Originally Posted by
PVFD304
I have a Campy 9 speed 11-25 rear cassette. Does anyone sell a 28 sprocket to replace the existing 25 without buying a whole cassette?
Miche.
I tried Harris, they had one to fit a 10 speed but no 9 speed 28 tooth cog. Seems the 9 speed and ten speed freehubs are different.
It'll fit and you shouldn't notice the .002" difference in cog thickness (1.7 vs 1.75mm).
9 and 10 speed freehubs have the same spline pattern so cassettes interchange.
Steel 8 speed freehubs have a larger inside diameter on the splines and won't take 9/10 speed cassettes. They're 1mm narrower too.
"Record Titanium" 8 speed alloy freehubs are their own thing with the 9/10 speed diameters but missing the step on one of the wide splines and take a little grinding on 9/10 speed cogs to make them fit.
Record/Chorus from 1999 on and everything else 2000 and newer take a 27x1mm lock ring.
9 speed hubs from before then take a 26x1mm lock ring.
8 speed hubs take a 29x1mm lock ring.
Also note that you'll be exceeding the wrap (27T) specification on a Campagnolo short cage derailleur (55mm between pulley bolts vs 72.5 for a medium and 89mm for a long) and may end up with a slack chain on the inner ring and smallest cog(s).