Noisy gears, a possible fix

ugo.santalucia

I've been marred by noisy chain on some sprockets, typically the smaller ones. Shifting is fine, the B screw optimised, all good, but the chain is noisy on some sprockets. Looking at the bike from the rear, the derailleur cage doesn't appear to be very vertical, so it was tempting to blame the usual mech hanger. However, on closer inspection, one notices that releasing the QR realigns the derailleur cage to vertical, so it appears the problem is a mismatch between the frame dropout distance (130.5 as measured) and the hub (have not measured, as it requires removing the cassette). I've botched a solution by adapting a 1 mm thick, 10mm ID washer I found in the nut box to fit on the left side hub cap, so that it widens the hub a bit to fit more snug. It does the job well, gear noise much reduced and there is no appreciable difference in the wheel centering. Very minor adjustment required to the rear derailleur, really just a quarter of a turn of the adjusting barrel.
For a more refined fix, I have ordered some 0.25mm washers from Ebay, some 10mm ID to fit to the hub cap and some more ambitious 15 mm ID to fit directly to the axle inside the hub caps, just resting on the bearings. The latter would do a more elegant job, if it doesn't jam the bearing, although they might compromise the hub water tightness to some extent.

Anyway, long story short, this might be the problem you are actually experiencing and wrongly blaming the mech hanger. So, check the fit of your rear hub in the dropouts... if it is too loose, try my fix before ordering a new mech hanger

ugo.santalucia

I have now fitted 15mm ID 22 OD washers on the NDS, I tried to match them on the DS, but they had no effect, probably the cap does not rest onto the bearing on that side. It is a more practical way to arrange them than outside directly aginst the dropout. They might compromise the water tightness, or they might actually protect the bearing further from the elements, time will tell. These are race only wheels anyway, so they won’t see a lot of water