Shimano’s 12-speed chains are optimized for downshifting and have a smaller inner width than normal. Subsequently, the chain has a hard time grabbing chainrings that aren’t compatible with Shimano’s HG+ system. In some cases, the chain gets stuck and fails to move along the chairing.
Having said that, some combinations could work, especially if one replaces the Shimano quick link with a SRAM or KMC one.
Chain Width
A chain is made of inner and outer plates. The distance between the inner plates is known as inner chain width whereas that between the outer plates is the outer chain width.
Normally, the inner width of a chain does not change. However, chains get thinner with every gear increase.
For example, 11-speed chains are thinner than 8-speed chains. The purpose behind this engineering is fairly simple – the cogs on an 11-speed cassette are closer together.
Or in simpler terms, cassettes with more speeds are “denser”. As a result, the chain has to get thinner, or else it will rub against the cogs surrounding it. The outcome will include poor shifting, pre-mature drivetrain wear, and excessive noise.
For that reason, the thickness of the outer plates diminishes with every gear jump.
The downside is that the chain gets weaker. Hence why single-speed chains are so thick and strong whereas multi-speed chains are thinner and less robust.
Shimano’s 12-speed Chains Are An Exception
Shimano’s 12-speed chains are optimized for downshifting and shifting under load. To achieve this effect, the chain has customized inner plates and subsequently its inner width is narrower than expected.
Thus, Shimano’s 12-speed chains operate poorly with 11-speed chainrings. The chain is simply too narrow to grab the teeth of the chainring.
Shimano 12-speed Chains and SRAM Chainrings
In general, it’s not recommended to combine a SRAM chainring with a 12-speed Shimano chain unless it’s explicitly specified that the chainring is compatible with a 12-speed Shimano HG+ chain. (e.g., SRAM Oval Boost DM Chainring).
That said, some people “hack” the Shimano 12-speed chain to get it working with other brands by replacing the quick link (the narrowest point) with a KMC or a SRAM one.
Once that’s done, the chain is very likely to offer somewhat acceptable compatibility with wider chainrings.
The downside of this method is that it causes drivetrain wear and noise.
12-speed Shimano HG+ chains have inner plates with extended inner links which tend to grind against the teeth of chainrings that aren’t HG+ compatible.
Hence why this hack is not recommended when longevity and top-level performance are the ultimate goal.
FAQ: My bike has SRAM cranks. What chainring do I need to combine them with a Shimano 12-speed chain?
You will have to search for a chainring compatible with SRAM cranks and Shimano’s 12-speed chains.
Some of the possible options are:
- SRAM Oval Boost DM Chainring –
- The Wolf Tooth chainring made specifically for Shimano HG+.
- ethirteen SL GUIDERING (post 2019 models)
FAQ: Can I use a Shimano 12-speed Chain With a SRAM Cassette?
Technically, a SRAM cassette can work with a 12-speed Shimano chain. However, the combination doesn’t provide the benefits offered by Shimano’s 12-speed drivetrains.
12-speed Shimano chains and cassettes are designed to work in conjunction to optimize shifting under load. For that reason, the cassette has special ramps making it possible to switch gears without easing off the pedals which is the standard way to shift.
By combining the chain with a SRAM cassette which will undoubtedly have a different design, one eliminates the benefits of using a Shimano 12-speed chain.
Summary: What You Need To Know
- Shimano 12-speed chains work best with chainrings listed as HG+ compatible.
- A Shimano 12-speed chain can work with a 12-speed SRAM chainring if the quick-link is replaced with a SRAM or KMC one. The downside of this approach is that the drivetrain will be louder and wear out faster as there’s extra contact between the teeth of the chainring and the inner plates of the chain.
- The main goal of Shimano 12-speed drivetrains is to make it possible to shift under load. This is achieved via a new design of the cassette and the chain. The chain is narrower than other 12-speed models and has extended inner plates whereas the cassette has special ramps not present on other brands.
- For optimal performance, it’s advisable to stick with the components part of the family.
