Coaster Brake to Freehub

Eureka! Here is an easy way to turn a coaster brake hub into a free hub!

Coaster brakes are a pain when trying to teach someone to ride a bike. Hand brakes are much better because then it is easy to turn a kids bike into a balance bike by removing the pedals and still allowing kids to stop their bike. With the pedals on it is better to allow new bicyclists to pedal backwards without causing a brake to engage. Coaster brakes make it harder for kids to learn, are not as effective as hand brakes, tend to cause more falls, and are also dangerous on bigger hills because they can overheat and fail. Alas the US Consumer Product Safety Commission requires coaster brakes for kids bikes -- it should instead just require all bikes to have effective brakes rather than stipulating the type of brake.

Disabling a coaster brake hub so it is a free hub (no braking action) is pretty easy for just about anyone (and super easy for anyone who knows how to use a cone wrench). Warning: there is a lot of grease inside a coaster brake hub!

Before or as part of disabling the rear coaster brake, make sure you have or add functional hand operated brakes (or at least a rear brake) to the bike with hand levers that work for your rider. Adding hand brakes may take some research to find brake levers that are good for kids as well as caliper rim brakes that work with your particular brake.

Tools:

1. Philips head screwdriver

2. Adjustable wrench (large 15mm and 17mm box wrenches are also helpful)

3. 15mm cone wrench

4. Needle nose pliers or diagonal cutters

Directions to disable your coaster brake and turn it into a freehub:

1. Disconnect the coaster brake arm using an adjustable wrench and screw driver. Keep the screw and clamp as you will need to reattach the coaster brake arm even though it will not be used for braking after this procedure.

2. Unscrew the axle nuts, take the chain off the rear cog, and remove rear wheel from bike. A large 15mm wrench or pedal wrench may help to unscrew stubborn axle nuts.

3. From the rear cog side take off the axle nut, cone lock nut (usually 17mm), & cone (usually 15mm cone wrench). Keep the coaster brake arm side assembled.

4. Using just your hand, untwist the right rear cog and set aside.

5. Carefully pull out the inner gear assembly by holding onto the still attached coaster brake side of the axle and pulling it out of the wheel hub.

6. Try to keep the bearings that are in bearing retainer clips in place by being gentle, if they fall out just remember to put them back in their correct locations and orientations when you reassemble the hub.

7. Remove and recycle the 2 loose curved pieces that should be stuck with grease to the outside of the inner cylinder from inside the coaster brake hub (these are the internal “brake pads”). They may just fall off as you pull out the inner gear assembly.

8. Pull the inner cylinder assembly off the axle attached to the coaster brake arm (it will be covered with thick grease).

9. Bend back or snip off the 2 thin prongs at one end of the inner cylinder spring assembly that pointed toward the coaster brake arm (snipping off is easiest to do with the cylinder removed from the axle).

10. Put the inner cylinder assembly back on the axle with the end that had the prongs on the same side as the coaster brake arm.

11. Reassemble hub (without the 2 loose curved pieces) adjusting the bearing cones and cone locknut as needed to turn smoothly without binding (easiest to do using cone wrenches).

12. Remount the rear wheel and finger tighten the axle nuts with the chain remounted on the rear cog. 

13. Reattach the coaster brake arm to the chain stay even though it is no longer needed for braking action (the coaster brake arm remains a useful spacer as part of the hub assembly). Fully tighten the axle nuts.

14. Verify your hand brake(s) are properly adjusted and working.

Voila! You can now pedal forward as usual as well as pedal backwards without worrying about any braking action!

The best video I have seen of how to do this is at https://www.youtube.com/watch?v=uI11KXFQPno. They bent the 2 prongs out of the way but I found it easy to snip them off with diagonal cutters. Googling “coaster brake to freehub” will locate other videos and instructions as well.

See also https://www.twowheelingtots.com/coaster-brake-vs-hand-brakes/

Enjoy!