When Shimano's 12-speed cassette hit trade show floors last year it made quite the noise. While the brand is famous for its pristine engineering and meticulous approach to components, we'd be lying if we said that its designers don't take their sweet time when new ideas hit the table. It may have taken a few years to see them jump into the twelve-speed game, but at the end of the day, we appreciate the time taken, as the end result offers precision that's been tested and well thought out -- and we're as pleased as ever to see the trickle-down technology seep through the lineup to the new SLX CS-M7100 12-Speed Cassette. The SLX 12-speed cassette sees all of the same smooth-shifting technology as its pricier brethren, but with more economical materials that allow Shimano to drop the price, making it all the more palatable when you're getting ready to upgrade your rig, or build up your dream bike. Shimano's 12-speed groupset pushes boundaries beyond its competition by offering multiple gearing options to better suit all kinds of riders. A close-step 10 - 45-tooth range cassette makes an ideal choice for intensely precise cross-country applications in which every small step between cogs makes a difference, while the beefier 10-51 cassette offers you the ultimate bail out cog for tedious climbs up steep fire roads when you're working your way to the second stage of an enduro race. And unlike other 12-speed groupsets, Shimano builds the CS-M9100 cassette to play well with both 1-by and 2-by applications, so you don't have to feel limited to a gear range that doesn't optimally suit you. Both cassettes are built to pair up with Shimano's Microspline freehub interface, allowing for room for that extra 10-tooth cog. When it comes to ramping, we have to say that Shimano's 12-speed cassette pushed well beyond our expectations, offering silky smooth shifting to its lofty cassettes. Hyperglide cogs utilize guide ramps on both sides of its surfaces, which pairs with its propr...