I am currently riding a Honda CBX250 twister, doing mostly commuting on the highway, 50km one way. However I want to start doing longer trips, 300km an onwards and do some offroad riding perhaps do the GS challenge etc. I can JUST JUST afford the new twin F650, and then it still needs a engine cover bash guard and a larger screen, so the new 800gs will probarly be a better buy, however then it's out of my price range, so thinking buy the twin 650 and do the mods over time. However the old single 650 are quite cheap at the moment with lots of bargains. What mileage can the old single handle before one would need to open the engine? Would it be ok..for two up riding on say a 400km trip? Will it do 140/150km/h easily? Starting to think it might be a better buy, but I need to know if it will last me two to three years, before I upgrade to a bigger bike.