Removing coaster-brake hub - what tool?
 

Hi!

does anyone know what tool I need to remove this BMX freewheel (see pic)? it has like three small "places" where the notches of the removal tool should go, as far as I can see.

I cannot seem to find it in the Park Tool range of freewheel removers.

thanks!

Maybe it's the pic or my eyes, but that looks a lot like the sprocket on a coaster brake hub. Sure this is a freewheel?

That is the driver/sprocket from a coaster-brake hub, else a coaster hub that was sabotaged into a single-speed hub.

A circlip rests in the groove visible behind the cutouts; the sprocket can be removed by inserting a pick/small flat-blade screwdriver underneath the circlip, by using the bottom of one of the cutouts.

The actual driver is, itself, held on by the hub cones.

Hi, I have checked and although the bike looks like a bmx it has in fact a coaster-brake hub.

Which poses the next question, is the coaster brake on the other side broken? (see pic)

I have also cleaned up the hub and took some better pics.

wschruba, thanks for this. I am not sure I have understood. How would the sprocket come out once I take out the circlip? Wouldn't the lockring still be there to hold the sprocket?

No. What you are seeing is not a lockring, but rather, the protruding body of the driver assembly. The extra length is necessary to provide a place for the circlip/snap ring to sit

http://www.parktool.com/assets/img/r.../coaster11.jpg

(image from Park Tools)

You need something like this to engage the three notches:
https://www.amazon.com/Park-Tool-HCW.../dp/B000C17KRI
and a chain whip or equivalent to engage the sprocket.

OK, I have now found this tutorial and will follow those instruction.

Thanks for opening my eyes :)

if anyone has some tips or tricks about this, please feel free to drop them here.

Coaster Hub Overhaul (Pedal Brake Hub) | Park Tool

Many thanks again, wschruba. I have found the same pic/page you posted.

Be careful that it does not fly out and hit you in the face when it pops loose; a gloved hand, or a shop towel draped over the cog should catch it.

Sprocket is held on by the circlip and notches on the cog engage the driver - no lock ring, sprocket pops right off. Yes, your brake reaction arm is broken, actually looks like it was sawed off.

A couple things from the pics you posted:

-That doesn't look like a Bendix hub, so it's probably a Shimano/KT/some derivation thereof. You can technically buy parts, but it's cheaper to simply buy a whole new hub, and cannibalize what you need from it (like the reaction arm). A shot of the internals, as well as the socket on what is left of the reaction arm, will fairly easily identify the hub (since most CB hubs place the brand on the reaction arm, and yours is mostly missing).

-It was fairly common 15-20 years ago (and I'm sure earlier) to convert a coaster brake into a single speed. It is crude, and creates a very poor performance freewheel. Most coaster brakes need you to rotate the pedals 1/3-1/2 of the way around to engage the driver, and they must 'catch up' to the wheel before they can drive (indeed, as does everything else, albeit with a faster engagement). It really would behoove you to replace the reaction arm, since it will at least function all the way like a coaster brake, rather than a poor imitation of a freewheel.

-You appear to have at least one broken spoke. If you repair the coaster brake, it is imperative that you replace any broken spokes, as the brake relies totally on the spokes to transfer braking power from the hub, to the rim/tire. Also note, rusty spokes that are pressed into service do not last long, so replacing all of them might be in order, as well. Unless there is some sentimental attachment/learning opportunity here, you may do better to simply replace the whole wheel with a new, pre-built unit.

Yes, i got that "bmx" for free from someone who was going to throw it away.. probably his kid saw off the brake arm to make it look cooler. Not sure if it is worth to buy a new hub as the bike itself is quite rusty and a cheap model anyway. My intention is to give it away to someone but let's see how it feels as a single speed.

I hear you about the spokes. Tjere are actually four broken ones and that was the reason i wanted to remove the sprocket.

Thanks again for your help.

Just looking at the general condition of the hub & spokes from your pics, I'd be very suspect of the internals.
On your 1st pic, I don't know if it's camera angle or not, but the axle looks non concentric to the hub.
If it is, the bearings are probably garbage and maybe the cones/races etc.

Sometimes "free" just means you end up disposing of someones junk.