I’ve been getting a lot of questions about what rig to run. The best answer I can give you is that the route is ~80% road. That’s a LOT of road.
I’d suggest something with a compact or triple driveline and no less than 25mm tires. Personally, I’d probably run 28mm front and rear. Anything over 42mm may be overkill.
Your mileage may vary.
You can register here: http://norcalspringclassic-march24-redbutton.eventbrite.com/
Also, the start time & location will be posted up in a few days. The start is in San Francisco and there is loads of easy, free parking, close to the 101.