Set Up A Bike’s Cantilever Wheel Rim Brake

Set Up A Bike’s Cantilever Wheel Rim Brake


Clean the threads on the inside of the bosses
and the matching threads on the cantilever brake bolts. If they’ve been used before, acetone is
the best substance to remove old thread-lock glue. Handle acetone with care it’s volatile and
flammable. The inside of the bosses need to ‘sticky’. Clean the outsides of the bosses. The outside of the bosses need to be ‘slippery’. Lightly grease the outside of the bosses. Don’t get grease the on threads inside the
bosses. Each arm has it’s own return spring. One end of the spring sticks out of the back
of the arm and locates in a plate at the base of the boss. If the boss has three holes make sure the
springs on each side are located in matching holes. The top hole gives a sharper return action. The bottom hole makes the cantilever brakes
easier to pull on, but in this position they return with less force. Mount the arms on the bosses with the springs
in matching holes. Carefully apply a small amount of thread lock
adhesive to the inside of the bosses and then screw in the bolts to lock the arms on the
frame. The bolts need to be as tight as possible
but still allow the arms to pivot. If the wheel is out of the bike, replace the
wheel. Mount the blocks symmetrically so both hit
the rims flat. Check for symmetry with your head on the bike’s
centre line. Some systems allow you to toe-in the cantilever
brake blocks. If the front of the shoe hits the rim slightly
sooner than the back the cantilever brakes may be less likely to squeal. Set-up the main cantilever brake cable. Thread the yoke onto the main cable and clamp
it in a position where the straddle wire will rest in the yoke angled roughly 45 degrees
above horizontal. Hook the nipple end of the straddle cable
into one arm. Run the straddle cable over the yoke and thread
it under the cable clamp. Pull the straddle cable through while holding
the cantilever brake arms in the ready position with the blocks close to the rim. Clamp the cable. One or both of the arms may have a small screw
to adjust the pre-load on the spring. Screwing in the balance screw makes the arm
it’s in more active. Unscrewing the balance screw makes the spring
work more gently. Adjust the screw – or screws – until both
arms move the same amount. Cut and cap the ends of the main cable and
the straddle cable leaving plenty of room for adjustment.