I have a Quarq Elsa GXP on a 2008 Cervelo P2C and would like to transfer it over to a newer Cervelo with a BBright bottom bracket. What does this involve? Is it simply a matter of getting the correct adaptor?
I’m in a v similar position: GXP Elsa plus a new BBright bottom bracketed P3.
I asked Damon Rinard at Cervelo about this, and specifically using and installing the Enduro GXP to BBright adaptor. He replied:
"for constant switching I’d suggest the Rotor BBright to 24 bottom bracket. Go to Rotor’s USA web site
http://www.cart32hostingred.com/...&Theme=Basic%202
and GXP is an option in the pull down menu. Really simple: they added a bushing to the left bearing of their Shimano compatible bottom bracket to match GXP’s 22mm side.
Be sure to install it in your frame following the BBright Pressfit Instructions linked at the bottom of the BBright home page: http://bbright.net/ "
The Rotor BB is on its way to me now, as is the P3, so I can’t give a view yet on how easy the installation is.
That doesn’t seem too bad. Let me know how it goes. Hopefully the whole setup is solid and quiet.
Actually I just noticed that that adaptor does not work on the P5. The bike I was planning on switching it to is the new P3. Presumably the adaptor will not work with that bike either.
I hope it will, because the P3 I have on the way is the New P3!
I’ll let you know.
If you mentioned to Damon that the bike in question is the New P3 then I am sure it will be fine. I have no idea why the Rotor site indicates that the adaptor will not work with the P5, and I also am not sure that the New P3 and P5 are identical through the bottom bracket.
I did mention it, so it should be OK.
It is curious that there seems to be BBright, and P5-BBright though…
Hi Scott,
Great points, thanks for helping clarify.
Just to be clear, the Rotor bottom bracket fits in the new P3 no problem. It also fits later model P5s, and later model Rotor bottom brackets even fit early model P5s. The issue was a vestigial ridge of unneeded carbon (a byproduct of how the shell is molded) that interfered with early Rotor bottom brackets. Fixed on two fronts: We eliminated interference in later P5 frames, and Rotor eliminated interference in later bottom brackets, so only early frames and early BBs might interfere. In that case, the fix is simple: dremel down the ridge in the frame by about 1 millimeter. Done in 20 seconds.
To answer your other question, the new P3 is different in the bottom bracket than the P5; for one, there’s no brake in that area on the P3, which eliminated the molding process that lead to the ridge in the early P5; and second, having learned from the P5, we designed the P3 from the start to be compatible with even the early Rotor bottom brackets.
Hope this helps,
Cheers,
I’ll be swapping the same crank between a P2 and S5 (if it ever shows up). This is another option http://www.c-bear.com/en/bbr-en/sram-gxp-bb-right-bottom-bracket.php
Brilliant - thanks Damon for that. V helpful.
Damon, thanks for the clarification. Good to know that a switch to the New P3 would not also require a change in power meter.
Hi Greg,
Just to put you at ease, there is no “new” BBright standard, and no changes since it was introduced.
Let me explain: there’s a minimum frame ID defined in the BBright technical drawings, and all Cervelos respect that dimension, even early P5s. Rotor used an OD on their cups that was larger than the minimum frame ID, against the standard. At first it was no problem, because at the time most BBright frames (S5, R-series) were already compatible; they didn’t use the full dimensional envelope allowed in the standard: they didn’t have that small of an ID. With the P5, only the BB-mounted rear brake made it different: the brake recess on the frame’s outside invited us to allow a smaller ID, down to the limit defined in the BBright standard, for the first time “evar!” I discovered this together with Team Garmin-Sharp mechanics when we were assembling Rotor bottom brackets in the first P5s (one of which was used by Ryder Hesjedal to win the 2012 Giro d’Italia a month later). Then as now, the fix was to dremel down the ridge in the frame by a millimeter or so to let the cup fit inside.
We (Cervelo and Rotor) implemented the changes described in my previous post, and now all’s well.
Reference the BBright.net home page http://bbright.net/ and the technical drawings linked there: http://bbright.net/bbrightdrawings.pdf. The dimension we’re talking about is the “44.5 MIN” inside diameter on page two; I think Rotor used to have something like a 45mm OD on their cup where it assembled into that space.
Cheers,
How’d that Rotor bbright - gxp bb work out?
This is the install write up that I posted on the Cervelo forum. I’ve used it a fair bit since then, and it’s running perfectly.
"So, how did it go? Well, not too bad. But whoever choose the word “press” for “press fit” had a good sense of humour.
The Rotor BB has a nice solid feel to it. Just to check it was in fact the right thing, I tried the DS and NDS cups on the crankset without the frame. All good.
Being fundamentally a bit lazy and a bit “make do” I didn’t bother with an installation tool (I ordered the removal tool though as I could see things going *** up from a long way off, and wanted some cover). Instead I cut two squares of plywood (4mm thick, sufficient to cover the faces of the cups) and bought a 150mm G clamp.
As per the BBright.net instructions I greased the NDS cup and shell, and applied Loctite 680 to the DS cup and shell. I was able to insert the cups a little way into the frame, but pressing made no difference. So the ply and G clamp came out. It’s quite tricky with only one pair of hands to get everything lined up and tightened lightly without stuff dropping to the floor, but eventually I had it all lined up ready to apply proper pressure.
First thing was that it requires a lot more force than I expected to get the cups in. Second was that the greased cup slid in fairly easily. Third was that the DS cup tended to go in in jumps. It would sit still with pressure building, then “pop” and move in a couple of mm. Then soak up more pressure without moving, then"pop" again. And when I say pressure, I mean it - the ply was cracking quite badly. At one point I thought I was going to have to cut some fresh bits.
Once it was in I put some grease on the bearing covers to provide some tackiness to hold them in place. Then ran the Quarq through the BB - I was strangely relieved when I saw it pop out the NDS. Torqued it to 54Nm, half expecting the whole thing then not to turn, but it turned smooth as silk.
All in all, pretty straighforward."
I haven’t transferred the Quarq over to the new bike since it is not scheduled for delivery until February.