[basjoos]

If the springs are too light (weak), the covers tend to flutter (vibrate) at higher speeds. Spring longevity isn’t a major problem, with the current strength spring, the cover will function even if one spring is missing. The main maintenance I do on the front covers is, every couple of months, to check that both springs are present and that the rollers spin freely, making sure that the spin isn’t due to the roller’s axle spinning in its mount. When I was driving the car full time, I typically would have to replace a missing spring perhaps once a year and replace a seized roller about every 9 months. Those corrosion resistant rollers from McMaster look like the way to go, they didn’t sell those when I designed the cover, but should last longer than the model currently on the car.