Originally Posted by boatpuller
Very insightful additional information. Kind of messes up the consensus we were getting for the 21" front wheel, but good to have nonetheless.
I still think the 21" wheel is a product of Motocross and most pure offroad bikes are sold as Motocross bikes. (Trials bikes could be the one exception.) The push for high performance Dual Sport bikes causes them to be compared to MX bikes and made as close to a MX race bike that can still be made street legal. Back in the late 60's and early 70's the "Dual Sport" bikes were "Scramblers" and the light two stroke bikes were "Enduros". The scramblers were all 19" wheeled.