Shimano XTR Di2 Review & First Impressions - Better Than SRAM AXS?

Words & Photos by Jared Erickson

While SRAM has had their version of a wireless drivetrain out in the wild for over 6 years, Shimano has been quietly and patiently developing their own version. Now we have the pleasure of saying Shimano XTR Di2 is finally here. The question remains - is it worth the wait, and how does it compete to AXS and T-Type now that SRAM has been refining and advancing their own tech as well? Read more for our first impressions and review on Shimano's top tier XTR wireless drivetrain, and how it stacks up against the competition.

Overview

Shimano's XTR M9200 Di2 (despite the Di2 nomenclature and association with wired groups in the past) is the brand's first wireless MTB groupset, and has a lot to offer when it comes to features and performance. It's a refreshing take on a wireless groupset and its impressive performance will be sure to please both Shimano and SRAM lovers. Having experience riding mechanical Shimano drivetrains as well as mechanical SRAM plus AXS & T-Type, I was interested and excited to see how this would stack up. Before we get into the riding impressions and how wireless XTR performs, let's go over the specs and check out some of the nitty gritty details on Shimano's new drivetrain offerings.

Specs

RD-M9250 – Wireless Rear Derailleur
- SHIMANO SHADOW ES Technology
- Precise wireless shifting
- Robust structure with skid plate design
- Solid pulley construction
- Removable and rechargeable onboard battery
- Long Cage RD-M9250 SGS for use with 10-51T Cassette
- Mid Cage RD-M9250 GS for use with 9-45T Cassette

RD-M9260 – Rear Derailleur for E-MTB
- SHIMANO SHADOW ES Technology
- Wired rear derailleur for E-MTB
- Constant power supply from e-bike battery
- AUTO SHIFT technology
- FREE SHIFT technology
- Long Cage SGS
- 12-Speed RD-M926012 for HYPERGLIDE+
- 11-Speed RD-M926011L for LINKGLIDE

CS-M9200-12 – Cassette Options
- Smoother, more durable shifting under load
- 12-Speed HYPERGLIDE+
- MICRO SPLINE
- Optimized for lightweight and durability
- Cassette Options: 9-45T and 10-51T

FC-M9220 – Trail/Enduro Crank
- High-durability crankset for Trail/Enduro
- Enduro-specific spindle ensures stiff power
transfer and impact resistance
- Proven HOLLOWTECH II construction
- Standard 176mm Q-Factor
- Crank Arm Length: 160, 165, 170, 175mm
- Chainline: 55mm

FC-M9200 – XC Crank
- Lightweight crankset for XC riding and racing
- Proven HOLLOWTECH II construction
- XC-friendly 168mm Q-Factor
- Crank Arm Length: 165, 170, 175mm
- Chainline: 55mm

First Impressions

For context, I've had this drivetrain on my Yeti SB140 for a little over 100 miles of riding in the span of a week. We'll have a full on long term review in the coming months, but in the meantime I feel as though I've got a good impression of how it performs in the real world. Of course that's not nearly enough time to suss out any sort of durability concerns, so we'll have to trust that Shimano has done their homework in that regard. Seeing as how it's years in the making, I'm confident in trusting them. 

First, let's talk about the shifter/controller, or whatever you'd like to call it. It has an extremely natural ergonomic feel that was very intuitive right out of the gate. For people who felt as though they couldn't really get along with SRAM's version of an electronic drivetrain controller, they will likely get along with Shimano's. The levers are positioned in a way that is very familiar to riders, and the angle of the shifter levers is also adjustable with a 3mm hex key. With some minimal adjustments, I was quite happy with the shifter ergonomics and function. 

One feature that Shimano riders will recognize is the ability of the shifter to double shift with the extra push of the shifter button - you can either press it lightly for a normal shift, hold it for continuous shifting, or a harder push for a double shift - either up or down the cassette. In my experience it has been very intuitive and enjoyable to ride, and the tactile feel of the shifter is extremely satisfying. It has the sort of precise feel that you would expect from Shimano. 

Speaking of shifting, let's talk more about how it performs on the trail. Once you become used to the feel of the shifter (which I was used to after only a couple of rides) you can effortlessly and mindlessly row through the gears. The feel of the trigger has a nice light action that allows you to change gears as easily as it is to think about it. Communication with the derailleur is instantaneous, and the shifting is extremely quick and crisp. As I mentioned before, after riding T-Type for over a year on my Forbidden Druid I was excited to see how this new XTR would stack up.

Initially, I felt as though the XTR wasn't quite at the level of T-Type when it comes to shifting under load and just how smoothly and effortlessly the chain would go up and down the cassette. But then I started pushing it harder and shifting under heavy loads and I became even more impressed with how it performed. In my personal experience so far, the shifting speed feels faster than SRAM's original XX1 AXS, and the smoothness, precision and ability to shift under load is nearly at the level of T-Type, if not at the same level. For a lot of riders, this drivetrain could be the goldilocks group when it comes to effortless, fast, seamless shifting - especially for those who may have felt like T-Type doesn't shift as fast as they like, those who feel like regular AXS doesn't shift as smoothly as they like, or those who want the T-Type level of shifting and either don't want to ditch their derailleur hanger or don't have a UDH. Or, for those who simply want to upgrade their mechanical XTR to the best current version possible.

The use of a derailleur hanger instead of a full mount T-Type style derailleur is sure to have its pros and cons, and some will prefer one or the other and have their own biases as well. On one hand, with XTR Di2 there's no special mounting instructions, it still has b tension & high and low limit screws, it works on all bikes, and it still performs on an incredible level thanks to Hyperglide technology. There's something about using a traditional derailleur hanger that will appeal to a lot of riders. On the other hand, you can't deny the fact that T-Type works incredibly well thanks to it's full mount style and cassette mapping tech. Some riders may feel as though Shimano is behind SRAM in the tech department, and some might feel as though Shimano's more conservative approach is more in line with their actual real world needs on the trail, and has sort of hit the technological sweet spot so to speak.

When it comes to the rest of the hardware, I've been running the 9-45t cassette with the short cage derailleur in conjunction with the 30t chainring and new XTR 165mm cranks. I've found this setup has a great gear range and I've really only been missing a granny gear on the steepest of steep climbs - even then I've been happy with a 45t cog as my easiest gear combined with a 30t up front. For some context, this is on my SB140 that comes in around 29lbs in it's current guise - on a heavier, more enduro focused build, riders will likely opt for the 51t cassette unless you've got some legs. We're getting one of those groups in for test as well and will report back as a part of our long term review on how that performs.

Final Thoughts

Shimano has finally come to the table with their top tier wireless XTR groupset, and in my book, its absolutely worth the wait. The fact that Shimano has stepped up to the plate with incredible modern day drivetrain technology that performs flawlessly is exactly what the MTB world has been waiting for, and those who plop down their hard earned cash for this electronic upgrade will be pleased with the incredibly fast, effortless, smooth shifting that it offers. Now that both of the big "S" drivetrain manufacturers have a modern day wireless groupset, things are about to get very interesting.