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Compatibility [02] Cassettes

This post will explain bicycle cassette compatibility i.e. what cassettes can be mixed with which rear shifters/derailleurs. For compatibility with various chains, see: Chain compatibility post. Overview of compatibility and possible combinations will be given according to the number of sprockets. From the old 6 sprocket standard to the newest 12 sprocket one. There are two things to consider when combining cassettes: number of sprockets, and sprocket spacing. Both those things affect the cassette width and indexing of non-friction shifters, i.e. index shifters. Table with sprocket thickness and spacing is at the end of this post.

Before you start, to avoid any misunderstanding:
please take the 5 minutes needed to read the compatibility articles use instructions.

Related article: Speeds – rear sprockets.

Indexed shifters work with clicks – each click changes one “speed”. In order to function properly, they require that derailleur movement ratio and sprocket widths are matched with shifter’s cable pull ratio. This is explained in detail in a separate article on shifters: Rear shifter compatibility.

One more thing before explaining compatibility: there are two main standards of cassette mounting. Freewheel and freehub. That is explained in the article: Freewheel vs cassette. 6 speed is always with a freewheel. 8 and more speeds is always a freehub cassette (there used to be 8 speed freewheels, but those where never widespread and are now obsolete). 7 speeds usually come as freewheel cassettes, but can also be found in a freehub cassette standard.

Most manufacturers’ cassettes (and freehub body splines) are compatible with Shimano (SRAM, Sun Race etc.), while Campagnolo cassettes use different freehub splines – that is explained on. Also, SRAM XD cassettes (and freehub body splines) differ from all the rest. All this is explained in Rear hub compatibility post. These mounting standards are important for physical mounting of the cassette on the wheel, they have nothing to do with chain and shifter/derailleur compatibility.

6 speeds

All the 6 speed sprockets are with a freewheel. As a rule of thumb, all the models of all the producers can be interchanged without problems. Shimano’s standard is widely accepted.

Sprockets are placed at 5 mm spacing, with each sprocket being 1.85 mm thick.

7 speeds freewheel

Sprocket width and spacing is the same as for 6 speeds. Here Shimano standard is also accepted and all the producers’ 7 speed freewheels are compatible with it.

Sprockets are placed at 5 mm spacing, with each sprocket being 1.85 mm thick.

7 speed freehub (cassette)

There is an obsolete Shimano Uniglide standard, and a current, Shimano Hyperglide standard. If for any reason you have a Shimano Uniglide cassette, they can be fitted onto a Hyperglide freehub, just the smallest sprocket needs to be replaced with a Hyperglide one.

Uniglide uses threaded smallest sprocket to hold the cassette in place, while the Hyperglide uses a special lockring.

Left are two Uniglide sprockets (bottom one is the smallest, top one is the 2nd smallest) To the right are two Hyperglide sprockets (bottom smallest, top 2nd smallest)
Left are two Uniglide sprockets (bottom one is the smallest, top one is the 2nd smallest)
To the right are two Hyperglide sprockets (bottom smallest, top 2nd smallest)
Front part of the smallest Hyperglide sprocket has small teeth to hold the lockring in place.

All the modern cassettes are of Hyperglide standard, regardless of the teeth number. In case of having a uniglide freehub, mounting a modern (available) hyperglide cassette can be done in two solutions. One is to remove smallest sprocket off the (new) hyperglide cassette and use the (worn) smallest uniglide sprocket as a lockring, filing/grinding off the widest spline of the rest of the (new) hyperglide sprockets. More complicated (probably better) solution is to switch the freehub body for a hyperglide one. Video explaining it is here: converting an uniglide freehub to a hyperglide.

This goes for 8 speed as well: 7 speed cassettes have the same sprocket width as 6 and 8 speeds, but 8 speed is a bit tighter spaced – at 4.8 mm. This means that 8 speed sprockets can be used for 7 speed cassettes, as long as the 7 speed spacers between sprockets are used.

Many cassettes have sprockets held together with 3 small rivets, but these are only for convenience when mounting and can be removed so that sprockets can be swapped.

8 speeds

The same sprocket width as with 6 and 7 speeds, but a bit tighter spaced – at 4.8 mm. This means that 7 speed sprockets can be used for 8 speed cassettes, as long as the 8 speed spacers between sprockets are used.

Sprockets are placed at 4.8 mm spacing, with each sprocket being 1.85 mm thick.

