KMC e12 Turbo and Hyperglide+ (relevant for Wild FS users)

[Gyre]

Just as an FYI for those curious about the KMC 12-speed chain and Orbea Wild FS riders specifically: The KMC e12 Turbo chain that comes spec'd with the Shimano 12-speed cassette and shifter does *not* appear to support the Hyperglide+ function. I switched chains yesterday and went for a test ride. I immediately noticed that the XT 8100 chain was shifting under load in the way I'm used to seeing from Hyperglide+, while the KMC chain shifted "normally" (i.e. it was fine, but not nearly as smooth under load).

To state what is perhaps obvious: This is based on my subjective experiences using the KMC chain for a few weeks and then making the switch to the XT 8100 chain.

 

[Dan63]

I have 12 speed XT (shifter, cassette, chain, derailleur) on my Altitude. Recently fitted a gold KMC X12 chain as the Shimano 8100 chain isn't plated and goes rusty very easily, thought i would try something different and add a little gold bling to match the bike.

I found that the KMC chain is not very well compatible with Shimano 12 speed, had the following issues -
- Jumps down off the largest cogs when wheeling the bike backwards.
- Also jumping off the Powerplay lower idler pulley in the large cogs when wheeling backwards
- Poor shifting in general
- Even when indexed correctly KMC chain would somehow catch teeth on the next gear and jump down a gear momentarily causing a massive crunch. This would happen pedalling under load shortly after changing gears. I managed to "fix" this by adding a few clicks to the barrel adjuster, but in turn would cause noise where the chain would rub in some gears.

On closer examination i found differences in the two chains -
- I measured the dimensions of the chain with a digital gauge. Externally it was the exactly same across the outside of the plates. Internally there is a difference of 0.3mm between the plates when comparing the two.
- The KMC is chamfered on both sides/symmetrical, Shimano only chamfered on the outside plates/asymmetrical and must be fitted in a certain way.

The difference in internal sizing was noticeable - Straight out the box i needed to minus 12-15 clicks on the barrel adjuster to index this chain, it was indexed perfectly with the Shimano prior to switching.

Fitted a new XTR 9100 chain after two rides on the KMC. Back to perfect shifting, no jumping gears, quiet operation. Hopefully the XTR chain doesn't rust!

TLDR; KMC chain not compatible with Shimano HG+, stick with Shimano chains for peak performance. KMC chain is sized and chamfered differently.

 

[Inz]

Very interesting thanks for sharing. I know this is an old thread but bike manufacturers are still fitting KMC chains on Shimano 12 speed Cassettes. One bike shop said they immediately replace KMC chains with Shimano when all other components are Shimano, maybe this is the reason why.