Mechanical Brakes which can completely stop your kart in 18 feet are a required safety system. (1.13.3) while other style (band, Boden-cable disk) brakes have been common in the past, it's highly recommended that any new builds going forward use hydraulic disk brakes. Especially since your brake assembly does not count towards the cost of your vehicle on the BOM, (as is the case with all safety-exempt items) their usefulness should be prioritized.

Commercially produced Motorcycle hydraulic brake kits, which include a hydraulic reservoir on a hand lever, hydraulic tubing, fittings, a caliper set and pads, and the disk the calipers bite down on, can be purchased from the online retailer of your choice, even pre-filled with fluid, so as little engineering as possible is needed to install them.

Be aware: the forces the brake calipers apply to your frame are some of the most acute stresses your frame will be under while in normal operation. Weld or otherwise reinforce the section of your chassis which the brake calipers bolt to so that the act of braking doesn't break your brakes.

Most karts on the field today run with a single brake caliper and disk on the solid rear axle, and can regularly lock-up the axle completely with little braking force needed from the brake lever/handle.

Be especially aware: During the Qualifying event at every race weekend you will need to pass the brake test. (4.1.1.2) failing to stop after the end of your Hot Lap within 18 feet of the Timing and Scoring truss will result in a “scratch” and your lap time will not be counted. Karts that do not pass the brake test are not allowed to race.

Brake lights are recommended safety systems (required for night races) and are safety exempt from the BOM. the aforementioned hydraulic brake kits often have a NO electronic switch included in the brake lever which closes when the brake lever is depressed. If you already have this switch built into your brake lever, it's reasonably straightforward to wire up some red lamps on the rear of the kart to cut on through the switch.

(A low voltage buck converter/regulator which drives a myriad of low voltage electrical systems is not inherently BOM-exempt just because it also powers a taillight assembly, and does count on the BOM if it also provides regulated power to any non-exempt systems.)

These historic links are preserved here for posterity:

See Also: Brakes! A more technical discussion

• Lighter duty parts
• Heaver hydraulic brakes
• Disc Brake Calipers
• Hydraulic Conversion - Front
• 120mm Disk Brake Rotor