What a coaster brake is
A coaster brake is a rear-wheel brake that you apply by pedaling backward instead of squeezing a hand lever. The braking parts are sealed inside the rear hub, so there are no cables, levers or pads visible on the outside of the wheel.
How coaster brakes work
Pedaling forward drives the bike as normal. When you stop pedaling, the bike coasts freely and your feet can stay still. Pushing the pedals backward, even a small amount, engages the brake inside the hub: internal parts expand against the hub shell and slow the wheel.
A small metal arm, called the brake arm, is clamped to the chainstay (the frame tube running back to the rear axle). It stops the brake mechanism from simply spinning with the wheel, so the braking force is transferred to the frame.
Where you find coaster brakes
- Children’s bikes, especially smaller ones, because pedaling backward is an easy action to learn.
- Beach cruisers and retro-style city bikes, where a clean look and low upkeep are priorities.
- Single-speed utility and rental bikes used mostly on flat ground.
Some bikes pair a coaster brake at the rear with a hand brake on the front wheel, which adds stopping power.
Advantages
- Very little maintenance. The mechanism is enclosed and protected from dirt and water, and there are no cables to stretch or pads to replace.
- Clean handlebars. With no rear lever or cable, there is less to snag or adjust.
- Reliable in poor weather. Because the brake is inside the hub, rain and mud do not affect it the way they can affect rim brakes.
- Intuitive for new riders. Many young children find it easier than coordinating a hand lever.
Disadvantages
- Limited stopping power. Braking is usually weaker than a good front hand brake, and it only acts on the rear wheel.
- No backpedaling. You cannot reposition the pedals by turning them backward, which makes it harder to set your foot for a start.
- Dependent on the chain. If the chain slips off (why a bike chain keeps coming off) or breaks (why bike chains break), the brake generally will not work, because it relies on the pedals and chain.
- Heat on long descents. Sustained braking can heat the hub, and these brakes are not well suited to prolonged steep downhills.
- Rear-wheel removal is more involved. The brake arm and hub make fixing a rear flat a bit more fiddly.
- Limited gearing options. They are mainly used on single-speed bikes, though some internal-gear hubs offer a coaster brake version.
Are coaster brakes good?
They are good for what they are designed for: simple, low-maintenance braking at low speeds on flat or gently rolling ground. They are generally not the best choice for hilly terrain, heavy loads, fast riding or any bike that needs strong, controllable stopping. For those uses, rim or disc brakes with hand levers give more power and control. See our comparison of bike brake types for the alternatives.
For children, opinions differ. Some parents like coaster brakes for young beginners, while others prefer teaching hand brakes early because they will need that skill on most bikes. The right choice can depend on the child’s age, hand strength and the bike’s size. A local bike shop can help you decide.
Basic care
Coaster brakes need little attention, but a few checks help:
- Make sure the brake arm clamp is tight and the arm is firmly attached to the frame.
- Keep the chain clean, lubricated and at the correct tension (see how to tighten a bike chain), since the brake depends on it.
- If the brake feels weak, grabs or makes unusual noises, have the hub inspected. Internal servicing is often best left to a shop.
Replacing a coaster brake or adding hand brakes
If you find a coaster brake too limiting, you can often add a front hand brake, provided the fork has suitable mounting points. Switching the rear wheel to a freewheel and hand brake setup usually means a new wheel or hub and compatible brakes. Check your frame and fork for compatibility first, and consider professional help.
How coaster brakes compare with other types
- V-brakes use two arms mounted on the frame or fork that pull rubber pads against the rim when a cable is pulled from a hand lever. They are generally stronger than a coaster brake and work on either wheel.
- Hydraulic disc brakes use fluid in a sealed hose to press pads against a rotor, and generally offer the most control. See how hydraulic bike brakes work.
- As a rough rule, the three main families are rim, disc and hub brakes, and the coaster brake belongs to the hub family.