Benny steered me toward the $20 Walmart covers. I liked it much better than the $80 fancy schmancy cover I had. The fit on the Wally cover was pretty good, but had excess on the back, even with a tall windshield & a Triumph sissy bar. I would wind up the excess and wrap the excess bundle with a bungee for a nice tight windproof fit. For $20...
Thinkin' out load, I don't believe there are too many covers that can survive direct exposure to UV for more than a season and remain waterproof, but I could be wrong. Look what the sun does to plastic chairs. Scotchgard seems to help.
As Santa & the lottery people have not yet made allowances for my first growth two story Birds Eye Maple toy barn, I'm probably going to get another el-cheapo sun canopy one of these days to replace the one I had that couldn't survive a snow load. It did have that Christo look all up on it flappin' upside down in the wind all Winter though. My wife didn't share that viewpoint. She renamed it "Whenerugoyng2takethatthingdown?" How could I take it down when one of the neighbors thought it to be a rain water collection device?