Crank arms
 

/i want to purchase new crank arms any suggestion i want decent ones but not a ridic price
How do i pick the size i need?

HEY-MR Marine-you just bought a new bike. Take it back to the shop you bought it from and get it fixed.

OR

Did you buy it used from someone?

I did I got the bike replaced I changed pedals already now I want to change crank arms just to elemanate the last problem I had

Quality costs, how much are you willing to spend?

Here are a couple of my favorite online sellers:

http://www.blueskycycling.com/cat-cr.../group-312/1/n Race face arms, usually $180 for $69. Might be overkill and might not fit your bike.

http://www.pricepoint.com

There are other places. Just a couple places to start. Get some riding in and see if the problem returns. I'm hoping it was a "UNIQUE" failure.

Get a allen key or a crank spanner and make sure that the bolts that attach your crank done up tight.
If the bolts are done up tight the cranks won't come off.

Cheap cranks installed properly will stay installed virtually forever. A $1000 crankset installed improperly will fall apart and make you unhappy. Bring the bike back to a reputable mechanic and ask him or her to check everything.

This. It wasn't the cheap crank, it was a poor installation job. Just have the shop fix the ones you have.

There is a well-documented correlation between improper riding apparel and crank arms falling off.

Sort out your incredibly dire clothing situation and your crank woes should go away within a few dirt rides.

If it takes more than a few rides for them to tighten up, starting more random threads in this forum can also help torque those pesky cranks down.