Loose Crankwheel.

I have a cheap, chain store mountain bike. The crankwheel became wobbly on pedaling just 130 kms and it was repaired by the store after some big efforts on my part. Now, upon cycling just 40 kms, again it is becomming wobbly.

Is this easy to repair ? If yes, how ? Any other related suggestions/advice, appreciated.

Thanks in advance.

Vijay

 

Okay, by crankwheel I assume you mean the drive side crank arm (this is the arm that attaches to your pedal) I am not sure if this is what you are referring to but if it is an Allen wrench should tighten up the bolt that secures the arm to the bottom bracket (the mechanism that allows you to pedal). If the bolt continues to loosen up throw some loctite on the threads of the bolt. Of course this may not even be the problem, try getting more specific in your description. God speed.

 

Not sure what type of Bottom bracket you have, but the Bottom brackets cups could be loose as well as, or the bofore mentioned crank arm bolts. Maybe the BB is worn out?

 

This bike is almost brand new, got it only todards April end, so far has just 175 kms or so on it. So don't think the bb can be worn out so fast.

Vijay

 

Actually, the entire axle that the pedal is attached to seems a bit wobbly. This in turn makes everything including the crankwheel wobbly. Wonder why the axle is getting so wobbly, so fast ?

 

I would gather the crank arm bolts are loose and or the BB cups are loose. Like mentioned you could try a little bit of blue locktite on the crank bolts to keep it all together. When I put my bike together last year I had a heck of a time getting rid of creaks and squeeks and my BB kept getting loose. I used plumbers tape on the BB threads to quiet the noises and locktime on the crank arms. Worked well. If you don't have the tools and such just run it over the bike shop and tell them it keeps getting loose on you. Since it's so new they should fix it for free!

 

you need to be careful, however, if you rode the bike with the crank arms loose you may have worn them out. If they are worn out they will never again tighten up the way they once did. If that is the case and the shop is at fault it should be replaced under warranty, of course you will have to again plead your case to them. Good luck.

 

I went to a local bike club and learned that it was just the circular ring that holds the bearings that is damaged/bent. They didn't have a new one.

So went to another local store that charges just for parts and installs for free. They have ordered that part and will install it soon as it arrives.

This is more efficient than using the warranty, specially as these smaller bike parts are quite inexpensive, was told this will cost around 3 to 4 bucks.

Vijay