The Wasp runs Velocity Aero 451 rims with a SA xrf8 8spd hub and a 48t chainring, using Schwalbe Stevlio 120 psi tyres......nice 'n quick and good handling, and of course no crank clearance problems.
I also have some narrow steel 451 rims which are way skinnier than the stock R20 451 rims, also they have a 5spd cluster which I think is threaded, so a more modern 6 or 7 spd might go on, AND if I can work out how to mount a front derailliuer .....a future project R20??
For my wife's R20 I will be using 406 rims, but I've got 145mm cranks to suit and I will be brazing on mounts for V-brakes front and rear.