Sorry, no suggestions. Start your rides later?

The same thing happens hiking early in the morning. If you're the first one down the trail early in the morning, you get a face full of spider silk. (And, it's covered in dew, so you get a double dose, spider silk and wetness.) Silk in the face during hiking is a different order of magnitude, of course, since walking is slower than riding. Fortunately, trails are usually wide enough that you're just getting the silk the spiders trail after them, and not the full web. So, usually just strands of silk and not the spiders themselves.