Biking between Melk and Krems

I can't vouch for the bike hire, but the OBB web site tells me the train legs are totally possible and can even be done without a change they use REX Trains (regional express)

Check out Nextbike:

http://www.nextbike.at/index.php?id=1385&L=en&type=0

Or this one:

http://wachau-regiothek.at/?lang=en

Train schedules from Vienna to Melk and Krems to Vienna can be found here:

http://www.oebb.at/en/index.jsp

Thank you Emily and Debbie. I think we'll be able to make it happen.

I've done it, but long ago. surely it's still possible! We rented the bikes from the train station in Melk, I imagine there are more options these days.