Originally Posted by
FBinNY
The most important difference is that Miche cassettes are all loose sprockets going directly to the hub with spacers in between. Better Campy cassettes have the larger sprockets on carriers (spiders or what have you) with only the smaller sprockets sliding on the hub.
This can be important because Campy hums have aluminum freehub bodies, and at high torque sprockets can cut into the body a bit. Sometimes it's only minor, but I've seen many hubs where the raised metal this causes makes it near impossible to remove sprockets.
Have you seen that with Campagnolo splined freehubs, especially of Campagnolo construction and not just other manufacturers Shimano/SRAM splined parts?
Campagnolo 9/10/11 cog splines are _much_ more substantial than Shimano.
Out of curiosity I used my dial caliper on both flavored Powertap freehubs and got .120" deep on the Campagnolo splined example which is over twice the .050" height of the Shimano/SRAM splined part.
Aluminum hardness also varies with the alloy; Campagnolo brand Campy splines could be tougher than aftermarket Campy splines.
So if you're not in a hilly, use 23t cassettes, and don't pound biggish gears up short steep hills, you needn't worry. But if you want a 28t and climb steep hills in your 39/28 combination you really want to use the Campy cassettes so you don't beat up the freehub as much.
My 97-98 Record freehubs remain unscathed in spite of a steady loose cog diet. While I run 23 big cogs I've done so with 34 and 30 small rings which result in the same torque as a 39x26 and 39x30 respectively including rides in the Colorado Rockies.