Many years ago , while speeding down a disturbingly narrow Welsh lane , probably about Roman chariot width - time moves slowly in Wales - motorcycling legend Tim Gibbes ( if you don ’ t know who Tim Gibbes was CLICK HERE to find out more ) was driving and he got to recounting a yarn about a factory BMW enduro racer of the late 1950s . The guy was racing a BMW ‘ boxer ’ with reduced flywheel weight and the balancer shaft removed . Tim said the bike was very fast , but vibrated extremely badly . Every time the guy changed gear while hard on the gas , he had to throw his body weight left to counter the violent leap it took to the right . Tim reckoned it jumped sideways almost a metre straight across the road and the marks on the gravel were something else - like a progressively lengthening series of Zs going up the road . A sight to behold no doubt . Tim was not the sort to waste words on the unimpressive . Anyway , all this came to mind recently while out on the new BMW F900GS . Mainly because it was an indication of just how far engines and power deliveries have come in the last , err , 60 or