BBright, Rotor Cranks and Cervelo frame

frankieridesbikes
frankieridesbikes Posts: 2
edited May 2014 in Workshop
Hello,

need some urgent help.

Just bought a Cervelo R3 famrse - it came with a SRAM press fit BB. I'm using rotor cranks with this.

However, turns out the the BB is too small for the Cranks.

I thought that the pressfitBB was compatible with these cranks? Cervelo use the BBright and here was me thinking that Rotor cranks would fit nicely?

Do i need another press fit BB or an adaptor?

Help would be appreciated.

Thanks

Comments

  • sungod
    sungod Posts: 17,352
    you can get pfbb for different diameter crank spindles

    so if you've got one for 24mm spindle, but your rotor is, say, 30mm, you'd need to replace the pfbb with the correct one
    my bike - faster than god's and twice as shiny
  • napoleond
    napoleond Posts: 5,992
    My Rotor cranks fit in my SRAM pfbb fine :?
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • Monty Dog
    Monty Dog Posts: 20,614
    Depends on model year of frame - latest is BB Bright which is a proprietary 30mm spindle job
    Make mine an Italian, with Campagnolo on the side..
  • napoleond
    napoleond Posts: 5,992
    Mine's a 2011 with BBRight BB. The spindle is mahoosive!
    Not sure what BB for 2010...
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • EDWheel
    EDWheel Posts: 1
    Hello,

    This answer is a bit late, but might help others...especially with the tricky detail I had to learn the hard way :-)

    As Rotor state their general/normal* cranksets fit with all bottom bracket (BB) standards, and there are really only two exceptions for UBB30 and for UBB24 not yet exist a BB386Evo solution. Simply have a look on the different charts Rotor provide on their Webpage with their (1) cranksets bottom brackets compatibility chart, (2) the chart comparing Rotor's Universal Bottom Bracket (UBB) concept with competitors crank types, and (3) the table with more details like Q-Factor measures, available crank dimensions, several compatibility information, etc...
    1. http://rotorbike.com/media/files/2012/1 ... 662450.pdf (very helpful)
    2. http://rotorbike.com/media/files/2012/1 ... 662396.pdf (shows with which BB standard Rotor cranks fit)
    3. http://rotorbike.com/media/files/2012/1 ... 747508.pdf (provide some more details)

    So Rotor has cranksets with 24mm and 30mm spindles, and different Bottom Brackets that combined the right way fit with nearly every standard (see 1st and 2nd URL).

    Now to the Cérvelo Rotor cranksets. Rotor models are changing, e.g. the older basic model isn't sold anymore, and the new basic models 3D24 and 3D30 show now the same, or nearly the same construction as the 3D+. The older basic model bearer clearance were adjusted with the cap piece screw that is attaching the left crank at the spindle, and all was fixed then with the left crank spindle clamping. In contrary the nicer 3D+ design use the cap piece screw, now on the right side, to attach the right crank to the spindle and fix it. For the bearer clearance adjustment the left crank has a screw that is situated between left crank and bottom bracket after the installation. This way the overall crankset bottom bracket installation can be tightened to adjust the bearer clearance. This screw can be locked by itself with a small clamping screw after adjustment is done.
    So the Cérvelo Rotor cranksets are basically Rotor 3D+ models, at least I never saw the older model installed on a Cérvelo. Another detail is that the cap piece screw in contrary to general/normal* Rotor 3D+ cranksets is mostly black and not red.

    *What does now general/normal mean? The point is, as I had to find out, the 3D+ Cérvelo Rotor cranksets are produced as specified by Cérvelo for their BBRight bottom brackets. Though the 'general' Rotor 3D+ crankset really fit with nearly all BB standards, whereas the 3D+ Cérverlo Rotor crankset does not. They have shorter spindles and this way fit very tight and nice with Cérvelo frames, i.e. no big washers. That is actually not a problem until you would see a nice offer of a Cérvelo Rotor 3D+ crankset with a good price and want to install it on a frame with for instance a Pressfit 86 bottom bracket. It doesn't work, the Cérvelo Rotor 3D+ crankset with both cranks attached on the spindle and the screw tightend only show a distance of 82mm between the cranks (Pressfit 86 with bearings installed show >= 90,5mm). It also means that the installation instruction you can download from the Rotor Webpage that describe the use of the different washers for different BB standards will appear to be strange when things do not fit as described.
    So the Rotor cranksets you can buy fit nearly for every standard, also will fit with a Cérvelo frame; will look different due to the necessary washer. In contrary the Cérvelo Rotor 3D+ cranksets use is limited due to the shorter spindle (available 82mm between cranks).

    Hope this information help to avoid surprises when looking for Rotor crankset offers.

    Kind Regards,

    P.S.: I've clarified it with Rotor support :wink:

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