BMX Bike Brakes

Brakes…

Good brakes depend on a number of factors.  First, the brake itself.  A 990 u-brake is more powerful than a caliper brake, for example.  Next, the brake pads play an important role.  Good brake pads are the key.  Also, the rim is a factor.  Chrome rims will stop much better than brushed or another type of rim.  Minor factors include the type of lever you have, and how good your cable pulls.

Adjusting caliper brakes

If one of the arms tends to be closer to the rim than the other one, you can correct that by turning the nut in the back toward the side that sticks out more. This will turn your whole brake.

Brakes work best when they spring well, and when the pads are aligned.  If your brake doesn’t spring back too well, the spring nut may be too tight.  Try loosening it.

Adjusting U-brakes

The U-brake adjustment is really a three step process.  Before adjusting it, a good idea is to take out the tension in the brake by loosening the alen nuts on the brake until the spring comes loose.  You may need to hold the lower nut from moving with a wrench while you’re braking it free.

Now adjust the cable length.  You do this by loosening the straddle piece and sliding it up or down until you have just the right amount of movement in the brake (make sure that all adjustment screws are all the way in).  Then tighten it back up again.

Next, you need to align the brake pads.  You want it so that when the brake is pulled, the pad rests perfectly flat on the rim, and is in line with the rim.  This can be challenging if you are working on a Dia-Compe 990, because of the amount of movement the brake pad can go through.

Finally, after everything else is adjusted and tightened, it’s time to re-tension the brake.  Put your allen wrench into the spring nut, and your wrench into the tension nut.  To apply tension, turn the tension nut towards the rim (clockwise on the left side, counter-clockwise on the right).  When you have the right amount of tension, tighten the spring nut, and do the other side.  Don’t put too much tension in the brake, just enough  for the brake to work. If you tighten it too much your spring can break.

If your cable doesn’t slide right…

If your cable doesn’t slide right, try dripping some Teflon lubricant into it.  If that doesn’t work, you may need a new cable.  I like to drip Teflon into new cables, too;  it makes them work better.