It has been several years since I reconfigured my mountain bike to run a single chainring and I haven’t looked back since. Even running an old 9 speed rear setup alongside the single front, hasn’t caused me any issues. So with the advent of SRAM proclaiming the greatness of 1x and now offering single ring conversion options for road bikes it’s been something I’ve been considering for most of this year. September is my birthday month and so having received some birthday money I went ahead and bought myself a SRAM Force 42T X-sync chainring to fit to my existing crank.
On my mountain bike it’s been rare that I’ve ever felt the need for another gear at either end of my range and that’s with a 9 speed 12-36 cassette. Only when riding on the road do I feel the need to go up another gear and I never need to drop down lower than my 32/36 ratio, even on the steepest of off-road hilly ascents. On the road bike locally around Cambridgeshire I’ve been finding that I could leave my road bike in the 50T chainring and never shift down to the 34T, even where there are a few small hills they really aren’t that significant, so I decided that a single ring ought to be a viable option.
So that brought me to deciding what size to buy. Obviously you don’t have to stick forever with the chainring that you choose to start with. In fact for certain riding e.g. in hillier areas of the country it might be sensible to switch the chainring out for something smaller and in flatter area have something available that’s a bit bigger. So do I stick with a 50T and effectively just drop the additional 34T? That of course would be an option and in future I might invest in having a 50T as a flat roads alternative. It’s only takes five bolts to swap it out after all. But no, after looking at some gear ratio calculators on the web to see how many ratios I’d be missing and what speeds I’d still be able to maintain at 100 rpm cadence, I came to the conclusion that I’d be able to ride a 42T ring and an 11T cassette sprocket comfortably at speeds of up to 25 mph. And for the time being the 42/28 lowest gear should be OK for all but the absolute steepest of climbs; when my current cassette wears out I’ll probably switch to something wider ranging like an 11-32 so I don’t feel like I’ll need anything smaller, so a 42T it is then!
The SRAM Force X-Sync chainrings are available in either 110 BCD or 130 BCD depending on whether you are fitting them to a ‘compact’ or ‘double’ crankset. My bike came with a compact chainset so 110 BCD is what I required. The 130 BCD rings are only available in the bigger sizes 52T and 54T, whereas the 110 BCD is available from 50T down to 38T giving a much greater range. You can also buy 1x chainrings in the lower spec Rival range as well as Force, which is what I’ve got in most places on my bike (shifters, brakes etc), however when I was buying, due to end of summer sales, Force was actually less expensive. Shop around! The Rival chainrings aren’t available in 130 BCD by the way. Of course if money is no concern, you can also just buy an entirely new 1x chainset instead; this will also make things look more ‘pro’ too.
You don’t have to buy SRAM to buy into the single ring concept, but it is in my opinion a good idea. The X-Sync rings have a slight offset built in, so you’ll end up with a chainline midway between your previous big and small rings, which allows for smoother use of all the sprockets on the cassette and no doubt reduces wear and noise. SRAM also provide a set of washers designed to allow you to keep using your original chainring bolts, otherwise you’d need to buy shorter bolts as they only need to fit through 1 chainring. This is useful to have and makes fitting the chainring really simple. As you can see from the photos, I’m successfully using the SRAM ring with my original MEKK own-branded crankset.
Additionally I removed my front mech and the cable from there to the shifter as these parts are now no longer needed. The SRAM Rival 22 left shifter doesn’t go floppy or rattle or anything untoward without the cable which is nice. Apparently you can remove the shift paddle from the lever assembly if you wish too, but it’s not necessary. The experience on the bike is excellent. The whole drivechain seems to run smoother and with no front mech cage to rub against I can happily use all of the gears on the cassette with no nasty noises. I also don’t have to think about getting in the right chainring ahead of the next big hill or changing up over the top ready for the descent anymore. Aesthetics of course are a personal thing but I like the clean lines of the single ring setup, it also means you can clean around that area much more easily as well. The only downside is that steep hill are now tougher but I’ll just have to get out of the saddle more often and flex those muscles.