cool things with wheels, since 2006
Once read a test of it in a Swedish magazine. They loved the concept, but not its execution, because the not-perfectly-balanced disc made the poor rider's head shake violently at speeds over 40 mph.
Wow, good point!
I bought one!As Kim said, it worked in keeping the rain off, but it was noisy, vibrated, and caused some very odd gyroscopic effects when you turned your head (bikes didn't usually have mirrors then). I think I used it about twice.Tony
Apparently they work very well in Kart racing, and you can still buy them.http://www.demon-tweeks.co.uk/karting/helmet-visors-fitting-kits/demon-tweeks-turbo-visor