SEVEN is plenty for any riding we do, probably any riding you do. Mountain bike downhillers ride 7s cassettes, but in close ratios. We're now having them made in normal and wide ratios good for hills, too.
It seems like a unabomber strategy, but it's a mild, sane, ultra-reasonable, fantastic — as becomes apparent once you know the details. In fact, once you know the details, it's the other cassettes that have some explaining to do.
WHY "ONLY" SEVEN? Why not 9-10-11-12-13?
• Better chainlines. It makes the big chainring x big cog combo usable. Since the big cog is now more right-board, the chain's path to it is less angled. It's where the next-to-biggest cog is on a 9-10-11-12-13s cassette.
• Longer lasting chains and big cog teeth. This is slight, and nearly immeasurable, but the straighter the chain runs, the longer the drivetrain lasts. We find it super-useful to be able to use the big x big combination--it essentially gives you an extra (and really desirable) gear combo. On my trail Clem, the 34 (big front) x 42 (big rear) is my most-used gear.
• Fewer cogs to shift thru. MORE cogs is useful ONLY if you pedal at a fast and narrow range of cadences. Like, if you lock in at 90-98 rpms. That's peloton and racing pedaling. On solo rides, trails, and regular recreational rides with people you know, I bet your cadence is "whatever feels natural," like mine is, and I'll also bet that's something between 54rpms for hill grunts, and 75rpms for fast riding on flat roads. The 7s cassette is ideal for that. They come in a 34t and a 42t low, good for a lot of roads and trails.
• Works with 7-8-9-10-11 speed chains. Currently the 7s sets ups we're riding have 10s chains. Perfect.
Recommended for any friction shifters, but see the note at the bottom of all this.
1. On a Shimano Deore 9s T610 cassette hub, you just slide on a first. The cassettes come with this spacer.
2. On a SILVER brand or Shimano 10s rear hub, you use the . Note: You don't need spacers on a 7/8 speed cassette body.
Spacers are included, as already stated.