The Ratio Technology Mullet Drivetrain: 1×12

I love 1x drivetrains. And I love mullet. (Mullet = combination of road and MTB components.) Whatever the reason – maybe it’s the simplicity, maybe the minimalism in the technical structure – I’m fascinated by drivetrains without front derailleurs.

Ritchey Swiss Cross Force CX1

Before Christmas holidays I started a new 1x project: An allyear / allround / allweather bike with road genes but also suitable for off-road use. The frame choice was based on the legendary Ritchey Swiss Cross steel frame. This has to do with my preference for diamond frames made of steel, but also with the fact that apart from the new T47 standard bottom bracket, only BSA screwed bearings are ok for me.

Mullet Solutions

A mullet drivetrain is a solution that mixes road and MTB components. Actually, the aim is to be able to use cassettes with large bandwidths (bandwidth = the ratio between the largest and smallest sprocket in percent, e.g. 40/11 * 100 = 364%). The larger the bandwidth, the larger the jumps between the individual gears – not ideal if you want to achieve constant cadence. This can be remedied by a higher number of sprockets. So for example. 1×12, 1×13 or even 1×14.

12, 13 or 14 sprockets

In 2020 Campagnolo presented a 1x drive with 13 gears: the Ekar. A top gravel group at a reasonable cost. The possible gear ratios also cover a wide range and so this is a very good solution if you like Campagnolo and if you want to change the entire system. If you like the exotics as a whole, you could also take a look at the rotor group with hydraulic rear derailleur or contact Stocky’s racing technology. Dirk Stock knows all about technology and builds custom solutions for little money even up to 1×14, i.e. 14 gears.

But if you want to stay true to the brand, SRAM (like Shimano) has 1×12 solutions on offer. With SRAM this is called AXS and it’s electronically controlled, in the MTB area there are the EAGLE groups in the mechanical variant and also as AXS. And this is where it gets interesting when you think of Mullet: Road Shifter and MTB rear derailleur or cassette or the road AXS variant.

The 1×12 mullet drive with mechanical rear derailleur from SRAM

If you want to use the electronic system from SRAM (it’s also a question of price, of course) then there are technically simple solutions – the AXS Eagle Systeme für MTB and AXS Road are compatible and so you could use the Road STIs with the Eagle rear derailleur and thus have Cartridges available up to a bandwidth of 520%.

The non AXS 1×12 SRAM Solution

The solution, which SRAM does not offer itself, but which seems attractive to many owners of SRAM drives, is the possibility of switching a 12-speed cassette (such cassettes are available from SRAM itself but also from many other manufacturers such as Garbaruk) with SRAM Road STIs . The STIs from the Rival, Force and Red Editions are all designed in the mechanical version only for 11-speed circuits. The solution to this problem comes from the UK: from Ratio Technology.

Ratio Technology SRAM Upgrade to 12 Kit

The small English company is building a relatively simple solution for “the human powered wide-range 1×12 drivetrain”. The central element is a 12-speed ratchet specially developed for Eagle ™ rear derailleurs (including cable router). In 2021, a system is to follow with which you can then switch Road AXS cassettes (with a normal CX1 rear derailleur). This then expands the possibilities again – especially with the new Wider Gearing Cassette.

Upgrade example from 1×11 to 1×12 with the ratio kit

Die SRAM Eagle 12fach Kassetten setzen einen SRAM XD Freilauf voraus, da die kleinsten Ritzel 10 Zähne haben und der Shimano HG Freilauf nur 11 erlaubt. In den folgenden Tabellen hab ich versucht, einen Überblick über die Varianten zu geben, die sich stand heute realisieren lassen. Diese Liste ist nicht umfassend sondern subjektiv für meinen Road/Offroad Einsatz eine gute Auswahl. Ich habe mich dabei auf Kassetten von SRAM und Rotor (die Rotor Kassetten sind optimal mit AXS Shifter zu schalten) beschränkt.

The SRAM Eagle 12-speed cassettes require a SRAM XD freewheel, as the smallest sprockets have 10 teeth and the Shimano HG freewheel only allows 11. In the following tables I have tried to give an overview of 2 variants that can be implemented today.

12x cassettes

The Ratio Mullet drivetrain in operation

In the end I couldn’t resist and had to order the Ratio conversion kit from the UK (thanks to Brexit: waiting time around 1 month). The installation can be mastered with a little experience and in the end the setup works perfectly.

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The components are now a Rotor DM crank with 46 teeth chainring and at the other end a Gabaruk 12-speed cassette with 10-48 teeth, especially good for the climbs around here like the Steinbergalm. Shifting is done by mechanical a SRAM Force lever and a converted SRAM Eagle GX rear derailleur.