The SINZ Brake Adapters are designed specific to solve braking problems that exist on certain frame/wheel combinations. The most common problem is using 20x1-3/8" wheels on a Pro size frame (or a frame designed for 20x1.5-1.75" wheels. The taller 20x1-3/8" wheels cause most brakes to come short of reaching the rim for safe braking. The SINZ Brake Adapters eliminate that problem by extending the brakes enough to reach the rim.