Campagnolo Record 11 Speed Cassette
Campagnolo gives us a perfect example of how to machine precision cogs and assemble a cassette. Record 11 cassettes feature Ultra-Shift profile synchronized cogs for improved shifting, and are mounted to a lightweight alloy carrier frame. The carrier shaves weight and the wider base provides better force distribution on the freehub body, especially important on today's lightweight aluminum bodies.
The smaller eight cog are a nickel-coated steel, which improves wear and reduces chance of oxidation. The upper 3 cogs are custom drilled and made of titanium. Titanium cogs are lighter than steel, and not as hard, so they tend to wear faster, though in larger cogs that process is slower. The smaller steel cogs wear better, and as they are used more and get more chain use per revolution. If you are comparing the Record and Super Record cassettes, this use of steel is the key to the longer wear of the Record version. And more titanium means higher pricing, meaning even deep-pocket Super Record riders use Record cassettes, at least on their training wheels. Campagnolo supplies an alloy lockring, the size of which is dictated by the choice of 11 or 12 tooth cassette versions.