It's arrived fashionably late to the party... and it's turning heads already

Product Overview

Shimano XT M8100 Groupset


  • Sweet, instantaneous shifting. Superb cranks. Build quality.


  • Brake inconsistency is a huge fly in the ointment. Could have more design flair.


Shimano XT M8100 groupset review


Price as reviewed:


For better or for worse Shimano has not panicked or rushed Shimano XT M8100. It has taken its sweet time. And the result of that sweet time is this.

Shimano XT M8100 groupset need to know

  • Shimano XT M8100 goes 12-speed with 10-51 or 10-45t Hyperglide+ cassettes
  • Single-ring option with narrow-wide chainring or double chainset with front derailleur
  • New Deore XT shifter with Multi-Shift and two-way release
  • Two-bolt cranks with direct mount chainrings
  • New brake levers brace against the bar for extra stiffness

Shimano XT M8100

In the mountain bike market, Shimano has been off the pace of late. For a brand used to dominating the market, it has recently found itself in second place behind SRAM and its all-conquering Eagle single-ring wide-range drivetrains.

Even though Shimano has a strong fanbase among long-serving mountain bikers, there’s no escaping the fact that its drivetrains were basically dumped by bike industry at OEM level when Eagle came out. Of the bikes that crossed mbr’s path for test in 2018, around three-quarters of them had SRAM drivetrains. Ten years ago, Shimano would have held sway, albeit not to the same startling degree as SRAM’s recent dominance.

Shimano XT M8100

Shifters offer a sensation of absolute control

The question is not really whether it works or not. It’s got Shimano written on it; it’s pretty much guaranteed to work. The question is, is it better than Eagle? Is it too little, too late? It’s not overstating things to say that, if the new Shimano XT M8100 isn’t good enough, Shimano’s ranking in the mountain bike world is at risk of slipping irretrievably further down.

Well, the Shimano family can relax. For now.

Two-bolt arrangeent is the crankset MVP

I’m going to cut straight to the chase here. If I had a SRAM Eagle bike, I’d stick with SRAM. If I was looking at a mountain bike blank slate, I’d go with new Shimano XT. Price-wise, it’s swings and roundabouts. Some new XT bits cost more than it’s SRAM GX Eagle equivalent, some cost less.

New XT shifts faster with more feel and feedback than SRAM GX Eagle. GX Eagle feels flexy and not as instantly reactive when coming off a bike with new Shimano XT. So too, to a lesser degree does Shimano SLX.

Drab componentry an indicator of Shimano opting for function over form

It’s the responsiveness of new XT that is the real takeaway here. Responsiveness combined with a level of human-machine interaction that is intensely pleasing and satisfying. When operating the shifter, it feels like your thumb is directly pushing the jockey wheel across the cassette. It feels likes you can feel what the rear mech is feeling. Man, it is so satisfying. It’s something that makes you feel more at one with your bike. Never a bad thing.

You need to bear in mind that this testing has taken place throughout a UK winter – a Northern England Pennine winter at that. The gears have no right to be as quick and accurate as they have been. Even during the latter parts of rides where gritty puddles have long-rinsed the lube off the chain, these gears just kept on clicking, shifting and whirring away. Other drivetrains at least have the decency to add a bit of delay and graunchy sensation when shifting to smaller sprockets. Not new XT. Click, click, clickety click.

Brakes are still a hit and miss affair

The one-tooth larger gearing range (10-51t versus SRAM’s 10-50t) is all but undetectable on the trail in my opinion, but I appreciate why Shimano had to do it. Simply coming out with a 50t cassette would have overtly felt like just catching up with SRAM. 51 is all about pride and point-making. Good. In the drivetrain duopoly, the real winner here is you, the consumer.

Speaking of pride, kudos to Shimano for swallowing its and coming out with a new freehub design. Sayonara to the previous freehub design, which dates back to around 1992, and the move to eight-speed from seven-speed (who remembers the hoo-ha that created?). The new Microspline freehub looks to be extremely well thought through and will probably remain unchanged for another 27 years or so.

IceTech pads rattle distractingly

Going back to the shifter. Shifters can’t really get any better than this, can they? Multiple shifts with either finger/thumb. Grippy rubber pads add to the responsive feel in a way that ridges, etching or griptape can’t compete with. The shifting noise is also worth highlighting here. No-one ‘schnicks’ like Shimano. Even during rowdy riding, you can hear, as well as feel, the exact split second that shifting has occurred. Although all of this is felt at the shifter, with your fingertips, credit must also be given to the rear mech. It’s a stiff old beast with nary a hint of delay, flex or give in its operation.

Do I have anything negative to say about new Shimano XT? Yes, two things.

Firstly, it’s just not very pretty is it? There’s nothing that really aesthetically lifts this groupset above SLX or even, dare I say, Deore M6000. The shifter is lovely looking in its own way, but who looks at shifters? The cranks and the rear mech are terribly drab. Borderline ugly. The saving grace visually are the brake levers and the disc rotors.

Which brings us to my secondary negative. The rear brake’s inconsistent bite point. This is a thing that has plagued XT brakes for a while now. The rear brake had a wandery bite point from the get-go. I did think I’d cured this with a pre-ride bleed, but literally on the last ride before commencing this review, the wandering bite point returned. It may not be as bad as previous XT brakes – that could alarmingly pull to the bar upon first grab – but it’s still not great and it causes you to frequently pre-brake to check it is working whilst riding – which is something I’d rather not have on my mind. If it was only the front brake I was reviewing, 10/10 (or near as dammit). Yes, the finned IceTech pads do rattle a bit but I can live with it until they wear out and be replaced with non-finned pads (Alpine riders may wish to keep finned pads and silence them with a bit of canny Gorilla Tape-ing).

Have I forgotten anything? Oh yes, the crankset. The fact that I nearly forgot to mention it is testament to its greatness. Shimano’s two-bolt crank arrangement is the best mountain bike crank/BB system out there. No ridiculous amount of tightening Nm required. It doesn’t drift loose over time. It’s the most creak-free design going. It’s just a headset and steerer turned on its side. Long may it never change. The only change, despite the first glance looking like a spider-arm layout, is the move to a cinch chainring mounting design. Once again though, it is a really, really boring crankset to look at.

Overall then, Shimano’s new XT is a tale of winning gears and frustrating brakes. Over to you SRAM.


Rear derailleur:284g / £99.99
Shifter:120g / £54.99
Cassette:470g / £139
Chain:252g / £39.99
Crankset:620g / £199.98