cycleruk wrote: ↑23 Feb 2024, 11:36am
Not so modern but how about these :- Campag's version of external bearing chainset.
(Ultra Torque). These are at least 2010 and I only replaced them because I have now gone to 11 speed.
Not as easy to change the bearings as Shimano. You need pullers and the bearing is not a standard size. (
slightly narrower.)
Only on it's 2nd set of bearings in 20+ years and they are still fine. Admittingly was on my summer bike .
centaur crank 1.jpg
Centaur crank 2.jpg
Probably something similar in Shimano's older ranges as well.
One advantage with these older cranksets is they take standard easily replaceable rings.
FWIW I think it may be possible to convert campag ultra torque cranks to use shimano cups. Ultra torque has no layer of plastic betwixt the BB spindle and the bearing. Well hey,guess what you often end up with, using shimano stuff? Yeah, that's right, the plastic sleeve often wears before the bearing, making the cups ideal for use with campag cranks.The bearing ID in the shimano cup is the same as the campag bearings once the (worn) 'top hat' plastic sleeve is removed. I think it is best if a few microns is removed from the campag cranks so the push fit becomes a sliding fit and really needs a drop of adhesive. So, no puller will be required in future. The external parts of the 'top hat' bushes should be retained as they can still perform a valuable sealing function.
The final operation required is to make the widths/bearing preload correct..TBH I'm not exactly sure how this will work out but spacers can be added to the spindle or cup width, but if you want to make the cup width to be less the options are more limited. MTN cups will buy you another mm if you need it, and of course the BB shell can always be made a tad narrower if required. In any event, fine tuning of preload can be carried out using shims about 0.1mm thickness on the BB spindle. Such shims can easily be made using a coke/beer can. I suggest the spacer configuration required is finalised in a 'dry run' and then the whole shooting match is reassembled using an adhesive to mount the bearings properly.
One of the beauties of this conversion is that you lose almost nothing; the cranks can still be used with campag cups if necessary, although you will have to use an adhesive when mounting the bearings. If the bearings are first converted to DFC spec (and correctly adjusted/lubricated, including a perforated inner sleeve) then a very long life ought to be possible. IIRC the usual ball size in these bearings is 3.5 mm.
