how to get a cog off

[thereisnogod]

hello, this is my first post and i hope an easy one to answer/i`m having trouble getting a 12 tooth cog off my wheel/ i`ve chainwhipped the shit out of it, i`ve tried liquid wrench and i`m having no luck/ i`ve heard using a pipe in combination with the chainwhip works sometimes but i dont want to break the chainwhip(its not mine)

[giventofly]

Freewheels and cogs on trials bikes become threaded on with the Fury Of God.
You will most likelly have to cut it.

Use a Dremel and a cut-off wheel, and cut into the cog in a 3 piece pie shape (like a mercedes logo) and then use a screwdriver and a hammer to chisel it off

Be careful not to go too far into the threads, or you'll ruin your hub Cut a little bit at a time, keeping watch for when the metal you're cutting changes color/texture. That's how you know that your're through the steel of the cog, and into the aluminum of the hub.

[Elan]

im guessing god felt like you deserved to not get it off :dunno:

just use the pipe ans stop being a pussy.

[xxxfr]

im guessing god felt like you deserved to not get it off :dunno:

just use the pipe ans stop being a pussy.
yeah, more leverage, ive never stripped a cog out using a chain whip, broke the whip, but hey, have at it, 10 foot pipe should do it ;)

[trauma100]

I will usually start off with Dinner (only if it's worth my time) and then go right into getting the cog as drunk as possible..then back to my place...more alcohol... maybe some Barry White or sex pistols...whatever fit's ..........then start off slow and work it into a greasy froth by licking the threads then tounging betwwen it's teath right at the base...give it the wrong phone # then tell it you have to work early and you had a great time...and show it the door.. your results may vary

[Don Coyote]

I've had good luck wrapping old chain around the cog to protect it, then clamping the chain/cog in a vise, and unscrew by putting massive torque on the wheel.

There's such a thing as an actual cog vise, if your lbs is really well tooled.

[tomacropod]

I don't think there's any reason to remove a cog which still has life in it. I generally just cut almost all the way through and then use a punch to bang it off - this generally breaks the cog at the point you've cut and it just unscrews then.

- Joel

[Don Coyote]

Yeah, if you want to change gear ratios it's better to buy a whole new wheel.;)

[airfruit]

what I did was I stuck some other cog on the freehub body took 2 chainwhips, put one on each cog and than torque them in opposite directions. did the trick

[RyanL]

the cog gets torqued clockwise so you need to tap the cog counter clockwise



usie a chain wip on another cog than the one you are going to tap then tap the stuck cog CCW



sry for typos contatacts aren't in so i can't see what i'm typing

[airmj]

what I did was I stuck some other cog on the freehub body took 2 chainwhips, put one on each cog and than torque them in opposite directions. did the trick
yes this is the easiest method.

[tomacropod]

for freehubs yes, I think this is a threaded hub.

- Joel

[airfruit]

errr, like a freewheel? cuz if its just one of those shimano threaded hub with a threaded cassette, don't u just use one of those funny threaded hub tool and a vise? and just grab ur wheel and turn it like mad to get it off. no chain whip needed because the tool locks on the part of the cassette body that doesn't even turn... if there's need to chain whip, then its a freehub body...? or he doesn't have a vise... I could be wrong tho.

[Little Android Man]

Dan (thereisnogod) bought my old FFW stuff to replace his stock monty setup, but he cant get t he cog off my old tryall wheel that is pretty much destroyed, so he needs it in one piece because he doesnt have dollars for a new one. so are there any more suggestions on how to get it off without ruining it?

[Don Coyote]

Use either a spray freeze agent (freon etc) or put it in the freezer overnight to contract hub and cog, then with a torch heat just the cog and quickly use the whip again.

[jmkimmel]

Use either a spray freeze agent (freon etc) or put it in the freezer overnight to contract hub and cog, then with a torch heat just the cog and quickly use the whip again.
any of y'all familiar with the coefficients of thermal expansion, or the thermal conductivity of alu vs. steel? If you do, this'll make sense: I wouldn't bother with torching the steel, cause ALU absorbs heat so fast. Also, freezing could make a little bit of a difference cause the alu will shrink more than the steel will, but it's probably gonna be negligible. Use a big-ass cheater bar and have a friend tap it with a hammer while you pull as hard as possible.