Humm that's not an easy one. Vancouver is a very busy city, tourism-wise.
Try the Holiday Inn on Broadway at Willow (or Heather, can't remember).
There are no hotels within the immediate vicinity of the race start but any downtown hotel near Granville street will be not bad because you can take the #4 trolley bus to get to the race start. There is also the YWCA. Check out the Best Western Chateau Granville too.
Good luck!