Rent a bike in Frankfort?

[barko1]

I'm taking a one week tour of Universities in Germany and was thinking of adding an extra day, maybe two, to tour a bit via moto. I start my official business in Berlin and end in Frankfor and wondered what are the chances of finding a bike to rent, borrow, or steal to check out the countryside?? Lend me a bike and I'll return the favor when you come visit New Mexico