I don't know about rentals, but Zach Kaplan in Alameda will let you go on very long test rides. He charges a nominal fee for it.
Zach is a good guy and a very knowledgeable recumbent dealer with a great selection of 'bents. I bought an Rans Rocket from him a year ago and love it.
Good luck, rich
Zach Kaplan Cycles
1518 Buena Vista Ave.
Alameda, CA 94501-1218 USA
510-522-BENT (2368) [email protected]