Surly wants you to be able to set up you ride just the way you want it. This pair of adapter washers make it so you can throw your favorite 135, 170, or 190mm O.L.D. 10mm solid axle hub into the rear end of a 142, 177, or 197mm spaced thru-axle frame. Add the adapters, add the wheel, install and tighten the nuts and, bam, you're ready to rip. Make sure the solid axle on your wheel is the right length for the frame spacing. For instance: 190mm OLD QR goes with 197mm thru-axle spacing.