Machined in the Lakes, Ratio Technology hopes to toughen up T-Type with its SR52T Cage


SRAM’s latest T-type Transmission might be the toughest drivetrain in existence, but nothing is unbreakable, as we found out after bending the mech in our 12-month test. Now though, a small engineering firm in the Lake District has designed an aftermarket cage for AXS T-Type Transmission that it reckons is stiffer and tougher than the original.

Ratio’s cage projects forwards, covering the jockey wheels and it uses two extra bolts for stiffness

Ratio Technology began life in 2018 making shifter upgrade components, and the latest Ratio SR52T Cage is designed for some of the rockiest riding in the UK. The cage uses the same 14 and 16 tooth jockey wheel sizes as SRAM’s, but the leading edge projects further forward and covers the lower wheel, a bit like a bash guard on a chainring.

SRAM GX Eagle AXS t-type transmission

SRAM GX Eagle AXS T-Type is a marvel of engineering, but it is possible to bend it out of shape

Ratio Technology SR52T Cage need to know

  • Aftermarket cage assembly for SRAM’s Transmission mech
  • Designed to be stiffer and stronger than the original
  • Machined aluminium plates and plastic jockey wheels
  • Made in the Lake District
  • Cage only is £74.50, with jockey wheels £94.50

“When T Type first came out we rode it and hit it on a rock and bent it pretty much straight away,” explains Tom Simpson from Ratio. “It felt wrong to just replace it with an identical one from SRAM when it seemed flimsy. To be fair to SRAM they do now make a replacement cage for just £28 though.”

When Transmision launched, a replacement for a bent cage cost well north of £100, with unnecessary parts like the clutch and pulley wheels included. It’s laudable that SRAM introduced a £28 cage-only kit in January though, and you’ll be able to buy them in June.

T-Type comes closer to the ground than any other SRAM drivetrain going

Leading edge design

Ratio says that chamfering on the leading edge helps deflect rocks, while the two additional screws cross-brace the cage to add stiffness. Claimed weight for the SR52T Cage is 90g, meaning a GX mech with Ratio’s cage is 426g without the battery, or some 40g lighter than the standard setup.

SRAM’s view is that the best shifting out there comes from its original and unmodified Transmission drivetrains. We’re also pretty sure that any modifications to its setup will invalidate your warranty with SRAM, so do be aware.

You can buy the SR52T cage with or without the jockey wheels, and in black or silver. It comes with stainless bearings and hardware, while the plates are machined in the Lakes from 7075 aluminium, and acetal thermoplastic jockey wheels. You also get a spare nylon bumper and 3mm security hex for installation.


  • With jockey wheels: £94.50 inc. VAT / USD $98.67 / EUR 91.55€ / AUD $149.24
  • Cage only: £74.50 inc. VAT / USD $77.70 / EUR 72.15€ / AUD $117.65