How to disable a coaster brake on a kids bike

There is no setting to turn off. A coaster brake is built into the rear hub, so disabling it means replacing the hub or swapping in a freewheel rear wheel — a bike-shop job, not a driveway one. On a cheap bike the wheel swap often costs a sizeable share of what the bike cost, which is why most parents who want a freewheel are better off buying a bike that already has one.

Why the bike has one in the first place

It is usually not a styling decision. The federal bicycle regulation at 16 CFR 1512.5 requires that bicycles be equipped with front- and rear-wheel brakes or rear-wheel brakes only, and it requires a footbrake on sidewalk bicycles with a seat height of 560 mm (22 inches) or greater. It also bars sidewalk bicycles from using handbrakes as their only braking system.

In practice that means small kids bikes sold in the United States very often arrive with a coaster brake fitted whether the manufacturer wanted it or not. woom says exactly this about the GO 2: the rear coaster brake ships as a CPSC requirement, alongside the two hand brakes woom actually designed the bike around.

What actually happens when a shop disables one

None of this is exotic, but all of it is labour, and a replacement 16 or 20 inch freewheel wheel is not cheap relative to a bike that cost under a hundred dollars.

The things people try that do not work

Over-tightening the brake arm clamp. Does nothing to the mechanism and can crush a thin chainstay.

Removing the brake arm but leaving the hub. Worse than leaving it alone: the whole brake assembly can then rotate inside the hub, which turns a working brake into an unpredictable one.

Packing the hub with grease. Makes the brake drag and slip intermittently rather than disabling it, and a brake that sometimes works is more dangerous than one that always does.

If the symptom you are actually chasing is a bike that is hard to pedal rather than a brake you dislike, a dragging coaster is a common cause and it is usually adjustable. That is covered on kids bike pedals hard to push.

When disabling it is the right call anyway

There are two genuine cases. The first is a child who has come off a balance bike and keeps stopping by stamping backwards on the pedals, which prevents them from getting the pedal into the start position. The second is a child learning on a bike that also has a proper hand brake, where the coaster is actively fighting the lever habit you are trying to build.

In both cases, before you pay a shop, check whether the bike has hand brakes at all and whether it is small enough to fall under the sidewalk-bicycle footbrake rule. If the coaster is doing legally required work, the answer is a different bike rather than a modified one.

The cheaper route: buy the freewheel

Three bikes in this registry are worth knowing about if a freewheel is what you actually want. The woom GO 3 runs two independently operated mini V-brakes at 16 inch. The Retrospec Koda 20 specifies a reach-adjustable hand V-brake and no coaster at all, which is unusual at its price. The Prevelo Alpha Two runs dual hand brakes at 16 inch on a 12.1 lb frame.

Across a used 16-inch bike plus a wheel swap plus labour, you are often close to the price of one of those, with a lighter bike at the end of it. The full list is on best kids bikes with hand brakes, and the case for each brake type is on coaster brakes vs hand brakes.

How to tell what brake your bike actually has

What to do instead if the problem is starting off

The complaint behind most of these searches is not really the brake. It is that the child cannot get the pedal into the starting position because back-pedalling engages the brake, so every start becomes a scramble. That is solvable without touching the hub.

Teach the forward-rotation start: with one foot on the ground, nudge the bike forwards a few inches so the leading pedal rises to the two-o'clock position, then push down on it. It takes about ten minutes to learn and it works on every bike, coaster or not. If the pedals themselves feel heavy rather than awkward, the cause is usually a dragging brake or a dry bottom bracket rather than the child.