Can I replace left side crank?

Mando Commando

Hi there,
My girlfriend's bike has a problem - the threads on the left side crank have sheared and the pedal won't stay in. It's a Dawes Hybrid Bicycle. I was wondering...

1 - Is there a handy fix for this? Tried that epoxy cement stuff to no avail.
2 - Are cranks standard? Can I buy one and fit it myself?

Any info appreciated, cheers.

SubLuminal

Do you mean the threads on the crank arm, or the threads on the bottom bracket? You can most likely replace the crank arm with one from Rothar (www.rothar.ie / www.tinyurl.com/rotharmap) - it's not a hard job at all especially if the crank arm is already coming off. If you need to replace the bottom bracket, that *is* a harder job, and you'll need special tools to do it, plus a new bottom bracket.

blorg

Yes, you can replace the left side and it is a lot cheaper to do than replacing the right side. Happy days. I have had to do it myself for the same issue you describe with the pedal threads. I don't think it would be economical to try fixing the threads once they are gone.

Cranks are standard but there are multiple standards so depends on what you have. Probably square taper. You could do it yourself but would need tools. A bike shop would not likely charge you very much for a new LH crank including installation.

Mando Commando

Thanks for replies folks,

To SubLiminal,

It's the threads where the pedal screws in. Cheers for that link to Rothar, it seems a good site.

To blorg,

Sounds like the local cycle shop might be the right way to go, seeing as the crank arms appear to be cheap by themselves on ebay etc. Got a mad quote from one shop the other day, but he led me to believe that left and right had to be replaced, which put me on the search! Perhaps one of the other shops will be more acomodating now that I'm armed with knoledge that it can be done and should be reasonably priced. Thanks

rob1891

The Bike Rack in Cabinteely might be able to install a thread repair coil (helicoil) in it if it is an aluminum crank (some very cheap ones are steel coated in plastic). The repair is typically stronger than the original threads.

You should give them a call if they are convinient. A lot of bike shops won't bother with this kind of work but they sorted me out recently for a very reasonable price. Unless you can get a crank arm for less than 20 euros, I am pretty sure it will be cheaper to repair.

blorg

rob1891 wrote: »

Unless you can get a crank arm for less than 20 euros, I am pretty sure it will be cheaper to repair.

I think the last left hand arm I had to replace cost a tenner, although that may have been one my LBS just had lying around. I have had to replace two in my time. In any case, they aren't expensive.

kumate_champ07

the only problem with finding a replacement left crank arm is that the q factor might be off balance, that is the distance between each pedal to the centre of the frame would be slightly different on each side,I dont think it would matter too much.

Mando Commando

rob1891 wrote: »

The Bike Rack in Cabinteely might be able to install a thread repair coil (helicoil) in it if it is an aluminum crank (some very cheap ones are steel coated in plastic). The repair is typically stronger than the original threads.

You should give them a call if they are convinient. A lot of bike shops won't bother with this kind of work but they sorted me out recently for a very reasonable price. Unless you can get a crank arm for less than 20 euros, I am pretty sure it will be cheaper to repair.

I'm in Sligo, so Bike Rack wouldn't suit me, although the crank seems to be aluminiun alright. Looked for a helicoil the other day, had no luck, and was led to epoxy cement.

I think blorg is right - I saw cranks for £6-10 on ebay, so a replacement job can't be too much...

kumate_champ07

I wouldnt trust the cement, helecoil insert is only worth the cost and expense if the cranks are very valuable