Singlespeed & Fixed Gear - how to remove seized cog

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nowitsshowtime
06-21-09, 09:20 AM
I had a feeling it was going to be seized, there is some rust on the cog and wheel. Anyone have any recommendations how to get it off, or I can try the lbs.

I don't have a chainwhip but I've used a vice and wood and spun my old cogs off, or I'll wrap it in old chain and then put it in the wood and spin it off, no dice.

Ive tried PB blaster, which always worked great on seized car parts, and I've even tried using the torch extremely carefully. Anything else? I can try to soak it with pb blaster overnight.

Damn cog is making me roll around on 96gi on my spare bike >=l

JohnDThompson
06-21-09, 10:10 AM
Invest in a chain whip; it'll be worth it in the long run.
toezter
06-21-09, 10:13 AM
Worst that can happen is you'll strip your hub...thats how I ended up with a new wheelset :D

tgscordv6
06-21-09, 10:23 AM
reverse rotafix
The LT
06-21-09, 10:52 AM
stick the whole wheel in the freezer before trying to get the cog off (and get a chainwhip)...the thermal coefficient of expansion of aluminum is larger than that of steel so that means that when you heat it up the aluminum gets larger quicker than the steel making the interface tighter between the cog and hub but if you cool it down the reverse happens and the aluminum gets smaller faster than the steel making the interface between the two looser.

This is all irrelevant if the hub is steel
jjvw
06-21-09, 11:14 AM
reverse rotafix

Or do a better job with the vice and wood blocks.
dougland89
06-21-09, 11:21 AM
stop being a cheap ass and get a chainwhip, they're like $20 if that, i have never regretted owning one...
pazzmore
06-21-09, 11:35 AM
reverse rotafix

seriously... you don't need a chainwhip. use the rotofix method.

the only reason I might hesitate is if you had an aluminum frame, and even then you could just double up the padding around the bottom bracket (which is something missing from these instructions... wrap a cloth around that thing first).

ROTOFIX (http://204.73.203.34/fisso/eng/schpignone.htm)
jjvw
06-21-09, 11:45 AM
I'll add that Rotafix will give you more leverage than a standard chainwhip will. You have the full diameter of the wheel, against the full length of the chainstay.