Page 1 of 1
Rotor conversion BB with C'Dale crank?
Posted: Tue Feb 18, 2014 3:47 pm
by FastforaSlowGuy
I'm sure this has been asked before, but I can't find it. Has anyone tried to use a Cannondale hollowgram with the Rotor BB (the one that allows use of their BB30 crank on a BSA bike)? I thought I read somewhere the axel length is off, or something.
Sent from my iPhone using
Tapatalk
Re: Rotor conversion BB with C'Dale crank?
Posted: Tue Feb 18, 2014 5:27 pm
by bikerjulio
You will have to do some research on spindle lengths available with the Cannondale, but I strongly suspect the answer is "no".
Currently there is what is effectively a "long BB30" standard evolving, otherwise known as BB386EVO. It uses a 30mm spindle but with the bearing spacing of a 386BB. (Which is derived from a regular old fashioned BSA BB with outboard cups). Right now FSA, Rotor and Campagnolo make these cranksets, possibly others too. It's a flexible solution for a wide variety of BB shell types, including BSA.
A "regular" or standard BB30 system puts the bearings closer together and uses a shorter spindle, which is probably what you have, although you need to be more specific about what crankset you have.
Re: Rotor conversion BB with C'Dale crank?
Posted: Tue Feb 18, 2014 5:27 pm
by Weenie
Visit
starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com
Re: Rotor conversion BB with C'Dale crank?
Posted: Tue Feb 18, 2014 5:41 pm
by TimmS
Yes it can be done. You need a longer spindle and modify it a little bit.
If I remember correctly you need a 122 mm spindle.
As a result your chainrings will be 9mm more outward and the q-factor will be 18mm wider.
If you don't care about this it will be perfectly fine.
Re: Rotor conversion BB with C'Dale crank?
Posted: Tue Feb 18, 2014 6:45 pm
by bikerjulio
TimmS wrote:Yes it can be done. You need a longer spindle and modify it a little bit.
If I remember correctly you need a 122 mm spindle.
As a result your chainrings will be 9mm more outward and the q-factor will be 18mm wider.
If you don't care about this it will be perfectly fine.
This illustrates another problem - primarily chainline and to a lesser extent the Q factor.
These problems would not be there in a "BB386EVO" type crank which would provide the correct chainline. I'm not sure you could get a FD that would work with a crank 9mm further away, plus the undesirable chain angles that would occur.
Re: Rotor conversion BB with C'Dale crank?
Posted: Tue Feb 18, 2014 7:56 pm
by eric
The bad chain line and Q factor make the Cannondale conversion a non starter.
Sram Quark BB30 cranks are "long BB30". So are Lightning.