Hi there, I am not from Austin but do travel there 3 to 4 times a year. Here are my 2c : for a great casual meal go to 24 Diner across the street from Whole Foods Downtown. Great eclectic food and good selection of wines and specialty beers. Perfect before a long ride AND after IMHO .
For a different ambiance for a meal try Buenos Aires on Bees Cave area near Barton Creek which brings us to where the fun places to ride start. Anywhere south should be fun (Hill Country). Places near by would be Fredericksburg and Enchanted Rock (German town and state park fun ride), about 1 hr north west. Blanco Texas has the best brewery around: Real Ale. Great to take a ride there and taste as well as Shinner Texas.
You need a ride, try : http://www.sportryderrentals.com/Mai...otorcycles.php
They are in Dallas (3hrs north of Austin) but they might have a solution. They also have great ride maps available (see the top bar on their website). I do know tht Harley dealerships rent bikes if you are into that type of bike. Anyway, Austin is cool. Get a sticker for your bike that reads: Keep Austin Weird. And don't miss the music scene and maybe some kayaking in downtown.