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SRAM X0 2x10 Review
The SRAM 2X10 system is a couple of years old now, and what was once an oddity has become commonplace. The 2x10 system has some great virtues, such as reduced cross chaining, quicker and smoother front shifting, decreased overlapping gear ratios, weight savings and a narrower Q-Factor. In simpler terms, you get maximum functionality and minimum complexity, with faster shifting, more efficiency and lighter weight across a full range of gears. I will use their marketing term, since it sums it up best: 2X10 doesn’t mean more gears, it means the right gear.
SRAM's 2x10 X0 gets the trickled down technology from their flagship XX group, which was the first mountain bike oriented 2x10 on the market, but the X0 comes with a better price point and only a slight increase in weight, and greater durability and toughness.
Note: Per the immortal Sheldon Brown, it's derailer not dérailleur.
And you know what they call a Quarter Pounder with Cheese in Paris? They call it a Royale with cheese.
SRAM X0 2x10
The trick Truvativ X0 crank arms are made from carbon fiber with a hollow foam core construction, and utilize a separate bolt-on spider for the chainrings, which use their fast X-Glide shifting technology. It comes in a variety of gear options, including 22-36, 24-38, 26-39 and 28-42, which then mates to the 11-36 cassette. The X0 front derailer has a narrower design to match up with the 2x10 system, while the X0 rear derailer accepts the large 36-tooth cog and retains their quick 1:1 actuation ratio. The X0 shifters are available as the ultra sweet Grip Shift or the normal trigger shifters.
I have been using the SRAM X0 drivetrain system since Sea Otter, and I have put it through its paces, tossing it in every type of terrain and environmental conditions, just this side of prodigious quantities of mud. I predominately used the Grip Shift for shifting purposes, with a short foray with the trigger shifters. I ended up testing a 175mm 2x10 crank with 24-38-bash setup, and a cassette with 11-36. The whole group included the following:
Testing was performed on my medium Ibis Mojo HD with the Cane Creek Double Barrel Air rear shock, and multiple forks, including the Magura TS8 and FOX VAN 160. I am 5'9", weigh in at 155 lbs and have been riding since the inception of the RockShox RS-1, and started out on a Bridgestone MB-2 for my first MTB steed. I have mostly ridden in the West, including vast portions of the Colorado Front Range, Sedona, Moab, Fruita/GJ and many parts of the Colorado mountains. The testing terrain is predominantly loose rocky conditions, with many long steep climbs and descents, rock gardens, slick rock, an occasional smooth singletrack and lots of ugly loose gravel. I tend to enjoy gnarly technical terrain, where precise steering and maneuvering are prerequisites, and intricate follow through and large huevos are required.
The local conditions are usually dry, with lots of gravel, sand and fine dirt, which gets into everything, and tends to wreck havoc upon seals, bearings, chains, cassettes, chainrings, and I'm not always the best for remembering to lube the chain, so it tends to get dried out like leather.
Let's go through each portion of the drivetrain and see what's up.
X0 Front Derailer
The 2x10 X0 front derailer is available in four mounting options, High Clamp, Low Clamp, High Direct Mount (tested) and Low Direct Mount, and retails for $74. It can be used in a wide range of 2x10 gearing with a maximum of a 15-tooth differential between the smaller and larger rings. It was specifically designed for 2x10, so the cage is shorter and narrower than a 3x system. The widely spaced pivots of the aluminum links offer stiffness, while the steel cage gives durability and is shaped to work in synergy with their X-Glide front shifting technology.
The X0 front worked nicely, and rolled up and down smoothly, without any stickiness, slop or clunking. There has been a great deal of improvements in the SRAM front over time, and they feel on par with Shimano's counterpart. Using Grip Shift made the front shifting short, quick and lightning fast, in contrast to the long throw on the triggers. I didn't have any cable stretch issues, and what little there was seemed to be within the tolerances, and I have only done minimal trimming. Setting the height of the high direct mount version I used was pretty simple once I had the retrofit direct mount clamp in the proper location on my Mojo HD. Further set up was straight forward, and all I needed to do was some minor high and low screw adjustments, and since it's a 2x system, it is easier to get everything lined up. I noticed that the chain didn't seem to scrape up the plates on the front as much as I am used to, though I am not sure if the metal has better plating or the new design makes the gear change smoother and more precise, which might cause less wear and tear.
The front has done its job admirably with great durability, and the parallelogram has retained smooth operation through its arc, without any issues during the test period.
