The instructions on the ad and those with the fenders were very incomplete. What they don't tell you is that you have to remove each wheel to be able to remove the bolts, place the valve and bolt it back in to hold it in place. Even with a "short" screwdriver, the wheel prevented access to the screws. Unless you have a complete "tire change station" expect A LOT of work installing these flaps. Now I just have to wait for bad weather to see how they do.