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I recently came across a mid-1980s Shogun bike with a Tange 900 lugged frame. I began to remove the components when I came across a seized drive-side crank arm. I cannot separate the crank form the bottom bracket. I intend to reassemble, relube and have the bike available for my daughter. What can I do to remove the crank?
 

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I'm assuming that you have a crank puller?

If not, stop now, before you destroy the crankset. Which you WILL DO.

If so, here are a couple of thoughts:

If you've got good threads for the puller to go into, maybe putting a cheater pipe on the handle might help. That thin flat handle can hurt, and it sometimes takes a good, hard push to get them moving. Don't run out and put a 6-foot extension on it, but if the puller and the crankarm are nice and tightly threaded together, you should be able to exert some pretty serious force without damaging anything. Once it starts turning, you can discard the extension. We're looking for the application of steady, increasing pressure to break the crankarm free. Hammers, jumping on the tool, these are all bad thoughts.

It almost sounds like the crank was ridden loose, and then overtightened to keep it from slipping again. I've seen that many times. Usually (OK, every time I know of) the crankarm is deformed enough by this that it'll never be tight again. If it's toast, Chuck's Bikes has 105s and Ultegras (same crank, different rings) for under 80 bucks.

--Shannon
 

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Master Bike Mechanic
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If you don't have good threads to work with though there are a few things you can do. If you don't have one, a pickling fork is what I think its called, it's normally used for seperating ball joints on cars but it works fine for cranks too, but the drawback is it will destroy the crank arm.

The other thing you can do if you don't want to buy a new tool is remove the non-drive side crank and cup, put the bolt/nut partially on the bb spindle and whack it with a ball point hammer or use a rod placed against the bolt and use a normal hammer. You'll have to use a lot of force on the hammer and the remains of the spindle will go flying. I say remains becuse it's likely to break at the nut/bolt.

Either of these methods will damage one or the other, but with hammer and bolt method all you have to do is replace the BB with a $30 BB UN-53 sealed cartridge unit.
 

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Ok, this is obvious, but I have seen it happen. Make sure the crank bolt washer is not stuck inside the arm before you put the crank puller in. This will act like a seized arm. Any force used on the puller will just break stuff.
 
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