This is an idea that I had while skating across China in 2008 for fenders which would attach to longboard trucks/wheels to stop water and road grime from flicking up onto the board. My concept was that the fenders would be made from plastic, and attach on the inside of the wheel. I did this sketch on the 23rd of August 2008.
To my joy, it looks like someone (Chase Kaczmarek) had a similar idea and has taken it from an idea to a prototype product: http://longboardism.com/2012/07/wheel-shields-avoid-wheel-bites-and-skate-in-the-rain.html. Brilliant. He calls them ‘Wheel Shields‘ and it looks as though the main design intention was a device to shield against wheel-bite (the wheels touching the board when in motion and turning, causing the rider to be thrown from the board), with ‘fender’ functionality as an added bonus. The device is patented.
A huge thanks to Longboardism.com for the scoop on this one! Head over to the Longboardism.com post (http://longboardism.com/2012/07/wheel-shields-avoid-wheel-bites-and-skate-in-the-rain.html) and fill out a quick survey regarding the devices, and let Chase know what you think. I have already, and I told him that it is a brilliant idea.
(The two Wheel Shield images above via Longboardism.com)