The rear derailleur hits the spokes while on the big cog.
Also, is it possible to retrofit an old fashioned downtune friction shifter to work this derailleur. I don't like the new fangled combo brake-grifter-shifter or whatever they call it? I don't have a clue how to adjust it and I'm a prehistoric caveman sort of guy and all I know about are old bike parts. This bike frame has no fittings for downtube shifters, of course.
It's a new REI Novara Randonee touring bike that I got at the REI 20% off sale.