X0 Rear Derailer
The X0 rear derailer is available in three cage lengths, short, medium and long (tested), and comes in Silver, and Black, Blue, Red and Gold graphic colors, and retails for $255. It can be used in a wide range of 10-speed gearing, with a maximum of a 36-tooth cassette capacity. The inner pulley cage is made from aluminum while the outer is a carbon fiber composite, and the parallelogram linkages are forged aluminum with wide pivots to ensure linkage stability and stiffness. It has sealed bearing pulleys, and utilizes their Exact Actuation Ratio technology, which is a 1:1 actuation ratio (shifter cable travel : derailer movement). The EA offers simple, stable and easy shifting, regardless of the load applied, the cog set spacing and cable tension. Cable routing into the derailer uses their Direct Route Technology, in which it connects directly to the actuation mechanism, to lessen damage, and decrease friction and input effort.
I have always liked the 1:1 actuation ratio of SRAM's rear derailers, and the X0 rear offered crisp shifts that had a nice detent, without any ghost movements or over shifting of the olden days. Rolling up or down the cassette worked just fine, and with the aid of the Grip Shift, you could do multiple swaths of gears at once. Like always, it would be nice to have a barrel adjuster at the rear instead of only at the shifter, but that is a nitpick with the design. Obviously, with the longer cable going back to the rear, I have had to make occasional adjustments, but even with the slop, the miss-shifts were very subtle. With the big 11-36 range of 10 speeds on the cassette, it took a bit of tweaking of the high and low limit screws to get all the gears rolling properly. I did have some issues with getting the low set, while up high the chain never rolled off the cassette on me. The rear has been pretty durable, and has taken a lot of abuse, slamming and scrapping past rock squeezes and ledges, and the only thing it has suffered is some cosmetic alterations along the outside edge. I can't recall doing any of my typical maintenance methods of dropping some oil on the pivot points for better movement and actuation, but it has remained smooth and still works fine. The spring tension has stayed taut, so shifting has been crisp, and the cage pulleys have continued to roll smoothly.
Even under load I never felt the rear give me any issues, regardless of how hard I torqued the system, and it has remained pleasantly quiet. The rear has performed pretty darn flawlessly, and even though it gave the typical reassuring SRAM clunk, it always did what was asked of it, even when the chain wasn't well lubed.
Truvativ X0 Cranks
The Truvativ X0 cranks are available in 2X10 version with 22-36, 24-38 (tested), 26-39 and 28-42 gearing options, along with 3x10 with 22-33-44, and PF30, BB30, GXP and GXP PF bottom bracket configurations. They come in Silver, and Black, Blue, Red and Gold graphic colors, 170 and 175 lengths, and retail from $444 - $513. The three-piece Truvativ X0 cranks are comprised of the drive side arm with attached spindle, non drive side arm and bolt-on chainring spider. The crank arms are hollow carbon fiber composite with a non-structural foam core and aluminum inserts at the bottom bracket and pedal which are co-molded in place. The forged aluminum spider meshes onto a spline on the inside on the non-drive side arm, and in this tested version, it is comprised of a 24 tooth chainring, 38 chainring and a bashguard. The chainrings are made from CNC 7075 aluminum, and the bashguard is carbon fiber. With this 24-38 gearing and the optional 22-36 version, the odd spacing is 104/64 BCD, which is required to fit everything within the confines of the system.
The Truvativ X0 cranks have a minute amount of flex if you stand on the arms during a technical move, and it feels like the spindle twists and/or connections with the spline are where the slight twitch exists, and not the arms directly, but I never felt any loss of power when cranking away while pedaling. The arms are stiff, and have been durable, with only the typical cosmetic shoe rub on the outside. The pedal inserts haven't loosened, which can be a culprit on carbon fiber and aluminum glue-in interfaces. The ends of the carbon arms can get chipped slightly if you hit lots of rocks (like I do), so I added some crank arm boot protectors (courtesy of Race Face). I wish more manufacturers included some sort of end cap protectors, which not only increase the longevity of any crank arm, but the lessen the impact that is transmitted into the bike from hitting things.
Installation was simple, and the bottom bracket spun on without any issues, and the drive side crank slipped easily in and seated with a slight tap of a rubber mallet. When cranking down the non drive side with a 8mm hex, I had to keep tightening the bolt even after the torque wrench reached the spec limit, but it had to be done to seat and snug the arm against the BB spacers, else you could feel the cranks being sloppy along the axis.
The 24-38 chainrings nicely meshed with the 11-36 cassette, especially if your riding style is slow spinning or one with high cadence. The ratio is ideally suited for 29er's, but will also appeal to granny gear aficionados (I am of that persuasion). Their X-Glide technology functions well, and the synergy of aligning the chainring pick-up rivets to the chain pivot pin gives smoother shifts on any terrain or power mode. One of the big keys to the X-Glide is the closely spaced engagement zones around the circumstance of the rings, which gives faster up and down shifts under any load. Although it was effective and quick, I found it somewhat clunky during the transitions, and not as smooth as Shimano. SRAM has greatly improved their ramping on the bigger rings, so the chain usually popped up from the 24 to the 38 without any issues, though on occasion, it could be temperamental. I personally think that a 24-36 would work better, as the difference is closer and wouldn't cause any rollup problems from small to big. The issue is rarer when the chain is in the lower to middle portion of the cassette, or when the chain and rings are all new. They do have other options for other gearing ratios, including 26-39 and 28-42, and the already mentioned micro gearing of 22-36 and 24-38.
