Installing a crank that already has stripped removal threads.
 

I bet its happened to a lot of us, at least once, spinning the removal tool thinking everything is hunky dorry and then seeing that it is in fact just shaving the threads.

Well, it happened to me at least, some time ago, and I just used another crank to replace it after I go it off with a steering wheel remover. Now i am putting together a fastish utility bike and was thinking about using that crankset. Its ok exept for the threads.

Do you just trash them? is there a trick to make them removable again for service?

You might be able to heli-coil it; I don't know about the availability of that size and threading.

Maybe just use a good quality cartridge bottom bracket that won't need service for a really long time? You'd have to remove it with a pickle fork again some day. But, you got it off that way once without damage. :-D

there is a repair kit that allows for oversize threads to be cut, then a bigger remover must be used...also pretty expensive so only for some crank of real value.
There's a simple technique of just riding the bike with crank bolts removed in a safe flat place (empty parking lot) until you feel the cranks go loose and wobbly...works about 80% of the time, but the spindle hole will probably be toast afterward.

What about using a small crank puller. They come in 2, 3 & 4 arm configurations. They are not expensive either. Just put something in front of the spindle bolt hole so you won't bung up the threads.

I've trashed one or two. I am willing to go with a non-match arm in a lot of cases, so YMMV. On at least one of there were lots of dent marks on the back. If you can find a wide blade crow bar that might fit. Auto repair tools?

You can buy a traditional puller (made for working on cars). I picked one up at a garage sale. I would not sell a bike with stripped crank threads, but I would probably use it on a utility bike as you describe.

Gear puller.

Not as handy or slick as a threaded crank-pulling tool but it gets the job done.

I was also going to suggest a gear puller but I have never used one. I would expect them to mark up the crans a bit and perhaps be a bit hard on the teeth. You might want to remove the chainrings prior to using the tool. If it were me, once the crank is trashed I would only consider using it on a beater bike where any extra marks are just added charm.

You're not alone, I did the very same thing last weekend, in a rush and thought 5 or 6 turns in with the crank tool would be ok, I wind away and out it pops wrapped in aluminium :(

The riding the bike until the cranks wobble loose sounds like a good backup plan.

Hmmm, I've got a Suntour Sprint crank with a stripped NDS removal thread. Maybe I'll use it on something after all? I was about to toss it.

-Collin-

Thanks for all the replies. sounds like I wont be to off the mark using the crank on a beater/utility bike. it will have a cheap cartridge bb, and I will just use it till it dies. Then worry about that when it comes. I have used the gear puller lots of times.

As a strong believer in brute strength and ignorance there are no real worrys about getting it off. I just wondered about options and what others do.

Drill chuck removal wedges work great.... http://www.jacobschuck.com/drill-chuck-install.asp

Hah, I wondered what those things were for...now I know, and it all makes sense. Thanks for solving one of life's little mysteries.

Especially with a cheap cartridge BB, if all else fails you can just use a hack saw on the spindle to get it off when the BB wears out.

Thanks guys! My extractor wouldn't thread into the non-drive side of a Peugeot's crank this morning and the threads stripped out. The first time this happened I had left the washer in the crank - this time I checked.
I'll let you know how the gear puller works.

Another fumble is not screwing the center-pin back in the extractor before threading it into the crank This gives a "false bottom" that lets one believe they have threaded it in enough but it will strip out.

The other day I almost forgot to unscrew the bolt in a crank before threading in the extractor. THAT wouldn't have worked so well!