Can't help you with a shop that rents bikes in Richmond, but can recommend a place to ride. That would be Pocahontas State Park located in the far southwest suburbs of Richmond. I ride there a few times a year and I like the mix of trails. Trails are mainly intermediate with some beginner and advanced sections. Quite a bit of mileage to be had if you add up all the different sections. The two main areas are Lakeview (which has sections 1, 2, and 3), and 'Lil West Virginia (which has a red, blue, and green loops). I like the Lil West Virginia section more, as it has more techy sections and some fun downhill parts as well.
Check out the Trailhead section on this site for more info on Pocahontas and other riding spots in and around Richmond. http://www.cyclingcentralva.org/forums/
Check out the Trailhead section on this site for more info on Pocahontas and other riding spots in and around Richmond. http://www.cyclingcentralva.org/forums/