Not sure if I'm using the right terminology here. Last night I changed the chain on my cheap road bike (2008 Specialized Allez Triple), and then took it for a quick test drive but the chain was skipping under any load at all. Figured the cassette is well done as well.

The problem is it's very hard to find a 12-26T where I am for some reason, but there are stores with 11-26T in stock. Would this cause big issues? Anything I should check for before I buy and install?

Also, I am sure I've seen people do this, but right now everything is Shimano, but the only cassette's I can get are SRAM, shouldn't be an issue correct?

1 Answer 1


This would be completely fine. You only really have to worry when going to a much wider range. Smaller road derailleurs cannot deal well with big differences between the largest and smallest gear, but they can all handle a 15 tooth difference. Things only start to get compatible once you move beyond 11-28. Shimano/SRAM are compatible for 8-9-10 speed cassettes. Things aren't compatible at the 11 speed level. According to this chart, Shimano and SRAM mountain Cassettes are compatible at 11 speed, but for the road there is a small difference in sprocket pitch.

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    OK so that definitely helps with my last question. Are you also saying going from 12-26T to 11-26T should be acceptable as well? Edit: Or wait, maybe thats what you meant by the 15T difference between biggest and smallest. My bad
    – Danny
    May 4, 2016 at 14:49
  • Yeah. The part about the 15 tooth difference addresses this. You only have to be careful if you're fitting "mountain" cassettes on road bikes. Even though they are technically compatible in terms of spacing between the sprockets, road derrailleurs cannot handle the amount of chain slack that would result when using something like a 12-42 wide range mountain cassette. If you wanted to use a mountain cassette on a road bike, you'd have to switch the rear derrailleur out for a mountain derailleur which for Shimano are actually compatible for 7-8-9 speed derrailleurs.
    – Kibbee
    May 4, 2016 at 15:08
  • According to Zinn, everyone's 11 speed wheels work fine with each other's rest of drive trains (velonews.competitor.com/2013/09/bikes-and-tech/…) on road bikes.
    – Batman
    May 4, 2016 at 15:20
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    Yeah, a difference of 0.07mm (Shimano vs. Campy) between cog pitch, even over 10 shifts only adds up to 0.7mm of misalignment. The bike should shift just fine in any case. I wonder, if the spacing is so close, why they just didn't all agree on making them exactly compatible. i guess they all developed them in secret at the same time.
    – Kibbee
    May 4, 2016 at 15:32
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    They would all technically be "road". however at the 9 speed level there is really no distinction other than marketing since everything is compatible with everything else. I'm not sure if the mountain riders actually ride up steeper hills (they can get pretty steep in road races), but the terrain combined with the chunkier tires creates more resistance which is why the larger gears are required on the cassette.
    – Kibbee
    May 4, 2016 at 15:38

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