The happy-motorcyclist, wind-in-your-face, bugs-in-your-teeth thing sounds great on paper, but by the time you can identify the particular species of insect parts in your toothbrush, a windshield starts to sound pretty swell. But whether it’s a see-through barn door sparing your face and eyes from flying debris or a stubby sport screen you crouch behind on a trackday, if you can’t see through it, a scratched or dirty windshield can be worse than no screen at all. Here’s how to avoid trading wind-in-your-face for crash-in-the-weeds.
Start with the right cleaning products. Never use any cleaner on acrylic or polycarbonate windshields that’s not designed specifically for the application. Common window-washing fluid works great on glass, but the alcohol or ammonia in it can damage the plastic and chew through the scratch-resistant hard-coating like a bulldog through a butcher’s shop. The milder the better is the rule here. If you can’t find an approved cleaner, mild soap and warm water will do. Often that’s what your owner’s manual will recommend anyway.
Your cleaning supplies should be squeaky clean right from the get-go. No paper towels—they can scratch the plastic—no shop rags, not even new ones, and for the love of all that’s good and holy never use that filthy squeegee in the tank full of pond water attached to the gas pump. Get a cleaning cloth made of terrycloth, cotton flannel, or microfiber, turn it often as you clean, and run it through the washing machine frequently. While it might not show up on a painted surface, the tiniest bit of dirt trapped in the cloth can ugly up your clear windshield with astonishing ease.
Park the bike in the shade so the windshield is cool before you start. The cleaner will work better—specifically, it’ll dry more slowly—and it’s easier to see scratches and dirt in soft light than in bright sunlight. Using plenty of clean water, rinse off as much dirt as you can as gently as you can; the biggest risk of scratching is when the windshield is dirtiest. Remove welded-on bug carcasses by laying a wet cloth or wet paper towel flat on the windshield. Give the water a while to loosen the worst of the goo then pull the towel off without wiping across the surface. Then get after what’s left with your fingernail. The more you remove this way the less pressure and cleaner you’ll need later and the less likely you’ll scratch the plastic.
Dry the windshield by dabbing the water with a clean towel and apply the cleaner according to the directions on the container. Use too much and you’ll make a gooey mess; use too little and you risk scratching the plastic. You don’t get extra points for finishing the job sooner, but you’re more likely to inflict some battle scars if you rush. It doesn’t matter much if you use a circular motion or up-and-down motion as long as you don’t press too hard. Pretend you’re rubbing the tummy of a sleeping alligator. Turn the cloth frequently so the side facing the windshield is always clean. Stop and pick out any big bits the cloth picks up.
The last step is applying a plastic protectant, essentially a see-through version of the wax you use on your paint. It does the same thing, too, by providing a layer of protection against future dirt accumulation and insect impacts. Most aerosol plastic cleaners like Plexus and Meguiar’s are also polishes and protectants. A note of warning about rain treatments: Just about every windshield manufacturer warns against using Rain-X, a popular treatment that makes water stream off car windshields in wet weather. Instead use a product such as RainZip from National Cycle.
You can remove existing scratches with products like Novus or Meguiar’s M17 Clear Plastic Cleaner (and M10 Clear Plastic Polish). Take it slow to avoid going too far too fast, and don’t use one that’s too gritty or you’ll cloud the area around the scratch. The large, milky-white areas that won’t polish out are typically caused by tiny internal cracks in the material itself—called crazing—caused by chemical contamination or stress resulting from improper mounting of the windshield. Small cracks can be temporarily stopped by drilling a tiny hole at each end, but by this time the structural strength of the material is compromised enough that you should replace the windshield.
Scratches in translucent plastic show up more readily than on painted parts. When you work on your bike and the job takes you anywhere near the windshield, cover it with a towel or an old T-shirt to help prevent scratching it. As an alternative, try painter’s tape to mask off parts of the plastic if you’re cleaning or polishing other surfaces nearby.