Ratio 12-speed gear kit review

Ratio’s range of kits let you switch up your 11-speed SRAM shifters to run a 12-speed road or even Eagle MTB cassette and who doesn’t want that?

Ratio 12-speed gear kit derailleur pulley
(Image: © Guy Kesteven)

Cyclingnews Verdict

A super-simple way to get the latest SRAM ratio gains from your ‘obsolete’ SRAM cable shifters and it’s not even hard to install - it will void your warranty though


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    SRAM 12-speed road, XPLR or MTB gear compatibility

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    Works with all SRAM 1x11 (and some 1x10) shifters

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    Different kits for different cable routing

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    Way cheaper than going AXS


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    You’ll also need an MTB mech to go Eagle

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    Installation can involve some juggling

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UK company Ratio wanted to access the excellent range of SRAM 12-speed gearing with road bar shifters without having to go wireless. So they took SRAM’s 11-speed road shifters and created a conversion kit which was followed by a whole range to cover every possible combination of cassette and cable routing. As long as you get the right kit for the SRAM road groupset setup you’re trying to achieve (and Ratio have a very comprehensive and honest guide on its site to make that easy) and you’re patient installing the various kit parts, it’s an easy DIY job. We’ve installed both the Eagle and 10-36T road kits and so far and we couldn’t be more impressed with how well they work.

The parts included in the Ratio 12-speed gear kit for a road bike

The kits come with all the parts needed for your specific drivetrain setup (Image credit: Guy Kesteven)

Design and performance

The key component of the Ratio kit is the small metal 12-speed cam that you switch out for the existing 11-speed cam on any SRAM 11-speed cable shifter (or any SRAM 10-speed shifter if you also use Ratio’s Cable Spool). Fitting this is a bit of a faff as you need to unbolt the shifter from the bars and it’s a lot easier if you also give yourself enough hose free from under the tape to handle the lever properly or unplug the lever from the brake line and remove it completely which is a big pain on a hydraulic system. Once you’ve got the shifter free though all you have to do is unscrew the grub screw that holds the axle the shifter mechanism together and then pull it out using the screw Ratio provide in the kit. You then carefully remove the spool, take the existing ratchet segment off and replace it with the Ratio one. Carefully click it into the seventh position then wiggle and slide everything back into place, re-pierce it with the axle, fit the grub screw, bolt the lever back onto the bar and in terms of shifting you’re good to go.

Ratio 12-speed gear kit being fitted to an 11-speed SRAM lever

The key component is swapping the shifters existing cam with Ratio's 12-speed cam (Image credit: Guy Kesteven)

Things do get slightly complex at the far end though as you’ll need to work out exactly which kit and/or derailleur you need to get everything working. In the case of the wide range kit I fitted to my tandem to handle a 10-52T Eagle cassette, it needed an Eagle compatible MTB derailleur of GX level or above and the 1x12 wide upgrade kit with fresh fin and barrel adjuster (a simple circle and Allen key job) for the ‘Exact Actuation’ cable ratio. As the road conversion works with a road rear mech there’s no need for a different fin but you do need to swap the jockey wheels for the ones Ratio provide.

You might find you need to juggle the mech screws a bit to get the clearances right and get everything shifting sweet but once that’s done you’ll barely notice anything different in the shift feel compared to an 11-speed system. It’s possibly slightly sharper in feel but then that’s probably because our Force shifters were ancient so you’re potentially not just upgrading to an extra cog (and potentially 10-44/50/52T cassettes if you go mullet/Eagle) but also getting a sharper shift set up. While we’ve only been using the kits a short while we’ve experienced nothing to suggest reliability is compromised either but obviously as soon as you start getting intravenous with your shifters or pulling mechs apart you’ll void your SRAM warranty if there’s any left.

Ratio 12-speed gear kit fitted to a road bike

Despite adding a gear, shifting performance is unaffected (Image credit: Guy Kesteven)


We’re massive fans of the wider gear ranges and smaller cog shifts offered by the 12-speed cassettes of SRAM’s Eagle, XPLR and road ranges. Ratio lets you access those gains from existing 11 (and some 10) speed cable road shifters with nothing more than some small component swaps and a bit of patience and the results are awesome.

Tech Specs: Ratio 12-speed gear kit

  • Price: £66.50 - £94.50
  • Weight: Negligible change to stock items
  • Options: 1x12 road, 1x12 wide rear or front cable exit

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