A common front wheel tire size for SWB 20×26 recumbents — a 20″ wheel with a 1.5″ tire — is often missing from the Cat Eye cycle computer tire size chart, making it a bit of trouble to set up an odometer. (A 20″ wheel with a 1.5″ tire gets a setting of 1490 mm, by the way. A 20″x1.35″ tire has a “rollout” — a setting — of 1460.)
Since bent riders frequently mess around with “odd” size wheels, the following tire size chart from the Cat Eye knowledge base is helpful. (Go straight to the downloadable PDF “Tire Size Chart.” The last time I looked, the link to the graphical table was missing.)
Actually, while I’m at it, the short knowledge base index is worth a link. Many common problems answered. Also provides a procedure for measuring “tire roll out” so you may callibrate your computer to your tire.