I find the Barbur (99W) is bikable anytime I've tried it as I find car traffic is on the light side vs other routes. And it does have a bike lane most of the way.

Or you can take Max to Beaverton Transit or Beaverton Central and take Hall Blvd into Tigard. Then you'd have to take side streets to the 217/I-5 area. There is a bike path in that area that may help, it's near I-5 off of 72nd.