Originally Posted by CdCf

Yes, the brake locations are rim-size specific. A 700C rim has its brake surface approximately 30-31 cm from the hub, while a 26" rim is smaller, and expects a brake pad at about 28 cm from the hub. If you mount 26" wheels with brakes mounted at the proper location for a 700C rim, the brake pads will end up scraping the top of the tyre, and miss the rim completely...

Disc brakes require only a disc brake mount on the fork (and a disc brake-compatible hub/wheel), so they're independent of wheel size. Too bad the LHT doesn't have them. Big mistake by the Surly guys, in my opinion. I guess that spare spoke holder made more sense to them...