If you've got an 11-speed drivetrain but you're hankering after a 12-speed setup and don't want to commit to a whole new groupset, this retrofit solution from e*thirteen might be just the ticket.
The kit comprises a 12-speed cassette plus a few additional components to upgrade your SRAM 11-speed shifter and derailleur. It's compatible with SRAM 11-speed GX shifters and up, so it won't work with NX. You can also use this cassette with 12-speed setups from Shimano and SRAM.
With a 9t to 46t range, which works out at 511%, compared to 510% on the Shimano 12-speed cassette. It's not a lot more, but it is more. It also scores well on the scales, coming in at 347g. For comparison, SRAM XX1 weighs 360g, and SRAM GX comes in at 447g.
The kit costs $299 or €299, which includes the cassette, a chain, gear cable inner and outer, and all the parts you need to upgrade your shifter and derailleur.
But the crux of the matter is how easy is it to install yourself? I managed it in around 30 minutes, and if you're a reasonably competent mechanic you'll find it fairly easy, but there are a few little issues to watch out for, so watch the video above for a step-by-step guide to installing it.