“Seriously?”
That was my now-reconsidered response to news that Shimano had invented electronic shifting, back in the aughts when the original Dura-Ace Di2 group was introduced. It seemed to me, at the time, an unnecessary extravagance. My initial resistance I can blame on them. At that point in time, Dura-Ace was the best-shifting group on the planet (sorry, Campagnolo, but that’s a fact), and in my limited ability to imagine improvements in bicycle componentry, I didn’t see how you’d significantly improve on “best.”
Then I rode the group. And then I shut the hell up. Yet again. I write “yet again,” because Shimano has introduced a number of products over the years to which I thumbed my nose. And in every instance (we’re talking 100 percent), I’ve chowed down on my statements. You’d think at some point I would learn.
I did, in fact. When Shimano introduced Di2 for mountain bikes with the M9050 XTR group I had the good sense to appreciate that flawless, lightning-fast shifting would bring an appreciable improvement to a mountain biker’s experience. That product intro was more than 10 years ago, and Shimano’s M8200 group represents a notable evolution of the Di2 saga.
Look ma, no wires
Let’s begin with the basics: This is the first Deore XT group to offer electronic shifting. It improves on the M9050 XTR Di2 group from 2014 with the addition of one more cog (from 11 to 12) and the elimination of any wires and a battery that remains wed to the bike in most circumstances. The battery is now housed in the rear derailleur—a derailleur the size of a large chicken breast—and it is removable for charging, which also means battery swaps on rides should you kill the battery mid-ride (more on this in the section titled, “Misadventures”). The shifter is also far more ergonomic and allows for paddle position and angle adjustments.
Shimano says that battery life should give a rider 30-49 hours of riding, or 1,000-2,000km (600-1200 mi.) of riding. Due to some poor record keeping on my part (forgetting to record a few rides), I can’t say exactly how many hours of riding I got before I depleted the battery, but I estimate it was north of 40 hours. For reasons I don’t understand, Shimano doesn’t give battery life in the single most objective measure possible: number of shifts. This would be helpful because many of my rides can be characterized by a long climb with few shifts followed by a long descent … with few shifts. Were I riding this group in a place with consistently rolling terrain, I’d be shifting far more often, and I bet battery life would clock closer to 30 hours.
The slowest this group ever shifted occurred when I’d just replaced the rear wheel and I was pedaling from a dead stop in a big gear and with an impossibly low cadence, it took several pedal strokes before the chain downshifted. At anything resembling a normal cadence, downshifts occurred at a speed that did make an appreciable difference for offroad riding. And that may be the core truth about Di2: The benefits electronic shifting offers riders make the greatest difference for offroad riding.
28×51
I chose the long-cage rear derailleur paired with the 10-51t cassette. Shimano also offers a short-cage version that matches with a 9-45t cassette. Were I living in a place that was flatter or where the climbs were gentler, I’d go for the short cage derailleur and the cassette with the narrower range, but because I can do rides that average 200 feet of climbing per mile, I went for the big cassette and a 28-tooth chainring. They offer the chainring in 30, 32, 34 and 36t sizes. I’m grateful that they make the 28t ring and I’ve yet to use the 10t cog except when going downhill on the road.
Look ma, no scrapes
For anyone who rode the M8100 Deore XT group, it is unlikely you’ll notice a difference between the old and new brakes beyond the cosmetic differences. The selling point Shimano leans on is greater thermal stability, meaning the bite point—the point in the lever throw at which the pads contact the rotor—doesn’t drift depending on how hot (or cold) the brake fluid gets. Now, a drifting bite point has been my consistent complaint about XTR brakes, but I’ve experinced bite point drift exactly once with Deore XT brakes. It was on a long descent during which I didn’t stop, so I didn’t see this as an issue that needed solving, but I don’t live in the Rockies, so maybe I should sit down.
