I will measure to see if I can fit 650C wheels. Kind of doubtful, from 540mm to 571mm is 15mm difference in radius. If not, maybe I can fit narrow 26" MTB rims 559mm. Or I can stick with 600A (540mm) or go to 520mm.
Terry's website offers a Schwalbe in 540mm.
http://www.terrybicycles.com/Accesso...es-1/rightrun-
Looks like there is a Panaracer Pasela in 520mm - this must be the one you referred to.
http://www.bicycletires.com/ppcpob/p...re_24x1/pp.htm