I wrote my initial review of the X01 DH 7 speed drivetrain a little over a year ago. Since then, I’ve spent quite a bit more time on it and have come to some realizations.
My conclusion last year was that it’s the best performing DH drivetrain on the market, but it’s expensive, and it has some durability issues. To some extent, SRAM has addressed the price issue – they released the GX DH drivetrain, which is quite a bit cheaper than the X01.
But that leaves the durability issue. As I noted in my initial review, my problems were with the derailleur. I snapped the B-set plate after four days on the derailleur, and so far this summer I’ve gone through 4 of those plates. The longest I’ve gone without breaking the rear derailleur was four days.
And to be clear, the derailleur never broke because I hit it on something. My chain wasn’t too short, and everything was adjusted properly. I even tried a stainless steel B-set plate from “The Fix” in Whistler (it lasted 2 days, and it took out my derailleur hanger when it broke).
Added to those issues is the fact that I have to dump biblical proportions of loctite on the derailleur hanger bolt to keep it from rattling out of my frame. With a “normal” amount of blue loctite on the bolt, I generally have to re-tighten the derailleur every other run.
Every other piece of the drivetrain has performed flawlessly, but in my opinion the derailleur is complete junk. From talking to a number of mechanics in Whistler, it’s pretty clear that this is common problem, so I set out in search of a solution.
After cross referencing some gear actuation ratio tables, I’ve found a solution: with minor modifications, a Shimano Saint derailleur works well as a replacement. I’m now running a SRAM X01 DH 7 speed shifter, cassette, and 11 speed chain with the Saint M820 derailleur. It shifts very nearly as well, and I don’t have any of the issues that I had with the X01 DH derailleur.
All that needs to be done to get this setup to work is to add a ~2 mm spacer under the cable pinch point. This slightly reduces the amount the derailleur moves on each shift, which works perfectly for mating it with the 7 speed shifter and cassette.
Aside from resolving the durability and rattling loose issues, the Saint derailleur is also a bit slimmer, and tucks under the chainstay a little more cleanly. And if you don’t want to pay for a Saint derailleur, this modification will work with and Shimano 10 speed Dyna-sys derailleur.
There’s a lot of upsides to the X01 DH drivetrain that I laid out in the initial review, but the durability issues were beyond frustrating. Incorporating the Shimano derailleur resolves that issue, and if you’re buying the drivetrain new, the Saint derailleur costs almost half as much as the X01.