Cantilever brakes, also known as cantis, are a type of rim brake designed for touring bikes and tandems. They were the brake of choice on the first mountain bikes because they were the most effective brakes available at that point in time.
Brake lever choice is less critical with cantilevers than with other types of brake, because the mechanical advantage of a canti can be altered, notably by varying the length of the transverse cable connecting the brake arms (the link wire or the straddle cable). The shorter the transverse cable, the lower the yoke, the higher the MA, and the greater the force exerted on the wheel (at the cost of less brake pad clearance). Sheldon Brown’s article on cantilevers has detail on adjusting MA on cantis.
The basics of mechanical advantage with cantilever brakes
Low mechanical advantage means the brake arms travel a long way but the force they exert on the rim is low. High mechanical advantage means the arms travel a short distance but exert lots of force. Setting up a cantilever brake involves finding the optimum MA.
Low MA = small force, long travel
High MA = large force, short travel
Variations in cantilever brake design
Cantilever brakes can be wide profile, mid-profile or low profile. ‘Profile’ simply refers to how far the brake stick out at the sides. Wide profile cantilever brakes are also known as frog leg cantis and are popular with touring cyclists, who need to cover many miles in a day. Mechanical advantage varies with profile.
Compatibility with brake levers
Most cantilever brakes are compatible with brake levers designed for caliper brakes. This means they will work with (most) brake levers made for drop bar road bikes.
Comparison with vee brakes
The Rodbikes website has an interesting evaluation of cantilever brakes versus vee brakes and disc brakes on loaded touring bikes. It explains that canti brake pads last longer than vee brake pads made of the same compound because they are thicker. On a loaded tourer, cantilever brakes are less likely to suffer from brake squeal than vee brakes, the article claims. It also points out the risks of brake fade and disc warp when disc brakes overheat, problems that can affect loaded touring bikes fitted with disc brakes but not those with rim brakes.
Paul Components is a notable manufacturer of after-market cantilever brakes.