cassette gearing Jim 7 speed cassettes

cassette gearing Jim 7 speed cassettesSEVEN 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

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 9/10 speed T610 cassette hub, you just slide on the 4mm spacer The cassettes come with this spacer.

2. On a SILVER brand or Shimano 11s rear hub, you use a 4 and 1mm spacer.  Note: You don't need spacers on a 7/8 speed cassette body.

A 4mm and 1mm spacer for 9/10 speed hubs are included, as already stated.  If your hub is 11+ speeds then you may need another 1mm spacer.  You can also use an old 12t/13t cog as a spacer. 

Our 7s cassettes are made in China by S-Ride (former maker of SRAM cassettes). They are lightweight, all-steel, and shift great. Ratios and weights: 

11, 13, 16, 20, 24, 28, 32----284 grams / 10.01 oz

11, 13, 16, 20, 24, 30, 36----317 grams / 11.2 oz (convert to grams, multiply x 28.35)

13, 15, 18, 21, 24, 28, 34----309 grams / 10.9 oz

13, 15, 19, 23, 28, 34, 40---390 grams / 13.76 oz

13, 16, 20, 24, 30, 36, 42t---400 grams / 13.9 oz

(lighter than a basic Shimano 9s cassette)

Check out our gear inch calculator if you really want to fine tune your gearing.

• Shimano HG compatible cassette

• Nickel-plated steel cogs

 You need this tool to remove and install a cassette.

 "Jim" in any of our product descriptions indicates a close collaboration with Jim Porter from SomaFab/Merry Sales. He is a third-generation owner of a bike importer and distributorship that goes back to the 1906, and is really smart, well-connected, similar-in-thinking and values to us, and Gets Things Done. 

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Backstory Stuff: On getting these from China; and indexing with these

When SRAM took its manufacturing from China to Taiwan, probably but who are we to say, to avoid the raised tariffs, it left a colony of Chinese designers, engineers, marketers, and assembly people out of work but still chock full of skills and rarin' to go again. Out of the original batch came at least three new brands: MicroNew, S-Ride, and Sensah, each with its own areas of specialization. For 27 years we sold nothing made in China. COVID has made it impossible to source only from Japan or Taiwan while continue equipping bicycles on time and with the kind of stuff we like. We have nurtured what seems to be a good relationship with some Chinese vendors, and guess what--if they can make Apple products, they can make bike parts. Equally, they're eager to do so, at a time when most Taiwan vendor will laugh your pants off and tell you to leave the room if you want something new, even if it's right up their alley, and furthermore, if you want it within three years. These 7-speed cassettes are made by S-Ride.

INDEXING

We're not an R&D lab, but we dissect things and learn about them deeply, from a bike rider's and bike mechanic's perspective, and purely as a matter of curiosity, Vince and Rich here combines brains and discovered how to make 9-speed indexed shifters work seemingly perfectly with these 7s cassettes. The following instructions are intended for those with mechanical skills and sufficient experience with fussy indexed drivetrains.

Here's all you do, baby: Put the chain in top gear (big front, small rear), with the big paddle fresh and the cable loose. Click twice, essentially wasting the first two clicks. THEN tighten and snug the cable,  The next seven clicks seem to shift perfectly. Your results may vary, but it worked great here. We still recommend these for friction shifting...or if you happen to have some dusty, cruddy, eBay'd 7s indexed shifters, try them.