Campagnolo 8 speed cassettes have just slightly different sprocket thickness and spacing, compared to Shimano, so they can be mixed with Shimano 8 speed shifters and derailleurs, with index shifting working good. Provided that appropriate freehub body is used: Campagnolo and Shimano cassettes can’t fit each other’s freehubs – Campy with Campy, Shimano with Shimano.

9 speeds

Here there is no combining with any other standard. 9 speed cassettes have a unique sprocket thickness and spacing. Campagnolo has their own 9 speed standard, incompatible with Shimano’s.

Sprockets are placed at 4.35 mm spacing, with each sprocket being 1.78 mm thick.

10 speeds

Same sprocket width as 11 speeds, so (more expensive) 11 speed sprockets can be used as replacement, provided 10 speed spacers are used,.

Sprockets are placed at 3.95 mm spacing, with each sprocket being 1.6 mm thick.

This doesn’t go for Campagnolo. Campy 10 speed is only compatible with Campy 10 speed because of different mounting, so an individual Shimano compatible sprocket can’t be mounted.

11 speeds

Sprocket width is the same as for 10 speeds, so 10 speed sprockets can be used, provided that 11 speed spacers are used.

Sprockets are 1.6 mm thick, spaced at 3.74 mm (road), or 3.9 mm (MTB).
For more clarity on this, see below the comment by Nicolas Hanssens and the following four replies by myself and Nicolas Hanssens. I.e, based on my last measurement, and practical experience, Shimano MTB and road 11-speed cassettes have very slight differences that don’t make a noticeable difference when it comes to shifting (video explaining an 11-speed MTB cassette on a road bike pairing).

Campagnolo of course doesn’t accept any 10 speed sprockets. However, just like with 8 speeds, combining complete cassettes is possible: Campagnolo 11 speed cassettes have just slightly different sprocket thickness and spacing, compared to Shimano, so they can be mixed with Shimano 11 speed shifters and derailleurs (and vice versa), with index shifting working good. Provided that appropriate freehub body is used: Campagnolo and Shimano cassettes can’t fit each other’s freehubs – Campy with Campy, Shimano with Shimano.

With 11 speeds there is another exception: it is the only case where Shimano standards for road and MTB differ. For all the other standards, MTB and road cassette is just a marketing term, explaining the number of teeth bigger sprockets have and the difference in sprocket teeth numbers between adjacent sprockets, but with 11 speeds, cassettes really differ. 11 speed road has a longer freehub body, while MTB 11 speed cassette fits 8-9-10 speed freehub. However, sprockets, except the largest one, can be mixed and matched.

Also, SRAM makes XD 11 speed MTB cassettes that fit only SRAM XD freehubs, they can’t be mounted onto other freehub types. These cassettes can accommodate a small sprocket with only 10 teeth.

Update of summer 2018: Shimano introduced new Hyperglide+ cassette standard. These come as 11 and 12 speed cassettes. They require a special freehub body (with different spline design called “Micro Spline“), as well as a special Hyperglide+ chain. The same chain is used for both 11 and 12 speeds, but works only with Hyperglide+ cassettes. Also, derailleurs and shifters of other standards won’t work. Smallest sprocket has 10 teeth.

12 speeds

These come in four different standards.

  • First one is SRAM MTB XD. These are compatible with SRAM XD 11 speed freehubs. Smallest sprocket has 10 teeth.
  • As of mid-2018, SRAM has introduced NX Eagle groupset, that includes 12 speed cassettes compatible with Shimano (and SRAM) standard freehubs (for 8, 9, or 10 speed cassettes). However, they don’t allow for the smallest sprocket to be smaller than 11 teeth.Sprockets are spaced at 3.65 mm, with the smallest two placed slightly more apart to accommodate for crossed chain when using a crankset with only one chainring.
  • Shimano Hyperglide+ 12 speed MTB cassettes, compatible only with Hyperglide+ chains and Hyperglide+ freehubs (using Micro Spline mounting system). Smallest sprocket has 10 teeth.
  • In 2018, Campagnolo also jumped on the “more-speeds” bandwagon, introducing their 12 speed groupsets. Campagnolo 12 speed cassettes fit their (Campagnolo) 11 speed freehubs.

One exception: Shimano Dura Ace from year 1984 to 1996 (6 to 8 speeds)

Compatible only with Shimano Dura Ace shifters and RDs from the same period (6, 7 and 8 speeds), because of a different cog pitch.

