Last month I posted Part I of my review of the new SRAM X0 2×10 mountain bike drivetrain and this week I’m ready to talk about my experience with the X0 derailleurs and shifters. In my opinion this is where good drivetrains are separated from great ones – where each click of the thumb either inspires confidence or is followed by a wince and a curse.
X0 Rear Derailleur (10-speed)
Since 10-speed systems have tighter tolerances than standard 8- and 9-speed drivetrain components, I decided to have my local shop hook up both front and rear derailleurs and laced each with Gore Ride-On cables instead of the included SRAM cables and housing (which are high quality, no doubt – just not quite as robust and friction-free as the Gore cables).
The X0 rear derailleur shaves about 12 grams off the weight of the X9 and features a carbon fiber composite outer cage that I’ve found to be tough as nails. The X0 also features low maintenance sealed bearings (unlike the bushings found in the X9) which should last for a very long time. The result: smooth, consistent shifting even under load.
Prior to upgrading to the 2×10 X0, I was running a short cage X9 rear derailleur and after just a few months I had downshifting issues (up-shifts worked great but the derailleur wouldn’t return on release of the cable tension). After several visits to the shop the best explanation seemed to be that the spring was faulty which meant I needed a new $90 derailleur. Based on this experience, while testing the X0 I paid close attention to down-shifting performance and found the spring action to be both powerful and reliable, even after hundreds of miles in the saddle.
Mud didn’t seem to affect the performance of the X0 rear derailleur and thanks to the simple design, cleaning was a cinch after particularly nasty rides. In icy conditions, however, the derailleur tended to freeze in place, effectively limiting my gear choices to just 2-3 cogs. In each case, a layer of ice encased the entire unit; once melted, the derailleur was back to normal.
SRAM is known for the 1 to 1 actuation ratio in their derailleurs and shifters and for those who aren’t familiar, the idea is that the amount of cable movement equals the amount of movement at the derailleur itself. The upside is the derailleur is easier to install and configure plus it’s less likely to need adjustment down the line. I’m sold on that last part by itself – I hate fiddling and worrying about derailleur adjustments. Since installing the X0 on my bike I haven’t made a single adjustment.
X0 Front Derailleur
My 29er mountain bike didn’t originally ship with a front derailleur so I was a little concerned the X0 wouldn’t work well with my frame set-up. Fortunately SRAM has almost every conceivable configuration covered – from high to low clamp, low to high direct mount, and even 3 different down tube diameter clamps. On my bike the derailleur cable routing comes dangerously close to the rear wheel (around half an inch with 2.2 tires) but even after muddy slogs I haven’t had any issues with cable snags or dings.
The front derailleur responds quickly to both up and down shifts with a decisive clunk. Thanks to the X-Glide ramps on the X0 crank there’s virtually zero shifting delay for fast, smooth transitions between high and low gears (and vice versa).
On a few rare occasions I did manage to drop the chain off the outside of the crank and during the final muddy Snake Creek Time Trial I experienced the dreaded “chain suck” heading into two of the climbs. Of course the front derailleur can’t be faulted for chain suck – more than likely the mud, combined with wear on the crank teeth is to blame. Fortunately I was able to catch the issue in time before damaging the derailleur or chain.
The X0 trigger shifters are compact and lightweight (232 grams) with a great, responsive feel to them. The shifters are even adjustable for a custom fit which means no more uncomfortable reaching for those with small digits. My set of shifters is 2×10 specific meaning the left shifter only has 2 index positions so it’s not compatible with 3x systems. Some may be disappointed to know SRAM isn’t currently offering a 2×10 grip shift option (or “twist shift” as they’re called now).
Mounting the X0 shifters was a cinch and I really like how little space they take up on the bar. Of course the shifters tuck in nicely with matching X0 brake levers and they’re also MatchMaker X compatible for those who have bought into the whole system approach.
Throughout my testing over the last 6 months+ I haven’t had to adjust a single setting on my shifters. In fact, I really haven’t given them much thought because they’re so dependable with a natural feel. All bike components should aspire to this level of performance and fit!
X0 Drivetrain: Overall Impressions
SRAM has put together an impressive set of technology and manufacturing precision to produce the X0 components and it shows. And while the 2×10 paradigm may not be for everyone, I’m confident that most riders will find the system meets their gearing needs while simplifying the entire experience – from maintenance to performance on the trail. After all, wouldn’t you rather spend more time just riding than working on your bike or trying to find the right gear combination during the ride?
Compared to the other SRAM component groups, the X0 is really meant for the competitive rider who is looking to save weight by making use of the latest materials and designs. And while I’m no competitive rider myself, I really appreciate the weight savings on those long days in the saddle and pretty much every time I lift my 29er onto the top of my car. The X0 blends those weight savings with reliable, durable performance, making it well suited for training as well as racing.
Get the X0 2×10 drivetrain and you’ll being sending XOXO to your bike too.
Thanks to the folks at SRAM for providing the X0 drivetrain for review.