Bicycle Mechanics - replace b.b. or cranks?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : replace b.b. or cranks?


zoodude
02-02-10, 10:39 AM
Hey guys, I ordered the wrong atb square tapered cranks for my bike.:mad:

But hey it happens. So frame clearance and shifting into first gear are the current issues.

I was thinking if I just order up a b.b. with a longer spindle length that matches the cranks, problem solved. Am I in the right or should I bite the bullet and get another set of cranks and try selling these nice ones? Any tricks for this would be great!


DMF
02-02-10, 11:54 AM
Do you think you could possibly include any less information in your post?



New Posters - please READ THIS (http://www.bikeforums.net/showthread.php?t=338432)

rumrunn6
02-02-10, 11:57 AM
I vote eliminate the variables and get the correct part without replacing even more parts. no return policy?


DMF
02-02-10, 12:19 PM
Comparing the cost of the two options would seem to be determinate, too.

CACycling
02-02-10, 12:40 PM
BB will probably a lot cheaper than cranks. You need to find out what size BB is required by your new cranks first, however.

zoodude
02-02-10, 03:22 PM
"Do you think you could possibly include any less information in your post?"



Not sure what you mean. I am not asking about sizing numbers or specifics. Just if you can change out the b.b. for a different size on a bike and if it has any potential problems. If I had to guess it would be going from a 109 spindle to a 113. But I don't have a measuring device on hand.

davidad
02-02-10, 03:54 PM
What kind and brand of cranks and what type of bike they are going on. By the first gear do you mean the small chainring?

bikinfool
02-02-10, 04:39 PM
"Do you think you could possibly include any less information in your post?"



Not sure what you mean. I am not asking about sizing numbers or specifics. Just if you can change out the b.b. for a different size on a bike and if it has any potential problems. If I had to guess it would be going from a 109 spindle to a 113. But I don't have a measuring device on hand.

Well, in a way, you are asking about sizing numbers, but without the detail of what crank you're using....

The crank you're using determines the spindle length you need. You should be able to get the spindle length your cranks require. Good database here www.sheldonbrown.com/bbsize.html

CACycling
02-02-10, 04:44 PM
Well, in a way, you are asking about sizing numbers, but without the detail of what crank you're using....
Actually, he just asked if he should buy a BB to match his new crankset or another new crankset to match his existing BB and if there was a potential problem making one option preferable over the other. Never asked for assistance in sizing either item.

bikinfool
02-02-10, 05:03 PM
I was referring to the post I quoted in any case, where he is asking about specific spindle lengths...and doesn't seem to realize the relationship between crank and bb.

zoodude
02-03-10, 10:39 AM
It's cool guys, regardless of size it seems i can pull it off. So I am headed to the L.B.S. to get it measured and fitted. Fingers crossed. On the bright side I get both new cranks and b.b. :) Thanks for everyone's input and sorry if there was confusion.

Zoodude