I recently built my Norco Revolver FS race bike up with 2×11 Shimano XTR Di2 Synchro Shift. There were a few reasons for this. Shimano came on board as a major sponsor for the Subaru-MarathonMTB.com Team, which meant I could afford this kind of premium gear. Secondly, I was in a big accident four months ago that kept me off the bike and resulted in a big drop in strength and condition. Surely building back up to fitness would be easier with access to 28-40 gearing as a low range?
With a 28/40 low and 38/11 high I had the gear spread on my Norco Revolver 29 FS to cover all bases.
Are 2x drivetrains disappearing?
Double chainrings are getting rarer. I recently attended a presentation of Norco’s coming 2018 line-up of mountain bikes, and none of them are being specced with dual chainrings. I think in mountain biking, weight savings and simplicity trump big ranges – most of the time – and cassette ranges are getting bigger anyway. We still see pros speccing dual chainrings for ultra-steep climbfests like Alpentour Trophy and some of the vertical World Cups. Here in Australia, though, there are few races where you’d call dual chainrings a ‘necessity’.
But I wanted to go ahead anyway. I live with my husband Mike in a really hilly area in Brisbane. In fact, we live very close to some of the steepest streets in Australia (a couple adjacent our house hoik up at about 25%). Even our driveway is a heart-breaking berg. We live in Toowong, which is plonked on the foothills of Mt Coot-tha, the Great Brisbane Lump, and our local trails are over on its other side (i.e. you gotta go over a mountain to get to them and back over it to get home). No matter where I ride, there’s hills, and they’re steep, so it makes sense to gear for them.
We have plenty of hills at home – which is useful when preparing for races like Port to Port. c. Tim Bardsley Smith
This was made very apparent after the accident. My FTP, for those into numbers, dropped from about 250 to the low 200s during a 12-week break from training. That’s not so bad, but having been stuck in bed with very limited mobility I lost strength – core strength, upper body strength, stability – all of that. Grinding away at impossible gears does your joints no favours, so while I worked on strength off the bike, I thought double chainrings should help prevent any (new) injuries forming while on it.
Rebuilding my bike was easier than putting my body back together.
Then there was the fact that I was moving from mechanical Shimano XTR to electronic. Shimano’s SyncroShift allowed us to ditch the left-hand shifter (added bonus – I badly injured my left arm in the accident), and save a bunch of weight that way, too. The fact that I could go from 1x mechanical to 2x electronic setup and only be penalised in the order of 20 grams (amongst a few other changes to brakes and rotors) provided the rationalisation that sealed the deal. I had been running a 32-tooth chainring and an 11–42 cassette, and we swapped these out for a 28/38 combo with the Shimano XTR 11-40 cassette.
I already knew I’d love the gearing because I run the same on my wonderful training bike, a Norco Revolver hardtail, which has 2×11 mechanical.
Early in the Di2 build, though, we ran into a problem. The mould for the Norco Revolver FS had been developed after Shimano XTR Di2 2x SyncroShift really hit the shelves, and it had also been optimised for a 1x setup, and when we tried to get the electronic front derailleur to sit low enough to shift properly, it ran into the main pivot, so we had to mount it higher than it should have been.
Anyone used to setting up front derailleurs will know this isn’t optimal.
The result was that instead of the smooth, effortless shift we all love electronic for, I got a huge CLUNK every time I ran up and down the chainrings. We did our best to tune around this via Shimano’s E-Tube Project app, compromising a bit on the ideal gear mapping to try to get a better feel. The shifting improved, but it was far from pleasant.
We set up two SynchroShift modes with S1 and S2, but neither really worked around the design limits of the frame.
Moving back to Shimano XTR 1×11 – but Di2
So my journey through double chainrings using SynchroShift came to a conclusion much sooner than I would have hoped. I want to stress that this isn’t due to a problem with Shimano’s technology – I’ve found that to be user-friendly and superbly engineered – it’s more about just a bit of bad luck – we have frames designed around 1x setups, so I’ll be returning to a single ring, just with the added smoothness, speed and efficiency of Shimano XTR Di2 electronic shifting. And a 30, not a 32, until I grow some glutes back.
All set for heading back to a 1x setup. Although Shimano’s new tooth profile means my chain guide can stay in the spares box!
And remember I mentioned cassettes getting better ranges? Mike has a 11-46 Shimano XT cassette lying around somewhere, and I’ll be interested to try that extended range beyond the 11-42 he’s re-re-built my bike with. Slick electronic shift action is back, and I’ve been playing with a few settings, thoroughly confusing myself by reversing the triggers, and experimenting with different shift speeds.
Ready to roll with a 32/11 high and 32/42 low gear.
It’s good to have options. If I need to save weight I can shed about 110g by running the XTR 11-40 cassette.
Where does Shimano’s 2x drivetrain fit?
There’s still a place for 2x in my heart, and in our garage. That great little training bike I mentioned, my Norco Revolver hardtail, is just perfect with its Shimano XTR mechanical 2x gearing (11-40, 28/38). The bike is plenty light, and anyway, it’s rare I’ll race it so I’m not bothered with trying to drive the weight down.
It is always hard to pass up a light full-suspension bike come race day. Photo: Tim Bardsley-Smith
I use it for all kinds of riding, from singletrack to bulk kays, and that gearing always gets me home. Like I said, there are plenty of bergs on my local training routes, and it’s a great feeling to go out for a training ride knowing that no matter how buckled I am, I can grovel up the steep side of the mountain before the long descent home. Long live double chainrings!
But for now, a single chainring on my race bike.