A great ride right from town would be the same loop that is used for the Copper Triangle ride http://www.coppertriangle.com/course.html
. It's 80 miles with about 6K feet of climbing. Traffic isn't too bad except for the first few miles on the climb up Fremont Pass. You can check out some other climbing routes here: http://cyclepass.com/index_p.html
. If you're more into flats and rollers then just head west along the frontage roads of I-70 and into Glenwood Canyon. Have fun, great time of year here.