Foam mousse instead of tire tubes? Today I was told by the service manager at the local Kawasaki dealer that I should consider using foam donuts instead of tubes in my tires for my Americas Motopaseo next year to eliminate flat tire problems. He said they come in different densities (soft-hard)for different conditions. Does anybody know if this is strictly a race item or is it a viable alternative worth consideration for adventure touring? If so, where do I get them? If they can be used, would the same density be used front and rear? I'm guessing my tour will be 80% highway and 20% other (gravel, dirt, mud or sand). Furthermore, would the use of foam donuts be a serious consideration when choosing which tires to use with them? I would think so. Give me some feedback.