yet, another bottom bracket question

[bmorekirby]

ok, what determines the axle size on the bottom bracket? the crank arm?

[dookie]

I believe that the axle size is dictated more by several characteristics of the frame. One of these characteristics is the chainstays. (horizontal bar running from bottom bracket to rear axle) Some chainstays are square, oval or round, large, notched, straight, S-shaped, etc. Bigger, non S-shaped chainstays will require wider BB axles. Also, look at the clearance between the front chainring and the frame. Sometimes running a front freewheel may require a wider BB axle because the freewheel is much thicker than a chainring. You can use longer or shorter BB axles to adjust the chainline, trying to keep the chain as straight as possible in the gears that you use alot. And, yes, the cranks as well. You want to make sure your crank is clearing the chainstay.

[bmorekirby]

well, its going one a bt raven 5.0, if that helps

[Matt]

If you're wondering what specific bottom bracket size you need for the BT Raven 5.0 I recommend dropping a Private Message to "RomanC" as he is the distributor for BT Bikes here in the U.S.

As for your question about bottom brackets, I think dookie pretty much said all that could be said.