Sick of dropped chains? Cockpit too cramped? Not convinced you need 20-30 gears on your mountain bike? If you’re looking for a lighter and simpler setup, it might be just the right time to convert your drivetrain to “1x” (a single front chainring).
Designed to meet the current (and growing) trend of riders wanting to ditch the front derailleur on their mountain bike, the FRM Syncro-Ring uses a single-ring specific design without any shift pins or ramps. The Syncro-Ring employs extra-tall teeth and an alternating thick/thin profile that is designed to interlock with the inner profile of the chain. When paired with a clutch-style rear derailleur, this design aims to keep the chain in place without the need for a chain guide.

Ring_Detail The Syncro-Ring is CNC machined in Italy from 7075 Alloy and it features a black anodised finish as well as laser-etched logos for a high quality and durable finish. It’s available in 30t, 32t, and 34t sizes in a standard 104 BCD, or the smaller 76 BCD to fit SRAM XX-1 cranks.
We’ve been testing the 32t Syncro-Ring on our Cotic Solaris 29er test bike, which converted our 3×10 setup into a sleek 1×10 setup.
Our Take

Being connoisseurs of all things lightweight, FRM build some seriously lightweight components for road and mountain bikes. Our test ring came in at bang-on the claimed weight of 39 grams, which is about 12 grams lighter than the stock SRAM XX-1 ring. Combined with the removal of the front derailleur, shifter, cable and two other chainrings, we dropped a noticeable amount of weight off the bike.
Weight aside, it’s the simplicity and durability of a 1×10 setup that is most appealing. We were able to take a few links out of the chain, which combined with the Shadow Plus XTR rear derailleur, meant that there was absolutely zero chain slap. We also never dropped a chain throughout the test period. Ever. That was despite banging around on a hardtail through boulder-filled rock gardens that seriously tested the limits of our nerve (but didn’t seem to test the limits of the FRM Syncro-ring).
Aside from the quiet operation, we also love the extra flexibility a 1×10 setup provides when mounting a dropper post or suspension remote. We mounted the dropper lever in the position where the front shifter would normally reside.
Our only issue with the FRM Syncro-Ring has been some unsightly wear of the anodising from the teeth, but that’s not an issue that is particular to FRM. Perhaps a raw silver finish would look better in this regard.
Otherwise, we can’t recommend the Syncro-Ring enough. At $100, we reckon it’s a brilliant investment if you’ve ever thought about trying a 1×10 setup. It’s also worth noting that this beautifully crafted chainring is also cheaper than the stock X-Sync rings from SRAM, while the 104 BCD fits most standard triple and double cranksets. – ENDuromag