Why can't we buy individual cassette gears? Probably 90% of my riding is on just 4 to 5 of the gears on the cassette. The rest of the gears are used much less. I have a X0 SRAM derailleur 9 speed set up. Since I need to replace the chain and cassette very soon I'd like to swap for a 10 speed set up. Other than cassette, chain and shifter will I have to replace the derailleur and the rings?


  • This is something that only manufacturers can answer. – Móż Nov 22 '15 at 5:48
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    Also, one question per question please. – Móż Nov 22 '15 at 7:12
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    If you are only using 4-5 of the gears then why do you want to swap for a 10 speed? – paparazzo Nov 22 '15 at 10:59

A long time ago some bike shops stocked single cogs, but that was when there were 5 speed cassettes and few choices. Back then few people seemed interested. Today with 6,7,8,9,10,11 speed options, three major manufacturers, often with multiple materials in each width as well as other variations, there would be too many options. I suspect even the really big online shops would struggle. For comparison, look at spokes - few places stock more than the most common types in the most common sizes, let alone 2mm increments from 100mm to 400mm (Rohloff 16" wheel to front 36" wheel)

Think about what's required: you want a replacement cog for the particular cassette you have, out of at least 10 options for your particular combination of manufacturer, number of cogs, material and cost. Sure, you would probably accept a cog out of the next step up or down in the manufacturers range, as long as it was compatible (hint: it probably isn't).

Look online: Wiggle have 84 cassettes listed, ChainReaction have 69 MTB and 56 road cassettes, Starbike have 80 options. Assuming they average 9 cogs per cassette and 20% are duplicates/compatible, that's over 400 different cogs to stock.

(too long for a comment).

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    That being said, some bike shops will disassemble cassettes to some level and rebuild them (Harris cyclery is one), doing custom combinations. – Batman Nov 22 '15 at 15:24

Shimano stopped selling disassembleable cogs when they moved to Hyperglide. With Uniglide you could build up your own cassettes and even flip the direction of a cog to wear out the other side of the teeth. I've heard a number of reasons for this, but ultimately I reckon it's to sell more cassettes.

Depending on your derailleur you will likely also need to replace that. Typically they work down (i.e. 10-speed derailleur on a 9-speed cassette) but not up. This is because the cable pulls are the same, but the geometry is different because of the narrower cassette and extra cog.

You do not need to replace anything on the front, unless you're running some super chunky chainrings that won't fit on a 10-speed chain.

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    I doubt its to sell more cassettes, but just that its more expensive for everyone involved. Shops have to keep stock of the different cogs, you often have to pay someone to put together the cassette, Shimano has more overhead to have separate SKUs and for smaller spacings, it will be harder to put together. Most gear ranges (esp. now with so many gears) are well represented already, so the custom angle is less valuable now than in the cog swapping days. And if you wear out a few gears, I'm not sure how many times you'll take apart and put back together with the old gears which are still good. – Batman Dec 10 '15 at 1:19

You might want to swap to a 10 speed for the same reason there are 11-speed cassettes available nowm where as long ago we had only 5 speed cassettes.

Smoother, less-jumpy shifting.

  • Gidday and welcome to SE Bicycles, Thank you for your answer - I have edited it to remove the restatement of the question. If I have changed the meaning at all please revert. – Criggie Dec 9 '15 at 0:58
  • I was just responding to Frisbee's comment/question/response as to the obvious reason why someone would make this swap. – jeff Dec 9 '15 at 5:25
  • They will likely also need a new rear wheel if they opt for an 11 speed setup due to freehand width change that was introduced with 11 speed. – Rider_X Dec 9 '15 at 8:22
  • @jeff Fair enough. Here on this stack, every answer is an answer to the original question. Just focusing on the answer. – Criggie Dec 9 '15 at 8:39

Most modern cassettes now are not only just individual cogs and spacers. They often have carriers for large cogs or have many of the larger cogs and their spacers bolted together. I think a big reason for this is the adoption of aluminium freehub body for weight saving. They cannot withstand as much force as steel freehub bodys without deforming and basically require cassettes be more connected on the medium and higher torque gears.

Additionally, it's difficult to tell when cogs are worn. It's not easy to measure them like you measure chain wear as well as tighter tolerances between cassette cogs on 9-10-11 speed bikes making it more difficult to sell single parts of a cassette and ensure good shifting. It's much easier for a bike shop (or home mechanic) to replace the entire cassette and chain together to ensure a smoothly operating bike.

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