Bottom Bracket Dilemma



yNotTri

New Member
Jul 2, 2013
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Currently own a few bikes and trying to replace a crankset on a 2006 Cannondale R900. The bike came stock with the low end Campy group (Veloce) except for the bottom bracket and crankset. Cannondale opted for TruVativ GXP with the ISIS drive. What are the alternatives for replacing the crankset and if necessary the bottom bracket. Ultimately would like to replace with the Veloce crankset. I am by no means a bike mechanic and looking for some help to understand what the options are ?
Also have been searching for the specs on stock equipment and having trouble finding info.

Any advice would be appreciated. Before I go out and buy could use some understanding of what to consider !
 
The key thing is that your current Isis BB is threaded into an English BSA shell. IOW, you can use any English threaded bottom bracket on your bike. Purchase the crank you want and purchase the matching English bottom bracket and you're good to go. You'll need the appropriate tools to remove the current crank and bottom bracket and to install the new one or have a shop do it for you for a nominal charge but compatibility is not really an issue.

Alternatively you could keep your current Isis BB and find a compatible Isis crankset that you like but if you want a current generation Veloce crankset you'll want Campy's matching Power Torque BB cups but they'll thread into existing English BB shell.

-Dave
 
Originally Posted by yNotTri .

Currently own a few bikes and trying to replace a crankset on a 2006 Cannondale R900. The bike came stock with the low end Campy group (Veloce) except for the bottom bracket and crankset. Cannondale opted for TruVativ GXP with the ISIS drive. What are the alternatives for replacing the crankset and if necessary the bottom bracket. Ultimately would like to replace with the Veloce crankset. I am by no means a bike mechanic and looking for some help to understand what the options are ?
Also have been searching for the specs on stock equipment and having trouble finding info.

Any advice would be appreciated. Before I go out and buy could use some understanding of what to consider !
Although there may be exceptions, the GXP & ISIS designations typically refer to two different BB types, with the former having disparate external bearing specs & the latter being a splined spindle whose BB bearings are normally internal (there is ONE Bottom Bracket exception for ISIS splined cranksets which has external bearings).

FYI. Post-1998 Campagnolo Record/Chorus cranksets which use square taper BB spindles have symmetrical 102mm spindles ...

The OTHER square taper Campagnolo BBs are asymmetrical have 111mm for "double" cranksets ...

102mm Campagnolo BBs & TOKEN equivalents (some people say that the bearings on the Token BBs don't last ... I have one but I don't have enough miles on it to have caused it to fail, yet ... Token cartridge BBs use the ubiquitous "tool" which is used for Shimano cartridge BBs & THAT's a good thing) are probably more readily available, now, than the 111mm Veloce-or-equivalent BBs ...

  • IF NECESSARY, a non-Record/Chorus square taper, post-2000 Campagnolo crank can be mounted on a 102mm Campagnolo/-compatible BB if you shim the non-driveside (Centaur/Veloce/Mirage/Xenon) crank arm if the non-driveside is properly shimmed, then you will then end up with the same 145mm Q-Factor which the Record/Chorus square taper cranksets have
[*] there ARE some advantages to the newer UT & PT Campagnolo cranksets which have external BB bearings ...
  • but, IMO, the advantage may be mostly cosmetic (THAT's a good enough reason)
  • and/or, availability (that's also a good reason)

The DOWNSIDE of Campagnolo cranks is that they use proprietary chainrings ...

  • even the "compact" crank has a semi-proprietary 110BCD spider (you can elongate the 5th hole of a standard 110BCD chainring so that it can be used on a "compact" Campagnolo crankset)

The bottom line is that you should choose the Campagnolo crankset & BB which fit your budget & suit your aesthetic sensibilities.