Bicycle Mechanics - crank has kicked the bucket

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : crank has kicked the bucket

smelly
06-08-03, 11:03 PM
5 years ago when I bought the bike I put on these new pedals, I only threaded them in half way by hand(seeing as how I was so exsited), when I started to pedal half the threads connecting the pedal to the crank(on the left side) were yanked out, and all I had left were 4 or 5 threads left to hold in the pedal. Well after years of riding the threads on the other side are starting to give way. Can new threads be machined in? What can I do to save my crank? BTW, It's made if alloy!

mechBgon
06-08-03, 11:39 PM
A well-equipped shop might have an Eldi thread-replacement kit and be able to salvage your crankarm. The special reamer/tap unit reams the pedal hole to a larger size, then threads it, and a threaded bushing is threaded into the hole with high-strength retaining compound and allowed to cure in place. The inside of the threaded bushing is the thread that your pedal wants :)

Hope that's some help. Worst-case scenario, you might need to replace the cranks, bottom bracket, chain and cassette all at once. Been looking for an excuse to change your gearing...? Well there ya go :)
Ebbtide
06-09-03, 07:36 AM
I would guess most bike shops will steer you towards a new one, but any machine shop (or auto garage) will have the ability to re-tap it.

To go one further (how frugal are you?) you can have the shop (machine shop, friend with home welder, garage) weld the current ones in place on the back of the crank. (they might do it for free).

Hope this helps,

ehenz

Kev
06-09-03, 08:38 AM
One limitation in taking it to a machine shope would be the threading on the pedals. Since the one pedal is reverse threaded and this is not very common, they might not even have the part to do it.

I know I saw the other day a rethreading kit for the pedals threads on crankarms the other day.. it was either at loosescrews or biketoosetc but it was fairly expensive $60 or so..
mechBgon
06-09-03, 09:40 AM
You can re-tap threads that are a little gummed up. Almost all bicycle shops will have the taps for that. But if the threads have been pulled out, then you can't tap thin air :(

That's where the Eldi thread-replacement kit comes in... it replaces the missing metal. A Helicoil kit could do the same thing in a little different way.