The 38x11 (chainring/cassette) gearing isn't the most functional when you want to press the bike to Mach 1, but it will get you going at a decent clip, and this set up is meant for AM and AT riding, not full on XC racing. The 38 offers good clearance and helps to roll over logs and technical rocky terrain (ledges, rock gardens, steps, etc.), and the 24 granny works well for 650B and 29er, or for any of us (myself included) who like to spin at high cadence.
After about eight months the 24 tooth granny gear is starting to feel worn out, and shifts aren't quite as crystal clear like they were when new. Inherently, small granny chainrings get an extreme amount of torque placed on themselves, so it exasperates the wearing, and I notoriously wreck havoc on things with my technical riding and stomping on the pedals. Unfortunately, they don't yet sell individual chainrings, so you'll need to buy the entire spider to replace anything, which costs around $140 each. Of course, it is usually good policy to replace all the chainrings and chain when things get real worn, and maybe even the cassette, but I think the latter is overkill. The 38 ring has stayed in pretty decent shape, and I haven't noticed any real issues with its performance. Once the crank arm was off the bike, removing the spider was a simple operation, and only required unscrewing three small Torx bolts.
The chainrings have done a decent job, and their X-Glide system works nicely, though perhaps a bit clunky. The spider arrangement is quite handy, and will make replacement of everything simple. Even though $140 seems like a chunk of change, you do get two fresh chainrings and a bashguard in one complete package.
The bashguard has gotten some heavy abuse, and is showing some fraying and shredding of the carbon fiber material. It is only happening at two locations for me, right smack opposite the spindle when the crank arms are parallel to the ground. I can't really say if it's premature wear (seems so), but I think a more robust thickness might help with the longevity? At least, it has prevented damage to the large chainring, since without the protection, the teeth would have been pretty abused. I have tossed the bashguard into some ferocious places, and haven't been very kind to it, so the wear that I create might be somewhat extreme.
Truvativ offers their bottom brackets in several versions, including the standard GXP (tested), and the PF30, BB30 and GXP PF. They now include Truvativ's new Gutter sealing system, which has a better seal design, with less drag, greatly improved water resistance and bearing durability. My kit came with the plain old boring Truvativ GXP bottom bracket, but it has been plenty durable and smooth throughout it usage, and I haven't had one issue with it. My local trail conditions have a lot of dust and sand that gets sucked into the vortex of a bottom bracket, and can prematurely end its life from the continual entrance of the fine particulates, along with the occasional rain and snow storms. The stock bearings were adequate for the job, and have remained free spinning.
It's still smoothly rolling, and when I last checked it, I didn't feel any grittiness or stiction, and the cranks easily spun through them.
The XG-1080 is a 11-36 cassette, with gears of 11, 12, 14, 16, 18, 21, 24, 28, 32 and 36, and retails for $280. The XG-1080 cassette's seven biggest cogs are riveted to each other using steel pins, and the largest is made from 7075-T6 aluminum, while the remaining ones are stamped 4130 chromoly steel. The outer aluminum cog and the upper cage are tied into a metal sleeve which transfers the load on the freehub body. The last three cogs are stacked onto the cluster in the typical cassette fashion, and everything gets tied down with an aluminum lock ring. I found that the tight tolerances on the metal sleeve on the cassette didn't leave much room for sliding it on and off freehub bodies, so I lightly sanded the inside to make it fit. That may or may not be an issue on all freehub's?
SRAM has come light-years ahead on the ramps and engineering of their cassettes, and they are now in the same Ball Park as Shimano's, though nothing quite glides like an XTR. The 11-36 cassette worked ideally when combined with the 24x38 cranks, especially if you like a good granny, although you do miss the crankability at high speeds, which a 3x10 or a larger chainring would excel in. I just love the gear ratio offered by the 24x38 chainrings and 11-36 cassette, though it has to be a butt smooth trail to be able to use the 24 front and 36 rear, and I tended to use one or two gears below that when slowly cranking up hills, for better traction and to keep the front end from rising. When using the upper chainring, I really liked the 38x36 ratio, as it could be used on quite a few mild hills, and those with lots of rolling and undulating terrain, and it shined on steep grunt fire roads.
I have been pretty happy with the longevity of the cassette, and it keeps shifting just fine, long after the chainrings have started to give wear issues. The freehub body transferring system, which is comprised of the notches on the large aluminum cog and the metal sleeve, seem to do their job, even though it might be a tight fit on some hubs. The improved ramps on the cassette greatly aid in faster, cleaner and smoother shifting, even when under heavy loads.
