13 May 2019

Shimano's top-shelf goodies had a complete makeover drawing a lot of attention from those that like the best type of shiny bits. The new Shimano XTR M9100 group is different at each turn and makes a strong move in the highly competitive SRAM vs Shimano match.

The not-so-minor details

Product

Shimano XTR M9100

We lusted over Shimano XTR long before SRAM became a thing, but they certainly don’t have the clear run anymore, it’s now harder than ever to pick the ultimate top-end groupset with sensational options from both camps.

Shimano has a knack for impressing us with the quality and performance of parts and beautiful workmanship, while simultaneously baffling us with their unique approach to problem-solving and their somewhat dry personality. The finishes are all-class, the brake heat management is impressive, and with greater range, the whole package doesn’t hold back

Here are a few thoughts on how we are getting on with the flashy stuff from Japan so far.

Chain noises be gone!

After subjecting our  Shimano XTR M9100 equipped Giant Trance 29er to all sorts of conditions, we’re happy to report that the chain and everything it touches remains quiet and smooth. Previously the XTR and XT drivetrains would get a bit ‘grindy and groany’ out the other side of a creek crossing, or during rides where the trails are wet.

This stuff is amazingly quiet, with the chain sitting on the chainring teeth securely without hesitation, even with a good coat of mud and water. Out of the saddle, it doesn’t do anything different, just smooth and silent running.

Smoother and quieter than ever, in the dust, mud and everything in between.
The interface between chain and ring, cog and wheel, it’s very secure smooth and quiet.

Brake pad rattle returns, c’mon, seriously?

Like the four-piston XT brakes we’ve tried many times on multiple test bikes, the new XTR four-piston brakes with the finned Ice-Tech pads began to rattle when riding over chattery terrain, to great dismay.

Noooooo, the pads in the new XTR four-piston brakes rattle when the bike bounces around.

It’s not the end of the world; the simple fix is to remove the pads, grab the little steel x-shape spring and carefully spread them apart a touch further to strengthen their spring force, holding the pads against the pistons with greater strength. Easy for the consumer to fix, but wouldn’t it also be easy for Shimano to sort it in the first place? Anyhow, we’re picky.

Brake lever action so smooth, with a different taste of bite.

The new levers feel delightfully smooth to pull on, with no clicking or tactile feedback like we would often find in the previous models. The Servo-Wave mechanism (under the lever you can see a little roller-cam increasing and decreasing the rate of lever pushing the piston) is smoother than before.

We love the previous model XTR brakes, warts and all, but they certainly had varying consistency in lever feel with one pair on long term test clicking in the Servo Wave mechanism when squeezed.

In terms of power, the four-pot brakes exhibit a very different power and modulation style. In comparison to the previous XTR brakes, there seems less bite the moment the pads touch the rotor, but the power that comes on when you continue to apply the lever is strong, and at the bottom of a long run, the fatigue in the hands is hardly noticeable.

We’re yet to take these brakes to enormous snow-capped mountain descents, but so far they seem to have addressed our minor gripes with the clicking levers and overpowering bite, and also improved their modulation feel.

New tools, new freehub. Early days for new processes.

To achieve the new 10-51 tooth gear range, Shimano needed to develop a freehub body with a smaller diameter. The new Micro Spline body can take a tiny ten tooth sprocket – like SRAM’s 12 speed Eagle – but now we are posed with the introduction of a new standard – just like SRAM with the XD Driver – and it’ll take some time for wheel manufacturers to catch up. So far, it’s a Shimano and DT-Swiss affair, who’s next?

Chain quick-link, finally.

Shimano’s reluctance to adopt the quick-link in favour of the single-use pin was quite frustrating. In late 2017, Shimano finally announced an 11-speed quick link, while it’s not intended to be a reusable and still not found on all Shimano equipped bikes it’s a small feature with a significant impact. It makes trail-side repairs a whole lot easier.

Pop a spare link in your kit, or tape it to your cables like the enduro pros, and you’re covered. This XTR groupset is the first proper experience with a Shimano quick-link; we hope to see them become more commonplace.

The shift is crispier than a bag of frozen snow peas and smoother than butter.

Seriously, the shifting is out of this world. After a couple rides to let the drivetrain bed-in, the shifting performance has impressed us, and we think Shimano has made some serious improvements to previous incarnations here. Laying down the power and shifting gears in either direction, the result is a quick and precise change, practically seamless and so smooth.

Impressive action! Needs to be ridden to be fully appreciated.

We are looking forward to seeing how the shifting handles wear and tear, and a full winter of riding. But so far we are more than impressed.

Stable pedals, but what’s with that little migrating seal?

It’d be hard to improve on the previous XTR pedals; our only gripe was the tendency to loosen in the axle bearings, the new M9100 pedals are said to address that. The new shape offers increased support for the shoe while remaining slim for ground clearance.

But, since very early on a rubber o-ring seal would creep out of the pedal body and along the axle. We’d push it back into place, and it’d eventually make its way out again. Surely the seal is there to protect the internals, but it won’t do its job if it’s not in its intended position.

We spotted it occurring on several bikes at a recent press camp, and at the EWS in Tasmania, so we’re not the only ones. We’ll see

Note the seal on the axle, it is meant to sit inside the pedal body slightly but keeps popping out.
The pedals are large, yet slim.

Range a-plenty, 10-51 just a little more than 10-50…

We can’t help but think Shimano gave SRAM the middle finger by one-upping the range offered by the Eagle drivetrain, by just one more tooth. 10-51 is more than Eagle, just, but we would have been happy with 10-50 anyhow. The extensive range is gold, in all situations.

10-51, too good.

Tidy little dropper lever, and i-Spec EV adjustability galore.

A new part for Shimano is a dropper lever, mounted directly to the brake lever the smart little lever is a small but very impressive piece of the puzzle. It mirrors the shifter on the right-hand side, sitting just a little closer to the grip. The i-Spec (Shimano’s brake/shifter management mount) has a large amount of range, allowing you to roll the shifter and dropper lever up and down, and also slide in and out. Just watch the grip length…

Short grips are best.

While the i-Spec system is excellent, we did run into an issue with the grips fitted to the Giant Trance 29er being too long, that we couldn’t slide the brake lever out far enough, the new brake lever arrangement has a brace in addition to the clamp, to stiffen the brake lever when you squeeze it. Makes sense, but watch out for long grips getting in the way of possible positions.

Note the lever’s body now contacts the handlebar with a new brace, right up against the grip in this photo. Long grips may get in the way of the desired lever position.
The Trance 29er is a great platform to test the new XTR.

Stay tuned for more as we continue to observe and analyse the new generation Shimano XTR, but so far, so good.

Want more details about the new XTR? Jump here, where we answer 11 questions on the new groupset. 11 questions, 12 speeds.

More on the lovely Giant Trance we fitted XTR to here: Trance 29er introduction.