Hi,

I got two bikes with real low end Shimano derailleurs, stuff you can't buy even
if you wanted to. The cheapest one works but needs a little overshifting going
down the gears, on the folder, the long cabling doesn't help. The next step up
fitted to the road bike works perfectly well, I've no issues with it at all.

The Tourney being better still should be fine, and simply do the job well.

rgds, sreten.