By Vernon Felton
Shimano's premier mountain group, XTR, receives a facelift every four years or so. For 2011, XTR gets its fifth makeover. The results are impressive. Yes, the group now has 10 speeds in back, but that's just the tip of the iceberg. Every component has undergone a significant metamorphosis.
The bottom line?
The new XTR boasts a more efficient and stable drivetrain.
Disc brake performance (already good) is definitely better.
And there are now unique XTR components tailored specifically to two different types of riders: (1) cross-country racer types and (2) trail riders looking to tackle more technical terrain. We spent a few days doing the latter--flogging a set of the new shiny parts on the punishing trails around Downieville, California.
This is what we learned--the broad brushstrokes version. Look for a long-term test of the new XTR in an upcoming issue of BIKE.
Two Flavors of XTR
During the height of the`90s mountain-biking boom, a whole lot of companies made a whole lot of money selling ultra-light, ultra-bling components. If you could CNC the bejeezus out of a hunk of aluminum and anodize it baby blue, you practically had a license to print hundred dollar bills.
Shimano responded by creating XTR: a component group that utterly lacked a teal color option, yet worked flawlessly and single handedly destroyed the market for fly-weight, CNC'd, anodized widgets.
Anyone and everyone who wanted the best parts rode XTR.
Simple as that.
The mountain biking market, however, has changed a hell of a lot since the advent of XTR. A one-size-fits-all approach to gear doesn't cut it anymore and this has posed a challenge for Shimano. Should XTR be a cross-country racer kit or should it be a more bash-proof, ultra-light everyman's group? Each generation of XTR has shifted to one direction or the other.
This time around, Shimano has taken a different tack: creating a core group of XTR components (chain, shifters, derailleurs) and adding wheelsets, pedals, brakes and (to a lesser extent) cranks in two different flavors: XC Race and Trail.
You want to slap on a set of skinny tires and race short-track? There's an XTR for that. You're more interested in cleaning über-technical trails on a lightweight trail bike? There's an XTR for that too.
Not Simply an Extra Gear
Another gear? Is that really a good idea? As someone who rides muddy trails nine months of the year and, thus, still hordes eight-speed XTR components, I wasn't initially bowled over by the idea. A few days on the new stuff, however, made me realize that what we're looking at here isn't simply an exercise in making a skinnier chain and squeezing another cog on the cassette.
Improving efficiency and durability were the prime motivators behind the new XTR drivetrain. This, most noticeably, boils down to pairing a wider-range cassette (now with a 36-tooth granny) to cranksets that feature more compact chainrings, with less of a jump in size from one ring to the next.
There's a raft of benefits that accompany this change. Here are just a few.
Front derailleur shifting is improved (a bit quicker) thanks to the smaller gaps in chainring size. Chain tension is also reduced (by up to 30 percent, according to Shimano, in the large and middle ring). Less tension reduces friction and drivetrain wear and tear. Theoretically, the new 10-speed chain should last longer than its predecessor. You also spend less time in the granny gear and, as a result, more time in the middle ring. Since most full-suspension bikes are designed to pedal most efficiently in the middle ring, you should also experience less suspension bobbing as you scale climbs in your middle ring instead of the granny. This was definitely true on my Santa Cruz Blur LTc.
A Sexy Chain?
While chains are undoubtedly the least exciting component on earth, the new 10-speed chain was a crucial component in this XTR re-design. The chain is the make or break component in this group--if it fails, you're not going to spend the afternoon admiring the shiny finish on your new XTR parts because you'll be pushing your bike home. Ride over.
The new XTR chain takes cues from the 10-speed Dura Ace model. It's an asymmetric model featuring task-specific plates. The outside plates are optimized for front shifts. The inner plates are optimized rear shifts. Another important point: you have to mount this chain correctly or suffer the consequences: namely, shitty shifting. Apparently, the reps at Shimano are traveling the country and backwards chains abound. Mount your 10-speed chains so that the XTR logo is visible on the drivetrain side of your bike. It's a small thing, but it makes a difference.
