Mech

The Ratio Mech is the culmination of everything we have learned from five years of designing and manufacturing our own drivetrain components. Through the development of our shifter-modifying upgrade kits, combined with the notoriously challenging riding conditions in the Lake District, we developed a long list of design changes we wanted to make for our own mechanical derailleur. Designed, manufactured and assembled here in the UK, the Ratio Mech has been created from the ground-up to solve these issues.

The Ratio Mech features:

• A user-serviceable and modular design.
• Compatibility with a wide range of shifter and cassette pairings – currently 8 cable fin options with more to follow.
• Optimized geometry for modern 1x cassettes – using a combination of Python modelling and real-world testing the B-gap has been honed to maintain a consistent gap over a wide range of cassette options using two different cage length options. Using a combination of linkage inclination and an offset upper jockey wheel, the Mech tracks the sprockets of the cassette during shifting.
• Rotating components run on stainless bearings, reducing friction and resisting shifting degradation.
• Universal cable routing, without annoying tight bends or loops on any bike.
• Direct Mount configuration compatible with SRAM* UDH compatible dropouts and any cassette. We recommend this option over the hanger version as the stiffness increase over a SRAM UDH hanger is measurable.
• Cage Stop design for efficient wheel removal
• Drag spring clutch to limit chain slap featuring a hardened steel wear surface.
• Spares available on the Ratio website. All changes can be made using a multi-tool, including the removal of the cage which requires one T25 screw and no complicated unwinding of the cage spring.
• Markings and graphics aid in intuitive and simple set up process and on the move tweaks.

Specifications:

• Links, cage plates, mounting bolts and arms machined in the Lakes from 7075 aluminium
• B adjuster plates machined in the Lakes from 6082 aluminium
• Jockey wheels and end caps machined in the Lakes from acetal thermoplastic
• Links and jockey wheels run on stainless Enduro bearings
• Brass, steel and stainless wrap-spring serviceable clutch, machined in the Lakes
• Additive manufactured nylon knuckles made in the UK
• Weight: 340g Hanger/Short, 377g Direct Mount/Long

Looking for service parts?

Take a look at the Mech Service parts product page.

To use the Ratio Mech you will need:

1. A compatible shifter and cassette combination – please see our Compatibility page for details. Or use the dropdowns on the product page to explore. The Mech is not compatible with 2x drivetrains.
2. A frame with either a SRAM UDH compatible dropout or hanger mounting. Not sure which option to choose? See our guide.
3. Chain, chainring and freehub to match the brand and number of speeds of your chosen cassette.

All products we offer for sale on our website are Ratio Technology products unless stated otherwise. All third-party products, company names and logos remain the property of their respective holders and use of them does not imply any affiliation with or endorsement by them.

View our Support page here.

* Ratio Technology Limited is not in any way affiliated with, sponsored or endorsed by SRAM, LLC or Shimano Inc.