary brake system control operation. Each motorcycle shall have a configuration that enables a rider to actuate the secondary brake system control while seated in the normal driving position and with at least one hand on the steering control.

S5.1.3 Parking brake system. (a) If a parking brake system is fitted, it shall hold the motorcycle stationary on the slope prescribed in S6.8.2. The parking brake system shall: (1) have a control which is separate from the service brake system controls; and (2) be held in the locked position by solely mechanical means. (b) Each motorcycle equipped with a parking brake shall have a configuration that enables a rider to be able to actuate the parking brake system while seated in the normal driving position.

S5.1.4 Two-wheeled motorcycles of categories 3-1 and 3-3. Each category 3-1 and 3-3 two-wheeled motorcycle shall be equipped with either two separate service brake systems, or a split service brake system, with at least one brake operating on the front wheel and at least one brake operating on the rear wheel.

S5.1.5 Three-wheeled motorcycles of category 3-4. Each category 3-4 motorcycle shall comply with the brake system requirements in S5.1.4. A brake on the asymmetric wheel (with respect to the longitudinal axis) is not required.

S6.1.1.1 High friction surface. A high friction surface is used for all dynamic brake tests excluding the ABS tests where a low-friction surface is specified. The high-friction surface test area is a clean, dry and level surface, with a gradient of ≤1 percent. The high-friction surface has a peak braking coefficient (PBC) of 1.02.

S6.1.1.2 Low-friction surface. A low-friction surface is used for ABS tests where a low-friction surface is specified. The low-friction surface test area is a clean and level surface, which may be wet or dry, with a gradient of ≤1 percent. The low-friction surface has a PBC of ≤0.50.

S6.1.1.3 Measurement of PBC. The PBC is measured using the ASTM F2493 standard reference test tire, in accordance with ASTM E1337-19, at a speed of 64 km/h (incorporated by reference; see § 571.5).

S6.1.1.4 Parking brake system tests. The specified test slope has a clean and dry surface that does not deform under the weight of the motorcycle.

S6.1.1.5 Test lane width. For two-wheeled motorcycles (motorcycle categories 3-1 and 3-3) the test lane width is 2.5 meters. For three-wheeled motorcycles (motorcycle categories 3-2, 3-4 and 3-5) the test lane width is 2.5 meters plus the vehicle width.

S6.1.2 Ambient temperature. The ambient temperature is between 4 °C and 45 °C.

Defined terms

The standard defines 32 terms in its definitions section; the first 12 are quoted here from the eCFR.

• Antilock brake system or ABS means a system which senses wheel slip and automatically modulates the pressure producing the braking forces at the wheel(s) to limit the degree of wheel slip.
• Baseline test means a stop or a series of stops carried out in order to confirm the performance of the brake prior to subjecting it to a further test such as the heating procedure or wet brake stop.
• Brake means those parts of the brake system where the forces opposing the movement of the motorcycle are developed.
• Brake system means the combination of parts consisting of the control, the brake, and the components that provide the functional link between the control and the brake, but excluding the engine, whose function it is to progressively reduce the speed of a moving motorcycle, bring it to a halt, and keep it stationary when halted.
• Category 3-1 motorcycle means a two-wheeled motorcycle with an engine cylinder capacity in the case of a thermic engine not exceeding 50 cubic centimeters (cm 3) and whatever the means of propulsion a maximum design speed not exceeding 50 kilometers per hour (km/h).
• Category 3-2 motorcycle means a three-wheeled motorcycle of any wheel arrangement with an engine cylinder capacity in the case of a thermic engine not exceeding 50 cm 3 and whatever the means of propulsion a maximum design speed not exceeding 50 km/h.
• Category 3-3 motorcycle means a two-wheeled motorcycle with an engine cylinder capacity in the case of a thermic engine exceeding 50 cm 3 or whatever the means of propulsion a maximum design speed exceeding 50 km/h.
• Category 3-4 motorcycle means a motorcycle manufactured with three wheels asymmetrically arranged in relation to the longitudinal median plane with an engine cylinder capacity in the case of a thermic engine exceeding 50 cm 3 or whatever the means of propulsion a maximum design speed exceeding 50 km/h. (This category definition is intended to include motorcycles with sidecars.)
• Category 3-5 motorcycle means a motorcycle manufactured with three wheels symmetrically arranged in relation to the longitudinal median plane with an engine cylinder capacity in the case of a thermic engine exceeding 50 cm 3 or whatever the means of propulsion a maximum design speed exceeding 50 km/h.
• (a) For motorcycle categories 3-1 and 3-3: a service brake system where at least two brakes on different wheels are actuated by the operation of a single control.
• (b) For motorcycle categories 3-2 and 3-5: a service brake system where the brakes on all wheels are actuated by the operation of a single control.
• (c) For motorcycle category 3-4: a service brake system where the brakes on at least the front and rear wheels are actuated by the operation of a single control. (If the rear wheel and the asymmetrical wheel are braked by the same brake system, this is regarded as the rear brake.)

Limits of this page

This page quotes the text of 49 CFR 571.122 as published in the eCFR, current through October 29, 2026. It omits tables, figures, cross-referenced test procedures in other parts, and the preambles and rulemaking history that explain the rule. It does not tell you whether a given vehicle, part or product complies, how to run a test, or what a manufacturer must certify. Compliance questions go to the manufacturer's engineers, qualified counsel or NHTSA. The eCFR is an editorial compilation, not the official legal edition of the Federal Register.

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 571.122, Standard No. 122; Motorcycle brake systems. (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR part 571, Federal Motor Vehicle Safety Standards (current through October 29, 2026) (read November 2, 2026)