Nice approx. 350km day trip starting in Calgary by Canada Olympic Park, out the Trans-Canada then out the 1A by Cochrane and then down Highway 40 through Kananaskis (Gas stop between beginning of highway 40 and Smith Dorian Trail) next, on to Blackdiamond for another pit stop, perhaps some food and beverage, from there on through to Bragg Creek (can stop again if you want as there are some nice pubs and restaurants here or maybe just an ice cream if it is hot) and then on back to Calgary stopping at the West Hills area.
The road is nice with mountain sections, winding rural roads with a variety of conditions to keep it interesting. Along Highway 40 there are often some wildlife sightings as well...
Be aware in the spring as the wildlife is often on the road in a couple areas... you do generally have lots of notice when they are out though.
Keep in mind the barricade at the Smith-Dorian Trail closes off from December 1 - June 15th so you would have to turn back or go around another way, the Smith-Dorian Trail is a gravel fire road with some fun riding as well and it ends in Canmore so this can be an option if the roads are nice and it is not yet (eg. before June 15th.)
The rest of the year this loop tends to be a favorite of the local bikers.