As with Dura Ace, the XTR chain shaves grams via hollow pins. This is not, however, a Dura Ace chain with a different logo on it: it's been designed to withstand the higher load stresses that go hand in hand with mountain biking. It's also designed to shed mud more effectively than previous chains.
It's conceivable that the 10-speed chain may prove more durable--even in muddy conditions. That's certainly the party line at Shimano and it makes theoretical sense. After all, a chain that sees less stress and collects less mud should last longer. We'll see how it pans out after a winter in the Pacific Northwest.
Finally, the new XTR chain does not come with a master link. That means you'll need to use Shimano's universal 10-speed connector pin should you bust the chain or you simply have OCD and suffer from the irrational fear that kittens will die if you fail to remove the chain when overhauling your bike.
Light, yet positive, shifting
Shimano tweaked both the shifters and rear derailleur to improve the feel at the shifter and the overall stability of the system. If you look at the new rear derailleur, you'll see that it's arm length is longer than before. Increasing the arm length gives the shifters greater mechanical advantage over the derailleur spring; this reduces cable tension, which makes the system less finicky to adjust. It also creates a more constant or "linear" feel at the shifter paddles. In short, you don't feel a ramp up in pressure as you shift up the cassette to the bigger cogs. Shimano, however, also took a note out of the SRAM notebook by creating more positive detents. Out on the trail, this results in shifts that are nice and light, and yet accompanied by a more positive "click". It's a definite improvement.
"Stability" was a design goal for the new XTR. Or to put it another way, there's not much point in jumping to 10 speeds if doing so results in countless ghost shifts and constant fiddling with barrel adjusters. Shimano promises that the new shifting setup will be less sensitive to contamination, variations in cable housing stiffness and, last but not least, funky cable routing, which abounds on today's full-suspension bikes.
One last cool feature? You can use the same shifters for both the triple and double cranksets--simply twist the 2X/3X mode converter on the front shifter. Nice.
Five Crankset Options
There are five XTR crankset options. The bread and butter model, which will make the most sense for most riders, is a close-step, triple-ring crankset that sports a 42-32-24 chainring combination. For comparison's sake, today's standard nine-speed ring configuration is 44-32-22.
Since the 32-tooth middle ring is the de facto driving gear under the new 10-speed set up, Shimano beefed up the ring's durability by mating titanium teeth paired to a stiff, light composite ring. For the super-fit types or the folks who simply feel compelled to rock the racer-ish, 2X10 get-up there are also three close-step, double-ring crankset models (40/28, 42/30 and 44/32).
Living, as I do, in a land of big rocks and downed trees, I routinely destroy chainrings and, thus, was pleased to find that you can remove the big ring on the triple and bolt on a bashring. Likewise, if you want to go the double and a bash route, there's a 38/26-tooth double crankset that will accept a bashring.
Brakes: More Power, Less Fade
The most noticeable tweaks to XTR come packaged in the new disc brakes, which now sport a barrel-shaped master cylinder and a hinged bar-clamp that will make cockpit adjustments a whole lot easier. There are, however, plenty of less obvious changes afoot.
Excess heat is the hobgoblin of hydraulic disc brakes; it can lead to warped rotors, decreased pad life and brake fade (that mushy, Where the f— did my brakes go?!? sensation). The new XTR disc brakes were re-designed, with a particular emphasis on reducing heat in the system. To accomplish that goal, XTR boasts a stainless steel rotor with an aluminum core, which Shimano claims reduces rotor heat by 100 degrees (Celsius). That reduction in heat should not only reduce brake fade, but also reduce wear and tear on the brake pads (Shimano claims that it doubles the life of the brake pads in dry conditions). The other half of the cooling technology comes in the form of Shimano's new Ice Tech brake pads, which sport aluminum radiator fins, capable, Shimano contends, of dropping rotor temperature another 50 degrees (Celsius).
In addition to running cooler, the new XTR brakes are lighter and more powerful than their predecessor. The brake comes in two trims: XC Race and Trail. The Race version boasts a ten percent increase in stopping power and the Trail a 25 percent boost (which makes them even more powerful than the current crop of XT brakes).
