Like most mountain bikers I started out riding a 27-speed mountain bike with 3 crank rings and 9 gears on the rear cassette. When I bought my 29er a couple years ago I made the switch to a 9-speed, 1×9 drivetrain and despite feeling out of shape and out of gears initially, I eventually got used to the set-up. I even rode 1×9 on my ride from Durango to Moab last summer and only rarely did I have to get off and push. Shortly after that trip I decided to give 2×10 a try and I enjoyed the expanded gearing options, especially for epic rides like the Snake Creek Gap series. But recently I made the switch back to 1×9 – and here’s why.
1. No more chipped chainring teeth. Looking at the outer chainring on my 2×10 drivetrain a couple months back I noticed 3 or 4 chipped teeth, no doubt from bashing into logs and rocks while I was in my smaller ring. With no built-in protection on a typical 2x or 3x drivetrain, chainring teeth are vulnerable and over time broken teeth will degrade performance. When I dusted off my 1×9 crank I didn’t find a single worn or broken tooth, despite easily having a thousand more miles on the crank.
2. Weight savings. This isn’t a big factor but to me it’s certainly an advantage. My basic, 1-ring Stylo crank weighs just 18 grams more than a fancy 2×10 crank with carbon arms and there’s also the obvious weight savings from eliminating the front shifter and derailleur.
3. Less dangerous. In a crash, an exposed chainring acts like a Chinese throwing star hurtling toward your calf and just this week I saw this happen to a friend. Rivers of blood streamed down his calf, the result of about half a dozen puncture wounds. On a 1-ring drivetrain, the chainring teeth are always covered by a chain to blunt any potential impact.
4. Cost savings. No need to plunk down extra cash on a front derailleur or front shifter which easily shaves $100 off the cost of a bike build or upgrade.
5. Fewer controls to worry about on the trail. Singlespeed riders rave about the simplicity of riding without gears and while I certainly don’t think gears are evil, shifting can be awkward, particularly when dropping from a big chainring to a smaller one.
6. Lower maintenance. A 1-by system has fewer cables to route and replace and half as many parts that can potentially fail on the trail. Remember my buddy with the chainring puncture wounds? His crash also completely destroyed one of his shifters.
7. I’m a stronger rider when I ride 1×9. To me this is the biggest advantage, though admittedly I can’t quantify it easily. Still, most of us know singlespeed guys who can kick our asses at the local trail and there’s a reason for that. With fewer “easy” gears to choose from I’m forced to ride harder and push through things that I’d normally spin in an easier gear. Like a crackhead looking for just one more hit, I’ve found that no matter how many gears I have (9, 20, 27), I always want just one more.
Of course there are tradeoffs to going 1×9 so in the spirit of fair and balanced blogging, here are just a couple of disadvantages I’ve identified:
1. A chain guide is essential. It took me about a year before I realized I shouldn’t be dropping my chain so often and with a proper chain guide the problem is solved. Still, this does add weight back onto the bike which takes away from advantage #2 above.
2. Fewer gearing choices. Yep, I still find myself wishing I had another gear (or three!) on some climbs but then again, with more gears I’d have to cross #7 off the list above. On flat trails and road slogs I get dropped by riders with bigger gears which kinda sucks too.
These days component manufacturers are pushing 2×10 drivetrains that basically deliver two rings that are sized in between the three rings on more traditional set-ups and a 1×9 drivetrain just takes things a step further and halves the difference from there. So give it a try – put a piece of duct tape over that front shifter and try using just your rear derailleur – you might actually like how it feels!
Also be sure to check out element22’s article about 1×9 vs. 1×10 for DH riding in case you missed it.