Bicycle Mechanics - new BB/crankset worth it?

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cupcrazy4

05-29-08, 05:45 PM

I've got an old road bike (late 70s-ish) that I've stripped of everything except the BB and cranks. I want to convert this to a FG, but don't know if I should/need to invest in a new BB+cranks. Why do people get new BBs/cranks? My LBS says they can repack the BB for $20, and the cranks look ok to me (I can't really tell).
Also, is it still be possible to have a straight chainline with the old BB/cranks? (it was a double chainring before I took everything off)

powitte

05-29-08, 07:29 PM

The biggest reason for the new BB is chainline (http://www.sheldonbrown.com/chainline.html). If you can't achieve a proper chainline by moving your desired chainwheel to either side of the spider, a new BB is for you.

There's no mechanical reason (I can think of) your current crankset wouldn't be adequate for your purposes.