Bicycle Mechanics - Is it possible to retrofit a coaster brake to a rear wheel?

This will probably be a quick 'no' - but it's worth asking anyway. Just got a 48 spoke 20" wheel but realized when I got it that it didn't have a coaster brake. Is it possible to swap out the existing hub or does it require rebuilding the whole wheel? If it requires rebuilding what about turning this freewheel into a fixed wheel? I checked out Sheldon Brown's site but I wasn't totally sure if it was possible or not.

Thanks!

Firstly ... what are you fitting the wheel to? If it is a BMX or some frame that is designed to take a 20" wheel with 110mm spacing then I'd save your money and time and buy a wheel already set up with a coaster hub ... + I don't recall ever seeing a coaster hub with 48 spoke holes so a rebuild might be out of the question ... ?? correct me if such a thing exists. There are fixed cogs available ... if your thighs can take the strain.

So far as I know, the answer is no. You can't retrofit a coaster brake onto a regular freehub, 'cause the coaster brake mechanism is internal, so coaster hubs are made differently. But as Bike Nurse says, if you want a coaster brake wheel, you can probably get one for cheap. Shoot, if quality isn't an issue, buy a kid's one-speed from Salvation Army, steal the rear hub from that, get the rims and spokes of your choosing, and build the low-end coaster brake wheel of your dreams.

Cool - thanks guys!

I have a vintage Russian folding bike from the 50's and the rear wheel is in pretty bad shape (and my 260 pound frame isn't helping it much!). The wheels are 20" so it doesn't seem to be a problem swapping them out.

I actually found a 48 spoke rim with a coaster brake on ebay - it's on the way :) Hopefully I can sell the other rim (which seems to be in really good condition) or perhaps convert it to a fixed wheel. I didn't think about the spacing - hopefully it won't be a problem that a different sized nut couldn't fix :)

Could you point me in the direction of the fixed cog conversions? I've done some google searches but don't know if what I've come up with will do the job.

Thanks again!

Could you point me in the direction of the fixed cog conversions? I've done some google searches but don't know if what I've come up with will do the job.

Thanks again!
Remove the clutch spring and brake shoes from inside the coaster brake hub, then weld the driver into the hub.

How is this conversion, durability wise?

"swap out the existing hub "

Sounds impossible to me. Some Internally geared hubs have the brake in a separate unit. I guess there might be some heroic technique to mate a derailleur rear wheel with an internally geared hubs coaster brake. Please post pictures if you pull it off.