PowerChain 1091R Chain
The PowerChain 1091R is made from Nickel silver with Chrome hardened pins and hollow rivets, and retails for $65. It uses the highly functional PowerLock tool-less connecting link, which always makes installing and removing a chain much easier. When the chain was new, it shifted without any issues, even when I forgot to lube it. Like most chains, if poorly lubed it can have some problems in rain and snow storms, especially when there are sand and gravel on the trail, though a quick shot of lube solves the issue. The chain is showing its age after eight months, but it has lasted a good long time for my extreme abuse. I tend to be a low gear granny monster, wrecking havoc and huge amounts of torque on to the entire system, and I have broken my fair share of chains from any manufacturer.
X0 Grip Shift
The X0 Grip Shift is an excellent system, offering smooth, crisp, distinct and solid shifting, without any miss-shifts or dropped gears. The front gives a decisive and short throw that almost feels effortless to move between the chainrings. The rear allows huge swaths of gears to be rolled through on the cassette, or just one at a time, making for precise and easy selections. The synergy of the three rows of thunder ball bearings and the metal shift indexing makes for an excellent tactile response, making for silky-smooth gear changes with distinctive indention's. The JAWS lock-on grip system worked well, and tied the grip and shifter together as one solid unit, and prevented unwanted contaminates from entering the internals, though I wish the grips were a tad softer. Switching out cables was simple, and only required removing the inner lock ring and cable cover. One minor gripe was that the cable cover sits loosely, and can cause a metallic noise (at least on the alloy version) unless it's braced by the brake reservoir. It available in Black and Silver, and retails for $225.
The X0 Grip Shift is light-years ahead of its predecessor, and offers some amazing technology and features, and everything works together for precise shifting that operates in a smooth as silk manner. You can refer to a full review on the Grip Shift.
The X0 trigger shifter is MatchMaker X compatible, and comes in Silver, and Black, Blue, Red and Gold graphic colors, and retails for $258. It has adjustable forged aluminum levers, forged body and alloy covers. I didn't get to spend much time with the triggers, since I much preferred the Grip Shift system, but I got enough ride time to get a thorough feel for them. In contrast to the Grip Shift, it takes a higher level of effort to switch gears, though the changes offer nice tactile clicks. An excellent thing about triggers, and especially the X0, is the ease and quickness of a down shift, and it only requires a slight dab of the finger to pop down. The forward lever has a nice subtle grittiness to it, so gloves or fingers adhere to the surface without sliding around, even when bumping down a jarring trail. The strong click and movement when shifting gives good feedback, so you are well aware of gear changes, and I never had any sort of over shifting problems.
One of the issues I have over time with their triggers is that the X shaped lock nut on the top cover can loosen along with the lever, and if you don't pay attention, its unscrewing makes the indention (the clicks) soften, which makes the shifting gets sloppy. In addition, when replacing the cable, the complexity of the shifting pod is crazy, so be careful not to have anything pop out of place.
X0 Measured Specs:
The SRAM 2x10 system functions like a fluid machine, and offers quick and smooth shifting, with good durability across most of its components. Some of the highlights of the X0 2x10, are the fast X-Glide shifting technology, Grip Shift shifters, excellent shifting under loads, 1:1 derailer actuation and a quiet drivetrain.
The hollow core carbon fiber cranks are plenty stiff, and their trick separate bolt-on spider makes replacement and swapping out simple. I am extremely happy with the addition of the micro gearing options of 22-36 and 24-38, to go along with the more race flavored 26-39 and 28-42. It makes a granny gear lovers heart go a flutter! Combine the chainring set up with the functional gearing of the 11-36 cassette, and you get a great selection of gears, for any terrain and environment. The cassette has been very durable, and has retained smooth shifting during the entire test period. The chainrings and chain are showing their age after eight months of heavy abuse, and wear and tear is causing some slight shifting issues, so they need replacement. In the case of the chainrings, that entails replacing the complete spider, and although the $140 price seems steep, it isn't bad for two chainrings and a bashguard. The front derailer is greatly improved over its predecessor, and is on par with the competition, and it swung up and down smoothly without any issues. The rear derailer has the excellent 1:1 actuation, accepts the monstrous 36-tooth cog, and offered crisp shifts with a firm detent. The Grip Shift were my favorites shifters, due to their fast, crisp and ease of shifting, though the triggers offered good feedback with their firm and tactile clicks.
I spend a lot of time cranking uphill, on long vicious and unrelenting climbs, and this drivetrain has never let me down. In addition, when pressed hard under extreme loads, such as in technical terrain, it would shift without any undue stress, and would shift whenever required. The nice gear ratio selection, durability, quick shifting and great components make the X0 2x10 a superb system.
SRAM X0 10-Speed Trigger Shifter
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