Rear cable hanger seat post fitting

colint

My frame doesn't have a rear hanger so have bought one of these

http://www.universalcycles.com/images/p ... l/6701.jpg

I assumed you just threaded the seat post bolt through the hanger to attach it, but there's an additional screw on the hanger (the black one). What's it for ?

Cheers

John.T

To adjust the angle of the bracket for cable alignment and to make sure it will not move when you pull the brakes on.