Crank Replacement, Not Square!

sxsniper

Hi All,

I've just dug my old GT Aggressor out the garden, and the snow has wrecked it - Mega Rust, never seen so much rust in my life.
I've had to replace EVERYTHING. The frame seems 100% ok though.

The crank is the last thing left because I'm totally baffled by it.
It looks like it's just a normal bolt, like a spanner o socket wrench would take off. But it won't budge. I can probably make it budge, but this isn't really the point. To get a replacement. What should I be looking for, I'm assuming it has to be a certain type.

I know very little about bikes. I can repair anything once I've seen it in pieces. But I Can't get it apart to know what to buy, and dont want to break it off until I know I have the right part.

Im hopeing to buy it off ebay or from chain reactions. Any ideas or suggestions? I've only seen square crank bolts before!

nicklouse

what is the crank? names? part numbers?

have a read
http://www.parktool.com/blog/repair-hel ... nk-service

sxsniper

No idea. I was hopeing some guru could figure it out from my vague description.

I think its a Cartridge sealed bottom bracket.... but I bought it in 2002. Im looking at the 2010 models that say its Cartridge sealed.

Sound right. I think im just going to saw it off and dismantle it, take a picture, and ask you guys what I should buy.

It's so rusted you cant read anything on it.

Nice site too, but I cant see anything that looks similar to what im looking at.

nicklouse

with the info you have given it could be anything. is it even the original or the one speced?

pics of it as is will give us a clue.

or read the link i gave as it covers all crank and BB fittings.

sxsniper

Yeah its the original.
I'll saw it up tomorrow.

It's in such poor condition I could prob smash it off with a hammer :P

nicklouse

sxsniper wrote:

Yeah its the original.
I'll saw it up tomorrow.

It's in such poor condition I could prob smash it off with a hammer :P

unlikely.

sxsniper

No it isnt, the front forks snapped off just from rolling it in to a wall.

The chain snapped just from standing on it.
It's wasn't just any snow, it was acid snow.

You are underestimating the corrosion, and the similarity I have to king kong.

besides, I'm always winning against the odds - Bi-winning

DirtMonkee

haha, acid snow!

By sawing it off I'm asumming you mean sawing through the bottom bracket axel?

The old GT agressors were square taper cartridge brackets which should come off with a 14mm socket being soaked in gt85 for a while! If you saw it off your next problem is going to be removing the bottom bracket itself unless you saw the crank off and drill the bolt out....who knows.

If you do mange to get the bolt off you acid snow means you will probably need a crank extractor to get crank off.

Deputy Dawg

For the price of replacing the forks & drive chain you could most likely get a new bike.

sxsniper

I got the forks for free, and the drive train off an old bike.

Maths already done, cheaper to repair than to buy a new bike.

I hit it with the closest tool, a sledge hammer, the pedal stalk broke off so I picked up the next closest tool, a pick-axe and smashed the cartridge out. Got a new one it's all working fine.

Nice one.

MountainMonster

Hopefully you havn't damaged the threads inside the BB or anything, since it seems you know nothing about bikes.

DirtMonkee

I smell a halfords mechanic....