Ratio Technology has expanded its upgrade kit range to enable the use of Shimano’s 12-speed road cassettes with SRAM 10- or 11-speed shifters, by introducing its new 2x12SH kit.
An upgrade kit to upgrade SRAM 11-speed mechanical groupsets to work with the brand’s eTap AXS chain and cassettes already exists.
This option, however, makes it possible to bypass SRAM’s XDR freehub standard required to use its cassettes. This means you can continue to use your existing wheelset. SRAM 10- and 11-speed road bike groupsets relied on a Shimano HG freehub body.
Included in the kit is what Ratio calls a 12SH Ratchet, which the brand says is designed specifically for the tooth positions on Shimano’s 12-speed cassettes, as well as replacement pulley wheels for the rear derailleur.
The 2x12SH kit will retail for £99.50 / $120.80 / €114.30 / AU$191.30
What’s included in the kit?
Both pulleys roll on stainless Enduro bearings and Ratio says they are machined in-house from acetal thermoplastic. The upper pulley is offset slightly to help SRAM 11-speed derailleurs cope with the increased width of the 12-speed cassettes.
The kit is also compatible with SRAM 10-speed road bike shifters, with the addition of a Ratio Cable Spool to enable the 12SH Ratchet to install onto it.
32t maximum capacity
Ratio Technology says the maximum tooth capacity is strictly 32, the same as SRAM’s road WiFLi derailleurs. This means you won’t be able to pair a Shimano 12-speed mountain bike cassette with the system.
Of course, some Shimano 12-speed road cassettes are 11-34 and 11-36 (the only options on Shimano 105 Di2). Ratio Technology doesn’t officially endorse pairing its kit with these cassettes because “the B-gap can be slightly affected”.
The brand says it also tested SRAM’s MTB Exact-Actuation 10-speed derailleurs with the 11-36 cassettes and found that “some derailleurs don’t quite have the sufficient range of movement to shift properly across the width of the Shimano cassettes”.
Why might riders want to upgrade?
SRAM’s 11-speed road and gravel bike groupsets represent the last of the brand’s offerings in a mechanical variant.
With the exception of the recently announced Apex Eagle (which utilises a mullet drivetrain), SRAM’s road and gravel 12-speed options are all electronic groupsets.
By enabling previous-generation SRAM 11-speed mechanical groupsets to work with 12-speed cassettes, this effectively offers riders an up-to-date mechanical option without the hassle of sourcing a wheelset that’s compatible with the brand’s XDR freehub.
