There are few more frightening experiences when riding a motorcycle than to have the throttle stick open or the brakes not work. Eyes out on stalks, white knuckles and other bodily responses are the order of the day for either of these problems.

When motorcycle manufacturers began to fit rotors on motorcycles in the 60s and 70s, they left a lot to be desired for their stopping ability. These early systems often required very heavy lever or pedal pressures.

And if it rained? It was not uncommon to see people putting their feet down (either to aid braking or to get ready for the inevitable)!

Cross-Drilling

Many fixes were tried including cross-drilling. Although this helped to a certain extent with cooling, if the drilling was uneven or badly engineered, the rotors would warp or crack. The pads would also tend to wear out faster with a drilled rotor.

Although drilling rotors will often make a classic motorcycle's braking system look period correct, the owner must consider the safety implications if the bike is to be ridden on a regular basis. Fitting current pads in the place of the OEM part is the best option for improved braking.

Further reading:

How to Bleed Motorcycle Brakes