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-   -   Can't get those cranks loose (https://www.bikeforums.net/bicycle-mechanics/206201-cant-get-those-cranks-loose.html)

purple hayes 06-26-06 07:32 AM

Can't get those cranks loose
 
I'm getting a popping noise from my cranks/bb when I stand to pedal.

I want to take off the cranks and bb for a clean and re-install, but I can't budge the bolts that hold the cranks on.

Any suggestions? I'd hate to take it to a shop for something so simple.

It's a Giant OCR Touring bike with Truvativ cranks if that matters.

KevinF 06-26-06 08:29 AM

Brace one of the pedals underneath or against a large heavy immobile object -- i.e., a wall or underneath a car. Position the wrench for proper leverage (i.e., straight up and down seems to work for me -- then you can pull on it while leaning backwards).

Dostoy 06-26-06 09:21 AM

If you can secure the cranks like Kevin suggested, slipping a piece of pipe over the end of the wrench to extend the handle length will give you the needed leverage.

Peek the Geek 06-26-06 12:18 PM

Rotate crank to 3 o'clock position.
Position wrench so that the handle sticks out at the 9 o'clock position.
Carefully stand on wrench with left foot and on crank with right foot.
Gently bounce up and down until bolt comes free.

(NOTE: Not responsible for any bodily harm this might cause if things go wrong.:D )

Old Hammer Boy 06-26-06 03:14 PM

Make sure you have removed any washers that may be in the way.

Peek the Geek 06-26-06 03:44 PM


Originally Posted by Old Hammer Boy
Make sure you have removed any washers that may be in the way.

If he can't get the bolts off, he hasn't gotten this far yet.

Mothra 06-26-06 04:01 PM

Use a real wrench for once! Those tiny 6" double-sided Park tools for crankarms isn't gonna give you enough leverage! Use an automotive 3/8" drive ratchet-wrench with 12" handle and it'll come off easily! Also use that size torque-wrench to re-install the crank-arm bolts.

Fredmertz51 06-26-06 04:49 PM

Good luck, I've got a good schwinn moab frame stripped except for the crankset in the garage because I couldn't get the bolts loose. Tried all kinds of cheater bars, took the bike to the LBS,they shrugged their shoulders, and finally used an impact wrench which stripped the flats inside the allen bolt. Burnt up $20 worth of carbon? drills trying to drill out the bolts, and am unable to even get a hacksaw blade between the crankset and the frame to saw off the spindle. Really liked the frame too.

Old Hammer Boy 06-26-06 08:58 PM


Originally Posted by Fredmertz51
Good luck, I've got a good schwinn moab frame stripped except for the crankset in the garage because I couldn't get the bolts loose. Tried all kinds of cheater bars, took the bike to the LBS,they shrugged their shoulders, and finally used an impact wrench which stripped the flats inside the allen bolt. Burnt up $20 worth of carbon? drills trying to drill out the bolts, and am unable to even get a hacksaw blade between the crankset and the frame to saw off the spindle. Really liked the frame too.

A bit brutal, but how about cutting off the crank arms and having a go at it with a Sawsall? It sounds like you don't have much to lose.

Old Hammer Boy 06-26-06 09:01 PM


Originally Posted by Peek the Geek
If he can't get the bolts off, he hasn't gotten this far yet.


Right you are. For some reason my mind was fixed on pulling the cranks. I've never had a problem with the bolts, but I use a good, long socket wrench for the task and alway grease the threads upon re-installation. I left a washer in one time and played hell pulling the crank. Kinda like standing on a board while trying to pick it up.

MudPie 06-26-06 09:04 PM

One word: leverage.

If you can take the pedals off, you can slip a large diameter pipe over the crank arm and use a socket (3/8" drive) with breaker bar - the longer the better. Wrap the crank arm in a towel/rag before slipping the pipe over it.

You also might want to drip some penetrating oil into the interface, in hopes of getting some into the threaded area.

I guarantee you'll be satisified when that bolt breaks free!

SD_Joe 06-27-06 08:39 PM


Originally Posted by Fredmertz51
Good luck, I've got a good schwinn moab frame stripped except for the crankset in the garage because I couldn't get the bolts loose. Tried all kinds of cheater bars, took the bike to the LBS,they shrugged their shoulders, and finally used an impact wrench which stripped the flats inside the allen bolt. Burnt up $20 worth of carbon? drills trying to drill out the bolts, and am unable to even get a hacksaw blade between the crankset and the frame to saw off the spindle. Really liked the frame too.

I had a similar problem with a Truvativ crank and rounded off the allen bolt. I ended up drilling it out with a nice fresh bit and using an easy out. Got the bit and easy out from Home depot for about $10. I ended up using a long Crescent wrench on the easy out and eventually got the bolt out. I could feel the easy out twisting through.

Mothra 06-27-06 10:54 PM


Originally Posted by SD_Joe
I had a similar problem with a Truvativ crank and rounded off the allen bolt. I ended up drilling it out with a nice fresh bit and using an easy out. Got the bit and easy out from Home depot for about $10. I ended up using a long Crescent wrench on the easy out and eventually got the bolt out. I could feel the easy out twisting through.

That's scary. If you had snapped off the EasyOut in the drilled-out bolt, you'd be in even bigger trouble! In which case, you can drill out the super-hard EasyOut with a masonry drill-bit, use lots of cutting oil... :)


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