10 x 135 to 12 x 142 wheel/hub axle adapters

The Surly Midnight Special uses open face dropouts which are compatible with both standard 12 mm thru-axles &, with the use of their adapters, 10 mm QR hubs.

Although stepping the diameter up from 10 to 12 mm is trivial, you must also increase the Over-Locknut Distance OLD from 135 mm (very common OLD for road & mountain wheels) to the newer 142 mm standard.

These add the necessary 3.5 mm per side, giving a total addition of 7 mm + 135 mm = 142 mm.

There may be some variation in the OLD, but a few mm shouldn't be too big of a deal.

These adapter washers also provide a clearance fit for the M5 QR skewer to pass through. The OD is 19 mm, which I confirmed by measuring the locknut on 2-4 different thru-axle hubs I own. This OD is sufficiently small to allow the tool to install/remove cassette lockrings. The 19 mm OD also is likely to play a big role in locating the hub in many thru-axle dropouts.

Good for emergency wheel replacements.

Keep in mind you need to print a pair - one for each side.

Here are Surly's instructions.

These are untested. I don't anticipate ever testing them myself because I like thru-axles so much.