Rear Derailleur & Cassette
Installing the medium cage rear derailleur that is recommended for use with 2X10 gearing was as simple as installing any other derailleur I’ve used. Once attached to the frame, it’s as simple as setting the high and low limit screws, adjusting the “b-adjust,” and attaching the shifter cable.
All of this is done with an allen now instead of a screw driver, and I will say again that I prefer then new allen heads. Once adjustments were made at the derailleur, it took about 30 seconds of fine-tuning the system with the barrel adjuster at the shifter, and just like that, it’s ready to roll.
Installing the 10-speed cassette is exactly like installing any 9-speed cassette: easy.
The first thing you will notice with the 10-speed cassette and derailleur is how quick, effortless, and precise the shifting is. Just as with the front of the drivetrain, it doesn’t matter if the chain is under tension or not; the shifts are instantaneous and accurate. After four months of riding, this is still the case, and this is by far the best performing SRAM rear derailleur and cassette combination I have used.
(Just to be up front about my biases / preferences: I prefer the shifting feel and performance of SRAM’s system to Shimano’s. Obviously, some people don’t. But in my experience, SRAM’s rear derailleurs and cassettes work better, are more crisp, solid, and consistent, and the whole system is more “set it and forget it” than Shimano’s.)
The new derailleur seems to have a slightly lower profile to it, and, unlike Jeff, I have had no issues with the durability. But I have only been on this system for four months now, whereas Jeff has been riding it for a year. I also don’t ride where there are lots of sticks lying around waiting to get sucked into my drivetrain, and that may have something to do with my experience with this derailleur.
I can say though that I have not had any issues when it comes to grazing the derailleur off a rock or two here in the desert, or when blowing out a corner and doing a drive side slide. So, up to this point, it seems solid, just like the older X9 derailleurs.
As for the cassette, wear doesn’t seem to be taking place any faster then with any other cassette I’ve ever used and shifts are just as quick and accurate as day one.
So is it all good?
2X10 is amazing, have no doubt about that. I will not be going back to a 3-ring front end anytime soon. But I have experienced one flaw in the performance that continues to annoy me. When I’m in rough terrain and shifting between the front two rings, I will often kick the chain off. I have had the chain fall off numerous times to both the inside and the outside while shifting in some rough terrain. This has led to (1) my drive side crank arm being scared up from dropping the chain to the outside, (2) some scary moments, and (3) a new proficiency at getting the chain back on while riding at full speed.
I have tried adjusting both the front derailleur and the chain line, and still run into the same problem. I will note that I never kick a chain when I’m not shifting, and in rough terrain, it only happens when shifting while the chain is getting bounced around. I know SRAM is now offering a 2X10 chain guide called the X-Guide, and I hope to get one on my bike soon to see if it takes care of the problem.
Other than that, I really have no gripes.
All in all I believe that the new 2X10 X9 group is a significant upgrade over any older X9 and X0 9-speed groups, and even holds an advantage over the new X0 10-speed when it comes to price vs. weight / function. Shifting with these components is better in every way over the older 9 speed groups. Durability seems to be on par with the older X9 gear, which from what I have experienced, is at least equal to (but actually, probably better than) most comparable offerings from other companies, including Shimano’s SLX and XT.
If you are building up a XC / Trail / AM bike and you spend a lot of time mixing it up with steep and long climbs and high-speed descents, I would highly recommend using SRAM’s X9 2X10 group.