Hi everybody,

So I found this rusty bike on the street the other day being tossed away and was thinking of making it my beater bike. It was rusted pretty tight (been left out all winter looked like) but I got it apart and stripped it down to the frame, bb, and cranks. Took off the rust and was feeling pretty happy about it. The cranks were cottered and I got the non-chain ring side off just fine but on the other side I bent the screw. Aggh!

Well I figured I could just take off the bb on that side and slide the whole mess out and so took it to the bike co-op where they have a thin enough cone wrench to get in there. WD-40'd it real good both around the outside and from inside. I think I yanked on this thing for 30 minutes at least and it never even budged. Not one bit.

Anyways, anyone have an clues about how I might go about getting it off? Or is it just a bust? Easy come, easy go I guess but it's a nice enough (for being free) large frame and I'd quite like to fix it up. If nothing else, I guess it'll teach me to be more careful with cottered cranks!

Thanks for any help,

J

You're not gonna get the fixed cup out without a few swear words and a wrench the length of your leg. Plus it likely has left-hand threads, so you were probably tightening it (exceptions: Swiss and Italian BB's- find out what kind it is before trying to remove it). Most people leave it in there, just clean and re-grease it from the adjustable side. That being said, cotters are soft and easily drilled out if you can't hammer them out- usually it takes a single stiff blow on the top of the loosened nut to pop out the cotter. Or maybe your co-op has a cotter press. More than likely it will destroy the cotters; they'll need replacing anyway. If you use the hammer method, make sure to support the axle/crank on something so you don't dent the axle and cups with the ball bearings when you whale on it with the hammer- then you'd really need to take the cup out (to replace the ruined BB).

First, stop crapping around and get the right crank off. here's how.

Do this at the co-op where you have access to a repair stand, or a willing volunteers extra hands. If they don't have one bring a pair of vice-grip, a punch and a length of pipe or similar. The keys to hammering out a pin are to properly support the arm to concentrate the energy, and to deliver a bigger blow than it can absorb by deforming. Start off by sawing off the pent part of the pin flush to the arm.

On a repair stand, use a pipe about 3' long and lower the bike so the crank arm is resting on the pipe (other end on the steel base of the stand) with the pin in the hole. Make sure all is braced up solidly. Set the punch against the pin, and strike it with the hammer as if you wanted to blast it down the pipe, through the base and on it's way to China. If you don't trust yourself to deliver a serious blow with your other hand directly in the line of fire, use the vice-grip to hold the punch (don't use regular pliers, you'll sent the punch off flying endangering your neighbors).

If you don't have a repair stand, you can do the same, using a short piece of pipe securely braced in a bench vice, but you'll need someone to hold the bike.

In any case the thing to remember is that you intend to remove the pin in one shot, not with multiple hammer blows.

Once the right crank is out of the way, you'll have multiple options for removing the bottom bracket.

BTW- start on the left side which is 100% sure to have right hand threads.