To achieve greater thermal stability, Shimano chose a new mineral oil for the brakes, crafted pistons from resin, rather than ceramic, and implemented new seals. Some people also complained of rattling in their brakes and they made an adjustment to the pads to prevent that. Shimano changed the lever geometry to make the lever movement more ergonomic while also increasing leverage. What I notice is that the levers lack the flex I find (and dislike) in XTR.
I’m riding the four-piston brake, a brake that when I first encountered it in the form of the Saint brake, I didn’t appreciate the power they offered. I was accustomed to braking more gradually, modulating more and Saint was designed to reward late, hard braking, and it took me a full season to learn to trust my tires (and handling) for not braking until the need was dire.
Power on
Shimano was slow to begin offering 29-in. wheels, but the Deore XT wheels have, in my experience, set a new standard in reliability and ease of setup. They come with valves installed and need no tape. Better yet, considering all the times I’ve managed to ping a rim on a rock, they rims have remained dent-free and the wheels truer than I’d have thought possible.
When I’m riding on my local trails in Northern California, rock gardens are plentiful as Starbucks. In Washington, I’m more likely to strike a pedal on tree roots. Stuttered pedal strokes to avoid rock strikes and roots are as fundamental a part of my skill set as picking up my front wheel. This latest edition of XT wheels have reduced freehub engagement from 6.7 degrees to just 3.5 degrees. The difference is appreciable and meaningful.
Shimano has traded traditional cup-and-cone bearings for cartridge bearings with improved seals. What I can say I’ve noticed is slightly quicker rolling in the form of catching up to other riders on descents, a phenomenon I’d only experienced previously with wheels using Industry 9 hubs.
Misadventures
In moving this mountain bike between jurisdictions, I packed the spare batteries and charger with my tools, not my hydration pack. A choice that seemed responsible until a couple of weeks ago when I found myself on the side of Tiger Mountain with my chain stuck in the middle of the cassette. I estimate I had more than 40 hours of riding on the battery by the time I ran it down.
The closest thing to a criticism I have for this group was my realization that on rowdy descents the knuckle of my right thumb would occasionally bump the downshift button. I didn’t realize my knuckle was bumping the button hard enough to execute a shift, but the third time I sat down only to experience the drivetrain to downshift a cog or two as I began pedaling, I realized just what was happening. The solution required the heretofore unknown and arcane move of sliding my right hand 3mm to the right.
Franklins and Jacksons
Retail on the M8200 Di2 group is $2099—depending on brakes and a few other specifics, and a 29-in. wheelset tacks on an additional $570. I’ve got more months on this group, so I can’t yet say how it will hold up long-run, but what I will attest is this: based on the performance of this group so far and my experience of previous Deore XT groups, I continue to believe that this group is worth every penny. Its combination of performance and durability, I’ll take it any day over XTR. That’s a strange statement to make. While it’s true that Ultegra is now so good that the performance differences between it and Dura-Ace don’t really make the extra investment in Dura-Ace worthwhile, Dura-Ace doesn’t sacrifice any aspect of performance to Ultegra. But when I think about what mountain biking is as a sport, Deore XT is better suited to my needs. I want a drivetrain that always shifts, brakes that don’t fuss and levers that don’t flex.
But what of electronic shifting? Do you need it? No. No one needs electronic shifting. However, as I’ve often written, the bike that disappears beneath the rider is the better bike because the bike that calls attention to itself is an impediment to flow. And I will argue that a bike that prevents you from entering flow is a problem that deserves fixing. I hear people deride electronic shifting with the frequency of changing gas prices. It’s easy to compare a bike with electronic shifting to a bike with mechanical shifting (acoustic?) and think, “Well that’s just silly/too expensive/unnecessary/shark jumping.” And for some people, that’s true. But to anyone who has ever valued the performance qualities of a high-end bike, the flawless, instant shifting of Deore XT Di2 makes an appreciable difference.
Final thought: The next time Shimano introduces a fresh idea to cycling, I promise not to balk.