Campagnolo Exa-Drive and Ultra-Drive

Campagnolo cassette standards. Left: Exa-Drive Right: Ultra-Drive
Campagnolo cassette standards.
Left: Exa-Drive
Right: Ultra-Drive

Stamped circle is just an indicator helping proper alignment when mounting sprockets. No mechanical function whatsoever.

Indented grooves are used to pick the chain up when shifting to a larger sprocket. Exa-Drive indentations are designed to catch the chain pin first, then the outer plate. They work well with 8 and 9 speed Campagnolo chains.

Modern 10 and 11 speed Campagnolo chains don’t have pins protruding out of outer plates, so the newer Ultra-Drive is designed to catch the outer plates directly.

Sprockets of these two standards (with equal number of speeds) can be combined, although it will affect gear changing speed.  🙂

Table of sprocket spacing and thickness:
For a full chart including spacer thickness, total cassette width, freehub mount standards etc, see – bicycle cassette standards post.

CassetteCassette pitchSprocket thickness
All 6-speed5 – 5.51.85 – 2
All 7-speed51.85
Shimano 8-speed4.81.8
Shimano 9-speed4.351.78
Shimano 10-speed3.951.6
Shimano 11-speed road *3.74 *1.6
Shimano 11-speed mtb *3.9 *1.6
Campagnolo 8-speed51.9
Campagnolo 9-speed4.551.75
Campagnolo 10-speed4.151.7
Campagnolo 11-speed3.851.6
SRAM 8-speed4.81.8
SRAM 9-speed4.351.8
SRAM 10-speed3.951.6
SRAM 11-speed road3.741.6
SRAM 11-speed mtb3.91.6
SRAM 12-speed mtb3.65n/a
Shimano Dura Ace 6 speeds6.07n/a
Shimano Dura Ace 7 speeds5.52n/a
Shimano Dura Ace 8 speeds5.3n/a

* See the explanation in chapter 11.

Compatibility posts are also available in eBook (printable and Kindle) and paperback editions on Amazon:

Bicycle drivetrain compatibility book
Bicycle drivetrain compatibility book

53 thoughts on “Compatibility [02] Cassettes”

  1. Pozz Relja; nasao sam jeftino treking biciklo sa manje ostecenja. Treba zamjeniti zadnju felgu i cijeli srednji pogon zajedno sa BB. Oprema je pozadi alivio 8 brzina. Problem je sto sam kupio felgu sa 9 brzinskom kasetom; je li moguće prebaciti kasetu? I drugo pitanje; kad vec mijenjam stavio bih Hollowtech pogon; nasao sam fc 470 za 30e i pise da mu je duljina 121 mm; moj bb cetvrtaljka je 122mm?

  2. Hey guys,
    i wonder if I could use any 11 speed cassette on my sunringle SRC hub. Can you help me by telling me a model of such cassette?
    Thanks in advance! Cheers!

  3. Hello Relja,

    Thank you for putting up so much information, really appreciate it.
    I had a couple of question that I’d really appreciate if you would answer.
    Firstly, I have a Decathlon Triban RC 100, Flat bar with a 12-28t Microshift cassette and 44t crank, nothing fancy and I ride mostly in the hills. So, is it better to go for say a 11-46t cassette or a small 36t crank for climbing easier? If both, where will I notice the most difference?
    Secindly, I have figured from all the reading that I can go for a 10 speed, 11-46 Deore cassette on my road bike, but I will require a Deore derailleur and a Deore shifter. Is that correct or do I have other options?
    Thanks in advance and stay safe!

    • Hi,

      Short answer:
      I’d find some, new or used (2nd hand), friction bar-end shifters, triple road cranks (30-39-50) and a triple road front derailleur, while keeping the RD and the existing cassette.
      For the really low gearing, using friction shifters, one could also use MTB triple cranks with an MTB triple FD (22-32-44 and similar).

      If the frame has housing stops for the FD (since it’s a 1x as far as I know), or if those can be mounted (depending on the tubing design, that can be more or less of a hassle). If not, then a more expensive, higher quality 1x drivetrain will be needed. Probably costing more than the whole bike when it’s new.

      Other options may end up being less good or at least more expensive for good quality with a wide range.

