Short answer: a chain must match the number of sprockets on your cassette, because each speed step uses a narrower chain. Up to 11-speed, chains from Shimano, SRAM, KMC and Yaban are broadly interchangeable. At 12-speed they are not, and SRAM's Flattop chain used on AXS road groupsets works with nothing else.
Contents
- Speed means width
- Chain width by speed
- Mixing brands: where it works and where it stops
- SRAM Flattop and other exceptions
- Quick links must match the speed
- Directional chains
- Getting the length right
- Single speed and internal hub chains
- Frequently asked questions
Speed means width
Cassettes have grown from 6 sprockets to 13 without the hub getting meaningfully wider. The space had to come from somewhere, so sprockets moved closer together and chains got narrower.
Two dimensions matter, and only one of them changes:
- Pitch is always 1/2 inch on every derailleur bicycle chain, from a 6-speed hybrid to a 13-speed gravel bike. This is why chainrings and sprockets are broadly interchangeable across speeds.
- External width narrows with every speed step. This is what determines compatibility, and it is the number that must match your cassette.
Fit a chain that is too wide and it will rub adjacent sprockets and shift badly or not at all. Fit one that is too narrow and it can drop between sprockets or sit unstably on the chainring teeth.
Chain width by speed
| Speeds | Approximate external width | Notes |
|---|---|---|
| Single speed, internal hub | 1/8 inch or 3/32 inch | See the single speed section below |
| 6, 7, 8 | 7.1 to 7.3mm | One chain covers all three |
| 9 | 6.5 to 6.8mm | |
| 10 | 5.85 to 6.2mm | |
| 11 | 5.5 to 5.6mm | Road and MTB chains differ slightly |
| 12 | 5.25mm | Brand specific, see below |
| 13 | 4.9mm | Campagnolo Ekar only |
The 6, 7 and 8-speed row is genuinely one chain. If you have an entry-level hybrid or an older mountain bike, any 6 to 8-speed chain will fit whichever of the three you have.
Chains sit in chains, and matching cassettes in cassettes.
Mixing brands: where it works and where it stops
Up to and including 11-speed, chain brand is largely a question of budget rather than compatibility. Shimano, SRAM, KMC, Yaban and others all make chains to the same width for a given speed, and they work on each other's drivetrains.
| Speed | Cross-brand | Practical position |
|---|---|---|
| 6 to 8 | Yes | Any 6 to 8-speed chain |
| 9 | Yes | Any 9-speed chain |
| 10 | Yes | Any 10-speed chain |
| 11 | Mostly | Works across brands; Campagnolo 11 is best kept to Campagnolo |
| 12 | No | Match the groupset brand and type |
| 13 | No | Campagnolo Ekar only |
Twelve speed is where the old habit of buying whatever chain is cheapest stops working. Shimano, SRAM road, SRAM mountain and Campagnolo all took different approaches, and their chains are not drop-in replacements for each other.
SRAM Flattop and other exceptions
SRAM Flattop is used on 12-speed AXS road groupsets, including Red, Force and Rival AXS. It is not simply a narrow chain. The plates are taller and shaped differently, and the roller dimensions differ from a conventional chain. Only a SRAM Flattop chain works on a Flattop drivetrain, and a Flattop chain will not work on anything else. If your bike has a 12-speed SRAM road groupset with electronic shifting, this is the chain you need and there is no alternative.
SRAM Eagle 12-speed mountain chains are a separate thing again, and are not interchangeable with Flattop.
Shimano 12-speed uses Hyperglide+ chains, which are designed as a system with Hyperglide+ cassettes and chainrings. They will physically fit other 12-speed setups but you lose the shifting behaviour they were built for.
Campagnolo 12 and 13-speed chains are proprietary. Ekar, at 13-speed, uses the narrowest chain in general production.
The rule at 12-speed and above: identify the exact groupset before buying, not just the number of sprockets.
Quick links must match the speed
A quick link is speed specific in the same way the chain is. An 11-speed quick link will not close correctly on a 12-speed chain, and using the wrong one is a chain failure waiting to happen.
Reusability is the part most riders get wrong:
- Up to 10-speed, most quick links are designed to be opened and closed repeatedly, which makes chain cleaning far easier.
- At 11 and 12-speed, most manufacturers specify single use. Shimano and SRAM both state their 11 and 12-speed links should be replaced once removed.
