This is my first installment on the Tech Talk.

To limit the scope of the talk I am going to talk about Dura-Ace, Ultegra, and 105 compared to Record, Chorus and Athena in 8 speeds. I will cover 9 speeds in a special talk.

What is the big deal about cassettes? Shimano offers a range of cassettes 12-21, 12-23, 13-23, 12-25, and 13-26 across the line for each of its three gruppos. Campy offers 11-21, 12-19, 12-21, 12-23, 12-25, 13-21, 13-23, 13-26 and 14-26 in steel and 12-21, 13-21, 13-23 and 13-26 in titanium. Ok, so Campy has more of a choice do I really need it. For the vast majority of riders Shimano offers a good choice of gears. Campy offers a better choice for specific conditions. Here in Florida it is flat and we use a straight block (12-19 or 11-18). There are no hills and the lack of gaps in gearing lets you always ride in the exact gear you would like. The 14-26 (14,15,16,17,19,21, 23,26) is a cool choice for the guys that ride in the hills. You still have a 16 tooth cog which combined with the 53 up front allows for cruising in the 21 to 23 mph range in comfort. Shimano drops the all important 16 from all the big back cog cassettes. The other thing to note is the lack of 11 tooth rings in Shimano. The 11 tooth cog can make a 3 mph jump in the top end of bike. Most riders can't use the 11/53 gear, but there are riders that can and they look to Campy. You could find yourself wishing for a gear that Shimano does not offer.

Is there a difference in the quality of the cog sets? Yes, quite a bit.
Campy makes a thicker cog than Shimano. More steel means longer life. If you ride once a week you will probably never notice. The guys that ride 200 or more miles a week will tell you the Campy cassettes run longer. With the exception of Dura-Ace the Shimano cassettes come joined together so that it is not easy to make cog substitutions. The 105 and Ultegra need to be joined into a bundle (minus the smallest 2 cogs), because the rough stamping of the steel is not precise enough to keep them from cutting into the spline of the cassette body. If all the big cogs are joined into a bundle it has enough surface area to prevent this. Campy makes each cog in a precise stamping that allows each cog to be self supporting. This means it is possible to buy a single new cog and replace it in the cassette, because it it not joined to its 6 nearest cogs. It is also possible to take two cassettes and make a new cassette with different gear ratios.

What about the titanium cog sets? If I have Shimano I can choose a number of aftermarket suppliers to get my Ti cogs. Talk to the people that use the aftermarket cogs and see if it shifts like the steel. You will find the answer is no. In most cases people go back to steel. Campy Ti cogs work as well as the steel version (for fewer miles). The only problem with the Campy Ti cassettes are they require a different hub (deeper spline pattern).
The Shimano aftermarket cogs go on the same cassette body which saves the need for a second rear wheel and cassette. If you go aftermarket with Shimano you may need to change out the pulleys on the derailleur so they do not have any play to accommodate the wider Ti cogs. Campy offers a factory direct full Ti rear end if you feel you need it, that Shimano has ignored up to this point.

So, is Hyperglide better than Exa-Drive? Not really. They are both designed to do the same thing. At this time I would call it a moot point to argue the benefits of one over the other. They both shift well and offer better performance than their previous cassettes.

Tim Laflin