What's really interesting is that Colnago have critically looked at the BB shell and come up with the following points.
1/ BSA threaded shells are good, brilliantly reliable and self aligning. The only negative being the limited available width for large tubes.
2/ Press fit B/B's have great width allowing the use of larger tubes but can be unreliable due to frame tolerances and frame deformation.
Colnago's solution for gaining frame width but keeping it reliable is actually quite simple...
1/ Colnago's Threadfit82.5 uses threaded press-fit adaptors that thread directly in to the frame, aligning the BB seats correctly and are easily removable and replaceable if damaged.
2/ The adaptors themselves take the (Shimano) standard BB86 bottom bracket enabling the installation of any crank set.
3/ Using an adaptor gives you a precision machined surface for the BB to fit to, opposed to carbon surface that can be irregular due to the manufacturing process.
4/ The increased diameter of the BB shell has allowed the Colnago engineers the freedom to increase the down tube size increasing stiffness and performance of the bike.
So in summery the C60 doesn't have yet another new B/B standard, it uses standard BB86 units with he addition of replaceable press-fit inserts meaning if you damage them you are not throwing a frame away...
My 'standards' alarm is well and truly silenced, clever stuff...
The C60 bottom bracket |
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