stripped crank threads - help requested

Hmm, they're not completely stripped yet but it's on the cards I feel. I can no longer use the self extracting bolt cap on my 7700 cranks (non DS) as it just pops out as soon as I start to turn the bolt beneath it, I can use a crank puller screwed in firmly however I'm worried how long that will last. If there's anything that can be done to improve this situation I'm guessing it's easier with the cranks off the bike, hence a bit reluctant to put them back on currently.

Any suggestions?

Putting them on shouldn't cause a problem, and I find riding them gently with the bolt taken out will loosen them quite easily with no damage. Obviously not the best solution, but I don't think anyone has yet found a solution for stripped pedal threads, other than replacing the crank.

Thanks for the quick reply Foz, sorry it's not the pedal thread its the BB axle thread (if that's the correct term). I wouldn't be as concerned about the pedals, I just really don't fancy ending up with the crank stuck on the bike when I find out I need to service the BB next time.

Does the riding with the bolt out work there to you think? I guess you're answer that nobody's found a solution transfers to that part of the crank as well?

....this tool never fails for cranks with stripped threads every tool box should have one << http://www.ebay.co.uk/itm/75mm-Long-Jaw ... SwBLlVLSGy >>

Griff

Never seen one of those before, I'm guessing it pulls the crank from the outside pushing down on the axle?

Riddim,

You'll be fine riding them even tho the dustup threads are gone. They aren't whats holding the crank on. As long as the spindle threads are good you're fine.

BUT, there is no way to replace the threads in the crank. It is a 22 x 1.0 and I have not been able to find a HeliCoil kit in that size. I have the Bicycle Research tool to "tap" a crank. But it doesn't make threads. It just cleans them up. A HeliCoil is really needed.

The issue arises due to lack of grease and excess friction in a self extracting style bolt. I always make sure there is a bunch of grease to avoid this issue. At least you can get it off with an extractor. Just be careful.

As a last resort, a gear puller like mentioned above on ebay works and works super super well. Just make sure to add lube to the main screw on the puller. They are very fine threads and will die quickly due to friction. But since an Octalink is not very taped, you should be fine VS a square taper design.

Foz:
yes, there are HeliCoils for pedals. Expensive, but available. I have a 9/16" left and right kit I have used before. They work very very well and recommend everyone having HeliCoil kits handy for the common sizes on bikes. I love them. Expensive but well worth the investment.

What sort of bb axle is it? Splined or square taper?

Mark

He said it is a 7700 Dura Ace-that is an Octalink design.

@Salesguy - thanks, I wasn't worried that the crank would come loose when riding, it was more an issue of it getting stuck on the bb axle. I guess the tool above will solve that if it comes to it. Re greasing the bolt covers, thanks for the tip, didn't realise the importance of this. As you mention the octalink isn't tapered which I guess will go in my favour if the threads completely let out, I suspect it would probably tap off from the back with the bolts removed.

@Mkone - Octalink, which makes some crank pullers a bit awkward however guess it has the benefit of no taper

@Excel - thanks, another tool I'll probably need at some point, I'll need another shed soon

Thanks all for the above, I'm going to stop worrying and re-fit them now

Riddim:

The spindle isn't tapered, but the arm itself is. Very slightly, but it is. So a puller will be needed. DON"T hit the arm with a hammer or mallet. Too great a chance of messing up the arm or rings or frame. Use the gear puller if you do get into a bind.

As for the dust cap, make sure you grease the head of the bolt, the washer and the dust cap. lots of it. Can never have enough there. any metal on metal interface like that that can have friction, grease it. Extra will squeeze out. Just clean it and be happy you did it. Chance of this happening again is much much slimmer.