As per shop specs, this bicycle has Shimano XT M7100 chain (and this is printed on the chain so is true) and Shimano M6100 cassette. But there is M7100 cassette available on the market that even does not cost much more. M6100 is also available.

I was always thinking that M7100 is kind of series, so should match and it may be better as somewhat evolved model. Should I buy M7100 or M6100 when it will be due for replacement? Would M7100 perform better in any aspect?

Bonus question: M9100 is available, while that one costs twice as much. Would it also work?

2 Answers 2


It’s mostly about weight savings. The Deore (M6100) has all sprockets made out of steel. The SLX (M7100) has the biggest sprocket made out of aluminium. The XTR (M9100) has the three biggest made out of aluminium, the 4 smallest out of steel and the medium ones out of titanium (hence the high price).

Apart from the difference in material they should be very similar. All use the new Hyperglide+ tooth profile, all use the same tooth count (if we compare 10–51 cassettes) and are 12 speed for the new micro spline freehub body.

Aluminium and titanium are less hard and durable than steel but lighter. On bigger sprockets wear is spread over more teeth (and more teeth can engage at the same time) so they usually wear much slower which is why Shimano can get away with using those softer materials.

The weights are: 596g, 534g and 367g respectively.

If you were using the bigger/biggest sprocket excessively the M6100 (or M7100) could actually last you longer than the M9100.

As for what to pick: I kind of dislike the idea of spending a lot of money on wear parts (and cassettes are wear parts). But if you can afford it and think the weight savings are worth it: Go for it.

  • Worth really thinking if 229 g matters enough to justify the price of M9100. But the 51T sprocket sees no usage in my commuting where absolute majority of the distance is covered, so can probably be aluminium.
    – nightrider
    Aug 20, 2022 at 21:16
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    @nightrider The M9100 cassette also comes in a 10-45t narrow range variety. That may be worth looking into if you rarely use your existing 51t.
    – MaplePanda
    Aug 20, 2022 at 21:22
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    For completion, there's also a M8100 (that fills up the gap between the M7100 and M8100, obviously).
    – Rеnаud
    Aug 21, 2022 at 4:00
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    @Renaud Between the 7100 and _9_100 you mean :)
    – MaplePanda
    Aug 21, 2022 at 8:03
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    @MaplePanda You're right, sometimes I wish that there's no time limit to edit comments.
    – Rеnаud
    Aug 21, 2022 at 8:16

Besides weight saving, already mentioned, there can be another advantage: replacing small sprockets separately, which seems possible only for M7100 and up. I remember that you wrote that you were mostly using the small sprockets, so that can be another criterion to differentiate them.

Based on a quick search, it looks like you buy the 5 smaller sprockets separately for the M7100 and up (or to be more accurate, the 2 smallest together, then the 3 others separately). At current prices, the sprockets would cost 30€, while the RRP of the M7100 is 125€ (can be found at lower prices though).

EDIT: My conclusion was based on the availability of spare parts on online stores, that are not returning any references for the M6100 sprockets. But if I correctly understand the dealer's manual of this series of cassettes, the small sprockets of the M6100/M7100/M8100 are identical. Generally speaking, that is a criterion that differentiates upper ranges from the lower ones.

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