SRAM have been pioneers of the 1x drivetrain, and their 1x11 gravel drivetrains (Apex and Rival) have come on many bikes from Bombtrack, Surly and Kona (among many others).
However it's sometimes been the case that the 10-42 or 11-42 cassette that comes on these bikes doesn't quite provide enough gear range to get up really steep hills. Of course it's possible to install a smaller chainring, but this can limit harder gearing.
Enter some creative solutions from a UK company called Ratio Tech. They make kits that allow you to use your existing 11-speed SRAM road shift/brake levers, and match them with a 12-speed cassette (up to 52t large sprocket).
Option 1: Wide Ratchet and Cage Kit
This kit includes a 12-speed ratchet for modifying your shifter, as well as a complete new cage (including pulley wheels) for your Apex, Rival or Force 1x11 rear derailleur.
If you have an existing 1x11 road rear derailleur in good condition, this is the most cost effective method.
Option 2: Wide Upgrade Kit
This kit comes with the ratchet to convert your shifter to 11-speed, as well as a cable fin and barrel adjuster to convert a GX, X01 or XX1 Eagle rear derailleur.
It comes in two varieties, the forward and rear cable exit (this refers to what direction the cable comes out of the derailleur). On some frames that have internal routing through the chainstay, there's not enough room for the cable to exit the rear derailleur at the front and continue into the frame. For these frames, the rear cable exit version is needed. On all other frames, the forward cable exit is probably the right choice.
What else do you need?
To complete your conversion, you'll need a chain, a cassette, and if you've selected option 2 above, a rear derailleur.
The cassette you use depends on what kind of freehub body your hub has - HG (Shimano) or XD (SRAM). If you're not sure, you can check whether your existing cassette has a 10-tooth or 11-tooth smallest cog - HG cassettes will have an 11-tooth cog, whereas XD cassettes will have 10 teeth (this is a rule of thumb, please contact us if you're still not sure).
Here's what you need:
- an Eagle 12-speed chain (the X01 has been shown to have by far the best durability)
- an NX Eagle cassette (if your rear hub has an HG freehub body) or a GX Eagle cassette (if your rear hub has an XD freehub body)
- a GX Eagle rear derailleur (if you're not using your 1x11 road rear derailleur, and so are using the Wide Upgrade Kit - this is not required if you're using the Wide Ratchet and Cage Kit with your existing derailleur) or an X01 rear derailleur if you're using the rear cable exit version.
Keen to go 12-speed?
Send us an email or give us a call, and we can book in your 12-speed conversion.