Just like Shimano didn't rush with the release of their Shimano XT M8100 drivetrain, we haven’t rushed this review. 2,000km of testing later...
In this day and age, it’s fair to say that all the best mountain bike groupsets from Shimano and SRAM just plain work. Sure, some are heavier than others and some are a bit clunkier and some don’t offer multiple shifts from a single sweep of a shift lever, but hey, they all work just fine.
What you really want to know, when you’re weighing up what drivetrain stuff to buy, is how well does it last? Well, we’ve put nearly 2,000km of riding into this Shimano XT M8100 drivetrain and feel it’s safe to reach some concrete conclusions.
We’re still using the same cabling. We’re still using the same chain. It all still shifts like it did on the first ride. Actually, that’s not true. It shifts better than it did on the first ride; the first few rides on it were a little bit noisy and ever so slightly snaggy-feeling under shifting. But after a while, like a pair of stiff jeans, everything wore-in a bit and things improved greatly. Improved to the point where we no longer think about it. We can’t even remember the last time we’ve had to twiddle the barrel adjuster to take up some cable stretch. Surely we must have done at some point?
The shifter itself is great. The grippy finned rubber pad on the thumb lever adds a surprising amount of tactility (you really notice its absence when riding other drivetrains). The finger (trigger) lever – which can also be operated with a thumb, but you know what we mean – doesn’t get any rubber, but is still perfectly fine. In fact, the trigger lever has genuinely been the first multi-release lever we’ve not had to treat with caution for fear of mis-shifting. It always does what we want it to (single shift or multiple shift).
We’ve not really had much cause to deal with the rear mech, and it’s survived the rigours of less-than- careful riding just fine. The jockey wheels do a decent job of not holding on to mud. We do like the ability to easily adjust the strength of the clutch via the little rubber-capped porthole.
We sometimes run the clutch on the ’weak’ side of the spectrum for nerdy suspension-affecting reasons, and we’ve not had any issues with dropped chains.
Which brings us on the chainset. Boring-looking but undeniably brilliant performance. The pinch-bolt axle design is the best in the business. The narrow- wide chainring just does its job. It seems to suffer from scuff significantly less than lower-tier Shimano cranks, although it does start to look tatty eventually.
The 10-51t cassette is still working just fine. As is the chain. I’m not meticulous when it comes to post-ride drivetrain maintenance either, so the durability of this stuff is impressive. A word of note: don’t ignore the thin nylon pre-washer that comes with the cassette – if you neglect to install it, the cassette will creak on the freehub under load.
We suppose we now have to talk about how Shimano XT M8100 drivetrain compares to SRAM GX drivetrain for those who like to keep score on the battle of the brands. Well, we’d rather have Shimano XT, but we wouldn’t not-choose a certain bike if it happened to be specced with SRAM GX either. They’re both good. We just feel that XT has the edge when it comes to the tactility of the shifting; it feels like your thumb is directly connected to the top jockey wheel, pushing the chain where it needs to go. It’s a great man-machine feeling that really connects you with your bike.