Originally Posted by
habilis
but on every bike I've seen, rear wheel installation required eyeballing the distance of the wheel between the chain stays and, to a lesser degree, between the seat stays before tightening the axle fasteners.
Haven't you ever used vertical dropouts? It's like mounting a wheel in a fork. You jam it into the dropouts by putting weight on the bike, and tighten the wheel there, giving you exact and perfect placement every time.
Horizontal dropouts, of course, require eyeballing it or using dropout adjustment screws.