No normal motorcycle or scooter cover will hold up for very long while traveling because of the constant jostling from the wind but if you could find a heavy denim type canvas that would hold up. Another thing to consider is how to mount it.
One last thing, any type of material that touches paint and being jostled around by wind will cause paint to wear out considerably fast.
2015 Palomino Puma Unleashed 351-THSS 37' Toyhauler
2013 F-250 Lariat CCSB FX4 Kodiak Brown Metallic w/18k Superglide hitch and Air Lift rear air ride
"Just put that hammer down and give it hell" -Jerry Reed