Which Truvativ cranks are you talking about? That'll help.
Generally speaking, a 68mm BB does not work in a 73mm shell. If Pricepoint dosn't list a 73mm shell, they're probably out of stock.
Truvativ cranksets with external BB's are compatible with both 68 and 73 mm shells. Since the crank spindle is a fixed length, the crankset is designed around a 73mm shell, then spacers are used for 68mm shells.
If your looking at Truvativ ISIS or Howitzer setups...those are also compatible with 68 and 73 mm shells...again, using spacers for the 68mm shell.
I was just on the Pricepoint page and I don't see any Truvative BB's listed as 68mm only
Torque me. Make me spin!
mtnbiker is right. Any 73 mm BB should work on a 68 mm BB shell as long as the spindle is long enough to provide the desired front chain line. But some 73 mm BBs do not come with the 2.5 mm spacers needed to allow them to fit on a 68 mm BB shell. Make sure your BB comes with these spacers or that you can get them somewhere.
As I recall, XTR BBs (old school <~2003) come in only one shell width. The XTR BB includes multiple spacers to allow it to work on 68 mm shells, 73 mm shells, and with or without E-Type derailleurs.
BottomBraket line: If you’re stocking up on bottom brackets, get the 73 mm width because you can get spacers to make them fit on 68 mm shells.
Alright thanks guys. So if he orders a 68 with the right spacers it will work with his 73 as-x frame?
Torque me. Make me spin!
A 73 mm bottom bracket (the housing, bearings, and crank spindle) with spacers will work in a bike frame with a 68 mm bottom bracket shell.
But a 68 mm bottom bracket (the housing, bearings, and crank spindle) made specifically for a 68 mm bottom bracket shell probably won't work in a bike frame with a 73 mm shell. The drive side (right side) crank arm will be 2.5 mm further from the bike frame, increasing the front chain line. Also, the non-drive side (left side) crank arm may rub against the frame before the crank arm is fully tightened. Eg., the crank spindle will be 2.5 mm further to the right.
Ask the vendor if the part you want will work with either a 68 mm or a 73 mm bottom bracket shell. Or check with the manufacturer about the compatibility of the specific crank and bottom bracket part number.
This can be confusing because "bottom bracket" can mean two different things.
1) bottom bracket- such as Shimano part number BB-M952 (the housing, bearings, and crank spindle that screws into the bike frame
2) bottom bracket shell - the part of the bicycle frame at the bottom of the down tube and the seat tube that is a cylinder about 1.37 inches in diameter (most modern bikes) cylinder and either is typically 68 or 73 mm wide.
Last edited by BottomBraket; 10-28-2007 at 07:31 PM.