FK Black Bump Rubber, Super Soft

This FK Bump Stop is 2-1/8" tall, 1/2" Internal diameter hole.

 

A bump rubber is used to keep the car from bottoming out and to add spring rate and therefore dynamic corner weight when the chassis travels far enough to get into the bump rubber. Generally, bump rubbers are used on the left rear shock.

It is used on winged racing in some situations to keep the car from bottoming out on the left rear on entry which will kill traction. However, because it also adds a progressive spring rate on the left rear can also loosen the car because it unloads the right rear on entry. See the Rethink Dirt paper in the Tech Department of the website for a more clear understanding.

A bump rubber can also be used on the left rear of a wingless car to add traction on corner exit. As the car squats on the left rear under acceleration, if set correctly, it will compress the bump rubber and add a lot of left rear weight, which can, i