While Shimano is adamant that XTR is not intended to be a set of stoppers for the Gravity-racing set, the new brake does come with a stunningly wide range of rotor size options--from 140 to 203-millimeters. In short, you'll be able to squeeze a hell of a lot of stopping power out of a brake that weighs just 809 grams (that's the combined front and rear system, including rotors, weight for the heavier Trail version).
The post-mount caliper is the same on both XTR brakes--the main difference is in the levers: the Trail model sports a Servo Wave brake lever, which provides greater leverage at the end of the lever stroke, thus enabling you to wring more power from the brake without death gripping them. The lever is also slightly wider on the Trail version and sports both reach-adjust and lever-stroke adjusters. The Trail brake comes stock with metal pads. The Race version will come with resin pads.
I rode the Trail version of the brake with (in an odd twist) resin pads installed. Modulation was excellent and brake squeal was minimal--things that you'd expect out of a resin pad. What surprised me, though, was the complete absence of brake fade. Was all that Ice Tech coming into play? It's hard to say. Our first day's ride included a 5,000-plus foot descent...it's the kind of downhill that can make disc brake systems get all mushy. Then again, we did stop to regroup from time to time, so that may have helped keep the brakes cool all on its own.
I will say this, for a lightweight brake, the power is excellent and modulation, always a strong point for XTR, is still right up there with the best. I'm looking forward to getting a set of metal pads--I'm curious to see how well they telegraph the locking up point and, besides, the rains will soon return to Bellingham and resin pads rarely last in those conditions.
Trail and Race Hoops
Shimano also took the two-headed XTR approach with their new hoops. To wit, the Race version weighs just 1,480 grams (about 50 grams less than the current hoops). The Trail version is burlier: it features a wider (21-mm internal width) rim, thicker (14-guage) spokes and a 15-millimeter thru-axle front hub. It is also available with a 142X12-thru axle rear hub. The extra burl adds a few extra grams. The Trail version weighs in at 1,670 grams, to be precise. Both wheelsets use cup and cone bearings, Center Lock rotor mounts and lightweight, Scandium rims.
The Trail version's wider rim helps spread out the footprint on the larger-volume tires you'll want to run for more aggressive and technical terrain. Our test wheels were shod with tubeless-ready, 2.4-inch WTB MutanoRaptors. I ran my tires at 28 PSI and hit countless scary-big rocks with nary a complaint from the wheels. So far, so good.Pedals: A Better Platform
Last, but not least, Shimano updated the pedals with an eye towards reducing their platform height (less rock smashing), yet increasing the platform area. The pedals come in both Race and Trail flavor, the latter sports an aluminum cage...sorta like a super-pared down 636. I rode both the Race and Trail models, and the increase in surface area is noticeable: there's much less of a rocking sensation at the cleat.
A few days of riding is, by no means, enough time to form definitive opinions about a product. Still, I've destroyed wheels, tires and derailleurs on single runs at Downieville and I didn't witness one malfunction on any of the 16 journalists' bikes during two days of riding trails that epitomize rocky, Sierra riding. That's impressive: doubly so when you consider how light this stuff is. 2011 XTR (the XC Race version) will weigh nearly 300 grams less than the current version. The Trail version actually gains about 158 grams, but is also a much burlier set of components than anything that's ever worn an XTR logo.
Shifting is excellent. I bent four teeth sideways on my big ring after a couple hours worth of rock-skiing during our second day's ride. Despite that fact, shifts were absolutely butter smooth between the big and middle rings. I also spent 80 percent of my time in the middle ring--I normally saw away on the Granny ring a whole lot more. I had my doubts going in on this one, but after giving it a go, I can see the logic behind the Dyna Sys setup. I was able to get the rear derailleur to chatter about once or twice, but in both occasions I was pedaling like an eejit through long stretches of baby heads. In other words, I'd be amazed if that hadn't happened.
Long story short, Shimano has made big strides with the new XTR. Once we've spent a good six months aboard it, we’ll let you know how it stands the test of time.