Driven by the success of SRAM's XX1/X01 wide-range 1x11 drivetrain, a number of aftermarket solutions that modify existing 10-speed drivetrains have recently seen the day - all based on adding a larger cog (40 or 42t) to an existing 10-speed cassette, and removing one of the middle cogs in said cassette to make room for it. OneUp Components was one of very first companies to offer such a solution, which now also includes a bespoke 16t cog to help smoothen out the gap caused by removing the 17t cog (which is usually the cog recommended for removal when modifying a cassette to accept the addition of the 40 or 42t cog).
We tested OneUp's original 42t cog offering (swapping the 15t for a 16t cog as well), and although we enjoyed the wider range of our drivetrain, we were less than impressed by the somewhat sloppy shifting that the modifications resulted in, as well as the larger jumps in gear ratios in the middle of the cassette. You can read our full review of the OneUp cogs here.
To further improve the performance of modified 1x10 drivetrains, OneUp is now launching the RAD cage - a Shimano-specific replacement rear derailleur cage for medium-cage (GS) 10-speed derailleurs. The RAD cage is specifically designed to accommodate the larger 42t cog without having to add a longer B-screw, and it also seeks to optimize the path of the upper pulley wheel to ensure it stays closer to the cogs in order to provide optimum shifting performance across the full range of the modified wide range cassette.
The key feature of the RAD cage is the offset upper pulley wheel. Instead of the pulley wheel axle being inline with the cage pivot, it has been moved rearward, which means that as the cage rotates to take up or provide slack in the chain as the derailleur moves it across different sized cogs, the upper pulley wheel also moves closer or further away from the cassette (mimicking the movement of SRAM's X-Horizon design found on XX1/X01/X1 to a certain extent). This positions the upper pulley wheel for optimal shifting performance in any cog, and also creates more chain wrap in the smaller cogs which is good for drivetrain longevity. This is the trick that allows the RAD cage to function with a normal B-screw on Shimano derailleurs. Note that SRAM 10-speed derailleurs work better with the 42t cog out of the box, due a slightly different derailleur architecture, negating the need for replacing the cage. It would be a moot point in any case, since SRAM derailleurs do not feature replaceable cage architecture to begin with.
On paper, the RAD cage certainly looks likely to address some of the concerns we had when testing the OneUp 42t cog. With the 16t replacement (now included for free with any 42t OneUp cog purchase) and the optimized cage, we can see the drivetrain performing at an acceptable level and thus taking another step towards providing wider 1x drivetrain solutions at a significantly lower cost than any of the complete solutions available today. We are currently testing the RAD cage to see how it performs in real life and will have a review available shortly. In the meantime, check out the specs and a couple of informative videos below:
OneUp Components RAD Cage Highlights
- Price: $35 USD (shipping July 1st - available to order now at oneupcomponents.com). Price includes taxes and duties in the US and EU. Shipping is free worldwide for all orders of $70 or more.
- Material: 7075-T6 Aluminum
- Weight: 26g
- Colour: Black
- Compatibility: Shimano GS (medium cage) Shadow+ 10spd clutch rear derailleurs:
- Deore (RD-M615 GS)
- SLX (RD-M675 GS)
- XT (RD-M786 GS)
- XTR (RD-M985/RD-M986 GS)
Installing the RAD cage is a fairly straightforward process for anybody who already wrenches on their bike a bit. No specialty tools are required.