SRAM doesn’t do a 1×12 mechanical road drivetrain — so someone else did

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SRAM’s Red eTap AXS and Force eTap AXS wireless electronic 1×12 “mullet” drivetrains work really well, offering quick and reliable shifting, easy wireless setup, and heaps of range in a single-chainring format that’s highly appealing to the burgeoning gravel and adventure crowd. However, both setups are also quite expensive, and while the company has long offered far more affordable cable-actuated 1×11 drivetrains, none of them come close to offering the range that you can get with the 12-speed setups.

SRAM has yet to announce — or even hint at — a pending update of its drop-bar mechanical groupsets to 12-speed, so UK outfit Ratio Technology has stepped in with a modestly priced retrofit kit that looks to be quite the hit.

Ratio Technology’s modestly priced kit comprises a new 3D-printed stainless steel ratchet ring that adds an additional click to an existing SRAM DoubleTap 11-speed lever, a new 3D-printed reinforced nylon cable fin for the now-matching 12-speed SRAM Eagle mountain bike rear derailleur to properly line up the new cable pull ratio, and a few other small bits to facilitate the conversion (like a barrel adjuster and some hardware). The conversion will supposedly work with any SRAM Red, Force, Rival, Apex, or S-Series 11-speed road lever, although the derailleur needs to be either a GX-level model or above.

The kit consists of just a handful of bits, but the pricing is similarly modest.

There’s also some elbow grease required to install those bits, but the company has provided clear video instructions for the process, and having done a similar service myself, I can attest that it’s not terribly difficult at all. Ratio also strongly suggests that there be at least 70 mm of distance between the center of the rear derailleur mounting bolt and the nearest housing stop (or exit point in the frame for internally routed frames) so as to maintain a smooth cable path.

And just so we’re perfectly clear, you’ll have to source your own SRAM 11-speed lever, of course, as well as the corresponding SRAM Eagle mountain bike rear derailleur, 12-speed chain, and compatible crankset.

“We set up Ratio to make some radical improvements to a specific area of bicycle technology, and you might hear more about this sometime in 2021,” said company co-founder Tom Simpson. “In the course of our prototyping, we found ourselves discovering the benefits of 1x drivetrains while also having to make prototype shifter modifications. From there, it was clear that the missing piece of the puzzle in currently available drivetrain options was an affordable, truly wide-range 1x groupset for use with drop bars.

“There are fixes out there, but nothing seemed to leave the setup as neat as the original had been. We love SRAM’s 1x systems, so we put together a simple kit to run our existing 11-speed shifters with 12-speed Eagle drivetrain components.”

The installation process might appear daunting to some, but it’s actually quite straightforward.

“From my perspective, I’ve never thought the front derailleur was a great solution to getting more range,” added fellow company co-founder Felix Barker. “Wide-range 1x gets rid of the front mech but keeps the range. For road riding and racing, the ratios between gears aren’t currently close enough to work well, but for gravel, cyclocross, and bikepacking it works really well (as long as your mech hanger is straight). We really liked the idea of providing a much lower-cost solution and allowing people to get more from parts they already own.

“In terms of making it happen, to SRAM’s credit, they design a lot of their components in a way that makes them possible to disassemble, service, and now (with a bit of help from us) upgrade. Their mechanisms are also impressively simple and so are not too intimidating for a home or shop mechanic. That made an upgrade kit for SRAM 1x components a possibility. To design the parts required a lot of careful measuring of SRAM’s components, some fairly complicated math to get the right cable fin profile, and then the fun steps of design and testing.”

Sound interesting? We certainly think so, and have a kit inbound for testing. Retail price is a reasonable US$61 / AU$96 / £50 / €60, with prices including shipping and VAT for UK and EU regions, and other destinations subject to local import duties and fees.

As appealing as Ratio’s kit seems, though, its mere existence only serves to cast a brighter spotlight on the elephant in the room: if it’s so easy to adapt SRAM’s current 11-speed drop-bar levers to work with the company’s own 12-speed Eagle rear derailleurs, why hasn’t SRAM done so already? After all, it certainly seems as if there’d be a market for such a thing, and if nothing else, there’s been a growing groundswell of support for SRAM to at least update its existing 2×11 mechanical road drivetrains to a more modern 12-speed setup, including an option for a 1x configuration.

Perhaps SRAM is already working on it?

Maybe that’s the case, or maybe it isn’t, but in the meantime, you can find more information on this aftermarket retrofit kit at

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