Latest bike is perplexin me.

[JonnyButts]

I just got a Schwinn 210 fs from a friend for free. Its not a high end bike by any means but Its fun to ride and will good for the trails around home. I took it out for a spin and the crank arm came off. I removed the bolt holding the crank arm in and looked at the internal threading and the bolts threads as well, both were fine. Figured maybe it was loose already , so I tightened it back up , another 30 minute jaunt and the crank arm comes loose again :? Anyone have any suggestions on what I can do minus replacing the crank (I'll gladly do it but there must be some other fix) Thanks for helpin a noob out.

Jonny

 

[udallcustombikes]

Put a little thread locker (Loc-Tite) on the bolt and then torque it down.

 

[JonnyButts]

Thanks for the advice man, I have never seen a product like that before. Im going to try and find some locally and give it a whirl!

 

[udallcustombikes]

http://www.loctiteproducts.com/products ... 8&plid=695

 

[user 135]

If you are tighten the bolts down and the crank arms loosens, your crank arms are shot. The square alloy holes have been rounded out by the steel shafts on the BB.

 

[Walker]

The other way your crank arms can get worn out is that the arm will strech over the steel spindle. if the crank bolt is bottoming out on the spindle then this could cause the arm to come loose.

With the crank arm removed, inspect the tapered hole. can you see where the spindle has worn the inside, if it is worn all the way to the crank bolt seat then they are done.

If this is still inconclusive, install the crank arm. Then remove the bolt. Is the bottom bracket flush with the crank bolt seat?

good luck!

 

[JonnyButts]

Thanks for all the info Lads. I"ll take a look at the bike when I get back home after the easter weekend and let you guys know what I find. Again Much Thanks and Happy Easter.

 

[MadMick]

It's a common problem, the left crank bolt has a tendency to unscrew itself if not torqued enough during first assembly. Such a common problem in fact that every bike shop on the planet carries stock of left cranks. Home assembled bikes are the worst offenders.

If you can feel movement in a left crank when you're riding you are destroying it.

 

[JonnyButts]

Madmick: It is the left too lol, I'll inspect it but I have a sneaky feeling my LBS will be getting a few $$ from me when I replace the arm.

This place rocks, thanks for all the help lads, seriously appreciate it :!:

 

[JonnyButts]

Finally got a chance to look at this bike again (been working too much) The left crank was worn out and was easily replaced at my LBS. Now if I could just find the time to get out for a ride. Thanks for the help.