What level of riders are you? How much time do you want to spend on the ride? We have a variety of areas to ride in.
http://www.blm.gov/nv/st/en/fo/lvfo/..._rock_nca.html
This is the best place to see wild burros.
River Mountain Loop
http://www.rivermountainstrail.com/t...p/rmtpmaps.htm
This would be about 10 minutes further away from the journey to Red Rocks. You can also access Valley of Fire from the Lake Mead area. You will have a good chance to see coyotes and bighorn sheep as well as Lake Mead and if you like, Hoover Dam and the Pat Tillman Bridge.
Something else to check into is a bike shop
http://lasvegascyclery.com/
I know that they have transport vans and might pick people up on the Strip. I'm not sure, just thinking out loud.