Turnagain Arm Trail and Girdwood
Put bike on back of van and take the he Turnagain Arm Shuttle to either Girdwood or Portage. Either bike all the way back to Anchorage 45 or 55 miles, or bike from either Girdwood or Portage to the northern end of the Turnagain Arm Trail and arrange to have the TAS pick you up in Bird or Indian.
In Girdwood you might want to ride the Alyeska Ski Resort high speed tram to an elevation of 2025 feet. It costs $20. If you hike to the top terminal the tram is free back down.