Completely unremoveable cog
 

I built up a Paul set about a month ago and used a surly cog for about 2 weeks. Completely clean threads, greased, chainwhipped on, not rotafixed. Trying to remove this thing I encountered:

4 broken sections of chain on a chainwhip
1 bent chainwhip handle
1 broken allen key attempting to use a chain section in a vice grip with an allen key on the opposite end
1 bruised girl in the shop watching
4 different guys with no success
1 hour of WD40 soaking in the threads
1 broken heart full of dissapointment


Any possible ideas? I've had an EAI cog and new chainring ready to update my drivetrain. I have also encountered some pretty ugly threads after taking off the lockring so I'm a little scared at what I'll find if this thing ever does come off. Maybe I'll wait until winter so the metal shrinks.

Have you tried rotafixing it off?

I don't see rotafix in that list.
if that fails bench vise

wrap an old chain around the cog
clamp the chain ends in a vice
turn the entire wheel

It's always winter in your freezer, maybe give that a try.

Also it's always sunny at the end of a lit blow torch, maybe you can warm up the cog a little. Really though if what dutret and lyledriver suggest doesnt work i'll eat my hat.

It might be cross threaded. When you put the cog on, did it spin easy or did it require a lot of force. If you forced it on it is probably ****ed.

If you put it on OK I would suggest removing the lockring and putting it back on the bike. Do a few intense leg locks with as much weight as you can put on the pedals and the back wheel. It may take seveeral of these so don't give up too quickly. If this doesn't remove it take it to a shop.

loosen the lugbolts a little and roll the car back and forth..

oops wrong forum.

Tried that with two guys on it, that's how the allen key broke.

I must ride like a monster!

I'm confused. where does the allen key come in?

edit.. OH, you said vice grip.
I'm talking about a bench vice!

I haven't tried rota fixing off, I may give that a try.

I hope the threads arent cross threaded, I didn't really hulk it on there. I'll try the rota off, but if worst comes to worse I may just cut the thing off.

Unfortunately for you, it sounds like you rode it so hard it went through a state of metallurgy fushigation in which the two metals have fused together to form aluminprioxitanium.

I wouldn't mess with it. I heard that if you break the bond, it could explode resulting in the injuries of thousands.

Yeah, bench vise. The allen key was through the chain to try and prevent it from slipping, but slip it did.

COSMIC! Now if I could figure out how to turn lead into gold and water into microbrews!

rotafixing with two people is only slightly weaker then the bench vise method and worlds better then a chain whip or visegrip.

I took it to the shop which is where all this madness took place. The mechanic there is notorious for being able to untighten anything. Little did he know...

Here's a last-ditch idea if nothing else works. Using a dremel tool with a cutoff wheel (actually you'll probably burn through several wheels) cut inwards towards the hub threads as close to the hub as you can get without damaging the hub. A hammer and a large chisel should crack the last little bit and you should then be able to spin the cog off. if not do the same thing 180º around the cog, and it will come off in 2 pieces.

Bummer. I'm considering cutting two faces into the cog and placing that in the vise just to get this thing off.

Have you tried yelling at it ? it works for me sometimes..

I think that's how I stripped my crank when trying to remove the pedal...I would suggest against using a torch. The aluminum becomes weaker far faster than it or the steel expands.

Oh yeah, that's how I got my last cog off and it worked like a charm. No go this time.

I don't think I'll mess with the torch. Placing undue heat near any of my parts scares me if the bikes already built.

easy, just take the lockring off first.

just rota fix that **** off already

if the hub is Al and the cog steel then don't heat it as it will only make things tighter. Al has a higher coefficient of thermal expansion than steel so cooling it down would be the way to go if you are going to attempt this

exactly.....takes just 2 seconds.