Been to bend a couple of times. Going back in a couple of weeks on our way back from California. Going to ride Levi's Gran Fondo in Santa Rosa.
In Bend if you are limited to 1/2 a day, I'd go to Pine Mountain Bike shop. It's located in the same building as Cog Wild if you want to do a guided tour. Pine Mountain rents out bikes and is close to the Phil's trail system.
http://www.pinemountainsports.com/re...ummer-rentals/
this year we are doing the ale trail
http://www.visitbend.com/Bend_Oregon...end-Ale-Trail/