Pulling From The Center (rim brakes talk)

from Rookie’s keyboard,

Hello, friends

I am back with another post focusing on rim brakes.

This piece will shed light on center-pull and cantilevers (a.k.a. cantis).

Center-pulls are old-school rim brakes found on many retro bikes. Just like calipers, they attach to the frame and fork via bolts.

The brake cable pulls a straddle wire attached to the brake arms.

The brake arms pivot around two independent fulcrums and grab the rim. The friction between the brake shoes and the rim slows down the respective wheel.

Cantilever Brakes

Cantilever brakes are quite similar to center-pull brakes. They also have a straddle wire which pulls both arms. Therefore, cantilever brakes are essentially center-pull brakes themselves.

The difference is the length of the straddle wire and the design of the brake.

Unlike center pulls, the brake arms of cantilever brakes do not form an arch and extend outside of the bike’s profile.


The Nice Sides of Center Pulls

  • “Slim Fit”

Center-pulls have a slimmer profile and do not protrude outside of the bike’s frame or fork. This property has the following benefits:

a. You are less likely to come in contact with the brakes when getting on and off the bike.

    b. The brakes are more protected during a fall.

    • Retro Appeal

    CP brakes complement the look of old-school bikes.

    • Lower Chances of Fork Shuddering

    If you have rim brakes, and your fork is vibrating when stopping, the bike is suffering from fork shuddering.

    The explanation is as follows:

    The fork, the brake, and the brake cable hanger form a bow.

    The fork is the body of the bow whereas the brake and the cable hanger are the end points. The steel brake cable is the bowstring.

      During braking, the friction between the front wheel and the ground causes the front tire to “grab” the ground.

      The bike keeps moving forward due to inertia. And the fork has no choice but to bend backward.

      When the fork bends, it stretches the brake cable which in return closes the brake arms and triggers the same cycle.

      The fork keeps vibrating until the bike comes to a stop or you stop stopping. The more aggressive the braking, the more violent the vibrations are.

      This phenomenon is a million times more common for cantilever brakes with a brake cable hanger part of the headset due to the long distance between the brake and the hanger.

      The solution is to get a brake cable hanger mounted on the fork to shorten the bow.

      This is a Tektro cable hanger that mounts to the fork.

      Center-pull brakes are unlikely to create fork shuddering because the straddle cable carrier is closer to the brake cable hanger.

      This doesn’t mean that center-pull brakes are immune to fork shuddering, but the chance is much smaller.


      The Bad Sides of Center Pulling

      • Scarcity

      Center-pull brakes are close to extinct now. The reasons are:

      a. Side-pull brakes are lighter, simpler, and just as effective. Road bikes have no incentive to use center-pull brakes.

        b. Center-pull brakes offer greater tire clearance than side-pull brakes, but they can’t match the clearance of cantilevers and V-brakes.

        The low demand results in limited supply and a highly restricted choice.

        • Mud Accumulation

        The arch formed by the brake arms results in mud accumulation when riding off-road.

        You’re unlikely to see center-pull brakes on bicycles dedicated to diverse terrain.


        Cantis For The Win

        Overall, cantilevers are the winner because:

        • Tire Clearance

        Cantilevers are the rim brake model that offers the greatest tire clearance.

        • Reduced Mud Accumulation

        The extra tire clearance minimizes mud accumulation too. Also, the wider straddle wire has an easier time slicing through the mud thrown by the tire.

        Cantilevers are often seen on cyclocross bikes because of their extra tire clearance, reduced mud accumulation, and compatibility with drop bar brake shifters.

        • Some up-to-date models

        Cantilever brakes do not enjoy great popularity due to the rise of V-brakes and disc brakes.

        However, users can still find newer models designed for cyclocross racing.

        Having said that, it’s highly unlikely that the market share of cantilevers will grow.


        In conclusion

        Center-pull brakes make sense when:

        a. You want to preserve the original appearance of a retro road bike.

        b. You want to install wider tires and fenders while still relying on drop bar shifters.


        Cantis make sense when:

        a. You want to install maximally wide tires on a bike that uses drop bar shifters.


        Until next time,

        Rookie


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