      Longer answer:

      There are dozens of options – and the choice depends on one’s budget, criteria, priorities etc.
      It boils down to using friction shifters or, if going with indexed shifters, making sure that the derailleur(s), shifters and cassettes/chainrings are all matched to work with each other.
      (friction vs indexed shifters)

      Road RDs can be fitted with a longer hanger to accommodate for larger cassette sprockets – as shown in this video:
      Pairing Shimano 11speed MTB cassette with a road groupset

      If using 10-speed MTB RD (like 10-speed Deore), you’d need a matching shifter.
      For up to 9 speeds, Shimano MTB and road shifters and derailleurs are compatible (older generation 9-speed Deore RDs for example work fine with up to 9-speed road shifters), but the shifter’s number of speeds still needs to match the cassette, of course.

      There are practically dozens of different permutations of those components, with different models and numbers of speeds – and they work fine when they are matched (pull-ratios, number of speeds etc.).
      That’s why I’ve made a series of articles in this compatibility section – so everyone can see what their choice is, depending on what’s available and their other criteria.

      I like cheap and robust – so I choose double or triple chainrings, paired with friction shifters. This gives me a wide range of gearing (low enough for long, steep climbs, as well as high enough for the wind at my back on the flats). 7-speed cassettes (and chains for that matter) are more than enough for me when paired with triple cranks – while friction shifters let me go with practically any RD I get a hold of.

      Unlike triples, 1x systems (only one front chainring) require a huge gearing space to be covered by the cassette alone (1x systems pros and cons).

      So with the Triban 100, you’ll need to decide: changing the cranks, adding a FD and a front shifter, or looking for a greater-range cassette.
      When it comes to the cassette, unless your existing shifter is friction-shifter, you’ll need a new shifter for anything except 7-speed cassettes (if that’s what’s on the bike).

      Another problem is that 10+ speed MTB RDs require MTB shifters (generally speaking) – and those shifters can’t be really elegantly mounted on drop-bars.

      When it comes to which gearing choice is better – this online gear calculator is a great tool, so you can see for yourself.

      I personally find 36T cranks to be a bit too small for the flats – even with 11 teeth at the back.
      For the long and steep climbs, on the other hand, 36T is a lot better than 40 or more, especially with the “normal” cassettes that go to up to 34 teeth (the ones that are not rare, expensive and look like a big plate 🙂 ).

      The only practical way to make 1x drivetrain be versatile enough is to have a cassette with a huge range – which is costly if going with indexed road bike shifters (STI levers) and a matching RD. Cassettes and chains are also more expensive (wide-ranged 10, 11 or 12-speed cassettes).

  4. Concerning 11 speed spacing:
    “Sprockets are 1.6 mm thick, spaced at 3.74 mm (road), or 3.9 mm (MTB). ” Where did this specification come from?

    I’m asking this as I’m converting a bike to 11-speed and considering my cassette options. Given the road freehub is 1.8mm wider, I’m leaning towards a CS-HG700-11 cassette which has the removable 1.8mm spacer to allow install on a 8-9-10 HG Freehub. I may have spoke clearance issues, but the investigation into compatibility has lead me down the rabbit hole of looking closer at Shimano road vs. mountain 11-speed cog pitch.

    If you look up the Shimano parts manual the XT cassette (CS-M8000) and a Durace Cassette (CS-9000) they both list a 2.18mm thick spacer. I have both of these cassettes and the CS-9000 spacer measures 2.14mm and the CS-M8000 measures 2.24mm. This could be manufacturing tolerance. IDK

    I have these two cassettes and took several pictures side by side. I removed the small cogs to the first 2.18mm spacer and placed them side by side. I did this in a few configurations. See the pictures here. In two images there appears to be a small stack height difference but I believe that to be due to camera angle. Most of them the sprockets look aligned. In the one that looks misaligned, if 3.74 and 3.9 mm pitch held, the difference across the 8 cogs shown would be 1.28 mm. If you use the cog thickness as reference the difference is much smaller. This with the other pictures lead me to believe they are the same.

    Based on these results I’m lead to believe the pitch between a road and MTB 11 speed cassette is the same. Your real world results ( seem to back this up. I have measured several cogs on both cassettes and they are both 1.6 mm thick as you state. This would lead me to conclude they both have a pitch of 3.78 mm.

    I would also point to Shimano’s GRX web page which list both Road and MTB cassettes as compatible with this group.

    Do you have any explanation of the evidence I have that would still conclude the road and mountain Shimano 11 speed cassette to have a different cog pitch?

