For years SRAM told me that they didn’t feel the need to make a specific DH drivetrain to rival Shimano’s Saint, instead they felt that their standard groupsets covered all bases. To be fair their regular stuff has always worked pretty well on a DH bike, but I’ve always been a believer that if you make something for a specific purpose it will always be better than something more generic. Maybe SRAM’s reluctance to produce a DH drivetrain was down to the size of the market, I mean sales are always going to be somewhat limited, but whatever the reason was it now seems to have gone away because I’ve just been lucky enough to try out their brand new X01 DH drivetrain, and it’ll be in the shops come April.
I shall cut to the chase…I was seriously impressed with what SRAM have come up with. They’ve managed to produce a drivetrain that performs better than anything I’ve ridden before, and it’s super silent too. Much of the incredible performance comes down to the fact that a huge amount of XX1/X01 technology has been brought over. The X-HORIZON rear mech really does produce the crispest shifting that you’ll ever encounter, the X-SYNC chainring provides excellent chain management, and the X-DOME cassette/XD DRIVER BODY combination results in an extremely light setup and the ability to run a smaller chainring up front thanks to the smaller 10 tooth sprocket.
It turns out that it’s actually a little incorrect to imply that all this technology has been pinched from XX1 because apparently the X-HORIZON rear mech, which is a key part of the system, was in fact designed years ago as a DH specific rear mech. You see the design can only work with a single ring up front, and so for one reason and another the design was shelved for several years until someone spotted the potential to use it as part of a single ring trail bike setup…which we now now as XX1. Finally though the design has returned to it’s rightful home.
So far it might be sounding like there’s no difference between this new drivetrain and the regular X01, but as you can see from the photo above there is one key difference, this ‘DH’ version is 7 rather than 11 speed. Whilst SRAM and Shimano have been gradually increasing the number of our gears for years, DH riders have been crying out for it to go the other way, and so it’s great to finally see one of the companies answering our prayers.
SRAM spent a huge amount of time trying to get this 7-speed cassette right, and after spending a few days riding it I think they’ve got it spot on. At first my close-ratio tuned brain was actually doing too many shifts at once. Up until now I haven’t really noticed it, but so often with a ‘roadie’ style cassette on a DH bike I must automatically shift a couple of gears at once, but when I subconsciously did that with these gears I had gone too far and then had to shift back the other way again. Once I got used to it though I realised that each shift was the perfect ‘step’, and subsequently I found myself doing far less shifting. This can only be a good thing because shifting costs time. No matter how hard you try not to ease off the power when shifting you do, and so the less time spent shifting the better. Also, SRAM reckon that one tooth increments on a road style cassette are more likely to cause damage to a chain when shifting compared to the two or three tooth increments on this cassette.
The exact ratio of this cassette is 10, 12, 14, 16, 18, 21, 24. The small 10t sprocket gives you the opportunity to run a smaller ring up front for added ground clearance, and lower weight, and in terms of overall range I found there was plenty on offer. Even on high speed sections I rarely felt the need to use the 10t, and yet I was still able to ride up some climbs on the way to the test tracks. As I said before I really think this cassette is spot on for DH use, both in terms of the spread of gears and the gaps between them.
Apart from saving weight (this is the lightest cassette SRAM have ever made) and simplifying things, the other bonus of dropping down to seven gears is that you no longer need as much room on the rear hub. As you can see in the photo above there is now a whole pile of room between the cassette and the spokes, and if there’s one thing that bugs me slightly about this new drivetrain it’s that gap. You see if you move the spoke flanges further apart then you can massively increase the strength of a wheel, and it’s something that becomes even more important if you’re running larger wheels. I think SRAM were probably to scared to introduce yet another freehub body design, but I think that’s what this is really crying out for. That way we could either go back to narrower hubs without sacrificing wheel strength, or we could stay at 150mm and have even stronger wheels. I’ve got a feeling that in a few years time we could well see a shorter freehub body which allows us to take full advantage of a 7-speed cassette, and I hope I am not wrong. I normally hate any kind of new standard, but that’s normally because they offer no real performance advantage, but in this case I think it’d be well worth it.
One last thing about this 7-speed system before I move onto the next bit (yes there’s more!), and that’s that it uses an 11-speed chain. I am sure some of you are now shouting “what!?!?!?!?!?”, but SRAM say that their 11-speed chain is the strongest and most reliable chain that they’ve ever made. Wider doesn’t necessarily mean stronger, and from our experience with XX1 over the past couple of years we really don’t think there’s anything to worry about either.
So, now that’s out of the way, what’s the rest of the story? Well, there is of course the carbon crankset that weighs less than 800g, the choice of red or black finish, different cage lengths depending of the chain growth of your bike, and the fact that although SRAM don’t recommend running this system without a full chain guide for DH racing, during two days of riding some properly rough tracks not a single chain was dropped despite no form of chain device whatsoever, but there’s also one other big story, and that’s the fact that there will also be a 10-speed version of X01 DH.
You’ve probably already guessed, but basically the 7-speed version is going to be far from cheap. Exact UK pricing is still to be sorted, but it’ll be very similar to regular X01, and you will of course at the very least need a new freehub body too. The 7-speed system really is aimed at the very highest level, and the price will reflect that. We like the fact that SRAM have produced such a quality product, but what we love just as much is that they will be offering a cheaper alternative from day one. Ok, so you do lose out on the benefits that the 7-speed cassette brings, but crucially you still benefit from the incredible rear mech, and should you wish the narrow/wide chainring (these have always been suitable for both 10 and 11 speed use). The qualities of the rear mech though really shouldn’t be overlooked as the design really does produce the kind of shifting that you’ve previously only dreamt of. If you’re currently running a SRAM 10-speed setup on your bike then the next time you’re in need of a new rear mech we’d definitely recommend considering one of these. We are still waiting to hear back about whether or not you’ll be able to use one of these mechs with an 11-36 cassette, but if you can then it’ll also be an ace proposition for a trail bike.
So, in conclusion I like this new drivetrain a lot, simply because it works better than anything else I’ve ever used on a DH bike. The fact that SRAM are going to be offering a cheaper alternative from day one just makes it even better. I just hope that it isn’t too long before we see rear hubs/freehub bodies that take full advantage of a seven speed system because then we’ll really have taken a big step forward.
To see more photos of the new X01 DH drivetrain click on the gallery below, and if you want to check out SRAM’s take it all then watch the video below the gallery…