Rotor Chainset in a Giant TCR Advanced Pro frame

galatzo

Hi
Thinking of getting a Rotor chainset like the below and can't work out if it will fit my Giant TCR Advanced Pro 1 (2017)
On the one hand it looks like its a bb30 fit but the advert implies it fits almost all bbs.
Any advice appreciated.
Thanks

https://www.ebay.co.uk/itm/Rotor-3D30-C ... 1438.l2649

Changing it as I prefer Sram Force to Ultegra.

Beatmaker

It will fit with the correct Rotor bb.

964cup

Yes, it will fit with a conversion BB but not well. You'd be better off with a 3D24 for a TCR, as that's the native axle diameter.

galatzo

Thanks
I'll try to get to grips with the Rotor nomenclature a bit better.

pilot_pete

964Cup wrote:

Yes, it will fit with a conversion BB but not well. You'd be better off with a 3D24 for a TCR, as that's the native axle diameter.

In what way will it fit "but not well"?

I have no experience with the TCR, but a quick search reveals it is a 41mm x 86.5mm shell (if the TCR tech info I found is correct) which takes a press fit BB.

Rotor do press fit bearings (4130) to fit a 30mm crank spindle to this standard of BB shell. If installed correctly they will fit fine in my experience (admittedly not in a TCR frame, but in higher level press fit frames), with no creaking etc etc. It depends on the state of the shell you are pressing the bearings into (is it damaged, clean, etc?) and also using correct technique and the recommended Loctite bearing retaining compound after scrupulously cleaning all the surfaces. I have fitted and removed a number like this and they have been retained completely solidly with no creaks.

What I would say is that also in my experience the 4130 bearings simply sit in the frame and although sealed bearings, they are exposed to the elements, including water etc that gets into the frame. They have no internal shell/ cover between the bearings. I found that this caused premature (in my opinion) wear to the bearings and corrosion (only light and surface) to the crank spindle.

There is a solution to this, which is to fit a better quality (although sometimes significantly more expensive) bearing with an internal sleeve to protect the bearings from the inside and to enclose the crank spindle. I have fitted CBear ceramic bearings and they are superb.

All the above assumes a 30mm crank shaft, check the Rotor website for their BB compatibility chart which lists BB and crank options, so for example they will do a BB to fit a 24mm crank to your frame, but I would think that you could probably just fit a 24mm Rotor crank into your current setup (check if you need to fit any spacers).

Hope this helps

PP