    • Hi Brain,

      The cassette pitch given is a calculated average after measuring the entire cassette width
      – cassette width, minus one sprocket width (half for each side, to get the distance from middle to middle of the smallest and largest sprocket)
      – divided by the number of sprockets reduced by one (with / (sprocket count – one) )

      My first hand experience and following measurements seem to show that Shimano 11-speed road and MTB cassettes are (virtually) identical (too little difference to make a difference).
      I.e. my last measurement results show 3.84 mm for the road, and 3.93 mm for the MTB cassette.

      If what you say for the GRX is true (no doubt – just at this moment the page says “maintenance”), that means Shimano implies they are identical for all practical purposes.

      I’ll edit the article with a note that whatever the exact measures and pitch are (not sure how to measure it accurately in a more “direct” way), the cassettes can be mix-matched for all practical purposes.

  5. Thanks for the info. I’ve seen the 3.74 and 3.9 floating around the internet. Perhaps they got it from you :). I’ll have some more accurate measurement tools available to me later this year so I’ll see if I can come up with anything better. I feel like short of 3D blue light scanning and 3D modeling, we will never know.

    I’m also curious if maybe it’s not 100% even. IDK. It’s hard to measure across the carriers. I’ve come up with 3.8 – 3.85 as well. I don’t think my calipers are that accurate so I’ll take it with a grain of salt. I’ll have some larger micrometers available soon so I’ll measure again.

    I’ve noticed the cogs on the carrier of my XT cassette are thicker than the Dura Ace cogs. Especially the 40t. The Dura Ace cogs seem more consistent. This makes comparing the two hard. That’s why in the pictures I compared the smaller cogs and they seem more consistent.

    This is becoming academic. I agree that for all practical purposes they are interchangeable.

    I can say for sure that my CS-M8000 11-40 11sp XT cassette on my 8 speed Dura Ace wheel (130mm spacing) works in the smallest cog without hitting the frame of my 2000 Cannondale XR800 and clears the spokes in the 40 by a large margin. This seems to give me an upgrade path to 11 speed with an CS-HG700-11 Cassette and 11-speed shifters and GS rear derailleur. It uses a removable 1.8 mm spacer for MTB HG compatibility (or older road 8,9 hubs). Good food for thought for anyone looking to upgrade an older bike. This bike has 1996 Dura Ace which leaves few options to replace worn parts. I was glad to see your video and comments on your mismatch of road and mountain with no issues after one year. This gave me confidence to move forward.

    I’m glad I found you. Thank you Google.

    • I got some more precise (digital) callipers, but I don’t do any re-measuring, until I see something being off – as was/is the case with the 11-speed cassette compatibility.

      The whole compatibility series of articles was written for my own convenience – with a constant shortage of parts and money in my country and always mix-matching. The main reason for translating it into English was to more easily answer frequently asked questions and for “why not” reasons. 🙂

      However, judging by the number of comments, it seems that a lot of people are having the same dilemmas and problems, so it ended up being a lot more useful than expected.

      It’s understandable that bike companies have both financial and legal reasons to keep their “official” recommendations a lot more “conservative,” but it does make one’s life a lot more difficult when mix-matching, instead of buying a whole new groupset.

  6. Re: 11s MTB pitch…

    For the record, one should keep in mind that those black aluminium sprockets on 11-speed MTB cassettes are thicker than the steel ones (about 2 mm vs 1.6 mm). That could throw off the calculations a bit.

  7. I have a cyclo cross bike with an 11 speed SRAM PG-1170, 11-36, road cassette paired with a SRAM force rear mech. I’ve been wanting to fit a pair of wheels on this bike from a 29er mtb with DT Swiss 240 MTB Hubs with a 10/11 speed freehub body fitted. I hadn’t appreciate all the complexity with 10/11 speed compatibility between road and MTB and found this blog and the comments really useful.

    I didn’t want a huge 11 speed MTB cassette with a 50 sprocket (all the Shimano and SRAM 11 speed MTB cassettes all seem to have a 48 or 50 sprocket) as that isn’t ideal for cyclocross or gravel and a Shimano or SRAM 11 speed road cassette won’t fit the freehub as these cassettes are too wide.

    My solution has been to use a Sunrace CSMS8 cassette. These are 11 speed MTB cassettes and for the mtb 10/11 freehub but you can get an 11-36 which is much better for the cyclo-cross/gravel bike.

    In terms of spacing of sprockets I have compared the SRAM road cassette and the Sunrace MTB cassette and I can’t tell any difference in width, although it’s quite hard to measure precisely. Visually, all the sprockets line up. Gears run smoothly, even under load

    Hopefully others will find this useful



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