Buy spares when you buy the chain. A quick link costs very little and being without one on a Sunday is what turns a five minute job into a lift home. Link pliers make opening and closing them straightforward, and a chain tool rated to 12-speed is needed for sizing.
Directional chains
Most chains can go on either way round. Several modern ones cannot.
Shimano 12-speed and SRAM Flattop chains are directional, with a designated outward-facing side, usually marked by the brand logo or an arrow on the outer plates. Fitting one backwards degrades shifting and accelerates wear, and it is an easy mistake because the chain will run.
Check the packaging before fitting. If the chain has any printing on one side of the outer plates only, treat it as directional and put that side facing outward.
Getting the length right
A new chain is supplied longer than any bike needs and must be cut to size.
The standard method for a derailleur bike: run the chain over the largest chainring and the largest sprocket, bypassing the rear derailleur entirely, bring the ends together and add two links, then cut.
Alternatively, if the old chain is not stretched beyond use, lay the new chain beside it and match the link count exactly. This is the fastest method and the least error prone, provided the drivetrain was previously correct.
Getting it wrong in either direction causes problems. Too short risks tearing the rear derailleur off when shifted into the largest sprocket and largest chainring. Too long allows the chain to slap and shift poorly in small-small combinations.
Single speed and internal hub chains
Without a derailleur, the chain does not need to flex sideways, so it can be wider and stronger.
| Chain | Suits |
|---|---|
| 1/2 x 1/8 inch | Track, fixed gear, BMX, single speed with a wide cog |
| 1/2 x 3/32 inch | Single speed conversions using derailleur-width cogs, internal hub gears |
The number that matters is the cog, not the bike. A track cog is 1/8 inch and needs a 1/8 inch chain. A single speed built from a derailleur cassette cog is 3/32 inch and needs the narrower chain. A 1/8 inch chain on a 3/32 inch cog will run but sits loosely and can drop.
Frequently asked questions
Can I use an 11-speed chain on a 10-speed cassette?
It will physically run, but do not do it as a permanent fix. An 11-speed chain is roughly 0.4mm narrower than a 10-speed one, so it sits less securely on the sprocket teeth and on the chainring. Shifting becomes less precise, the chain can skip under high load, and it accelerates wear on a cassette that was designed for a wider chain. As a way home it is fine. As a purchase it is a false economy.
Are quick links reusable, or single use?
It depends on the speed. Quick links up to 10-speed are generally designed to be opened and reclosed many times, which is what makes them useful for cleaning. At 11 and 12-speed, both Shimano and SRAM specify single use, because the tighter tolerances mean the link loses grip after being opened. Reusing one is a real failure risk under load. Keep a spare in your saddle bag and replace rather than reuse.
Does a more expensive chain actually last longer?
Sometimes, but not proportionally, and not for the reason most people assume. Premium chains are usually lighter and shift marginally better, achieved by hollow pins and cut-away plates, and those changes do not extend life. What does extend life is surface treatment, and some mid-range chains with hardened or coated pins outlast flagship ones. In Indian dust and monsoon conditions, cleaning and lubrication habits affect chain life far more than the price of the chain does.
Can I use a KMC or Yaban chain on a Shimano or SRAM drivetrain?
Yes, up to 11-speed, and it is a sensible way to reduce running costs on a bike that gets through chains. Match the speed and the chain will work correctly on any brand of drivetrain at that speed. At 12-speed the position changes, because Shimano Hyperglide+ and SRAM Flattop are system-specific designs rather than generic widths, so check that any third-party 12-speed chain explicitly states compatibility with your groupset.
What is the difference between a 1/8 inch and a 3/32 inch single speed chain?
The internal width between the plates, which must match the thickness of the cog. A 1/8 inch chain suits track, fixed gear and BMX cogs, which are thicker and stronger. A 3/32 inch chain suits single speed setups built from derailleur components, where the cog is the same thickness as a cassette sprocket. Running the wider chain on a narrower cog leaves the chain sitting loosely with lateral play, which risks it dropping under load.
Not sure which chain you need?
Send us your groupset name and the number of sprockets on WhatsApp and we will tell you exactly which chain fits. If you are also wondering whether your current chain has reached the end, our guide to telling when a chain is worn covers measurement and replacement intervals.
