Stolen from MC-Chassis-design email list - practical example of\nreducing unsprung mass - 4 seconds a lap !!\n\n"This is lifted from the Burge racing website - the brothers who have\nbeen\nrunning Norman Hossack's original Yamaha chassis (number 3?) for the\nlast\nfew seasons\n\n[URL]http://www.members.aol.com/arcticla/index.html[/URL]\n"I rebuilt my Harris Rotax for the 2004 ACU Supermono Series, fitting\nnew\nexhausts and generally tidying and rationalising a few bits and pieces.\n\nI had some problems at the first rounds at Pembrey, where I crashed out\nof\nthe second race. Otherwise I've finished every race and had a great\nseason.\n\nI've been pondering the whole Supermono v Minimono question for a long\ntime\nand considering whether, because the current minimum weight limit of\n95kg,\nthere's a middle way? So, by way of experiment I decided to run GP125\nsized\nwheels on my Harris to see what would happen.\n\nBig investment? Not really. I was able to take the 3.5" rim off my\nfront\nAstralite and mate it to the existing rear hub. Then I dusted off the\ncomplete TZR front end from my 250 single racer, together with it's\nlighter\nforks and single 300mm disk.\n\n\nThe result? An instant 4s reduction in lap times at Castle Combe and\nCadwell!! Who says performance costs money?! The bike was very light\nsteering and nimble and I could run and turn into corners sooo much\nlater.\nThe reduction in weight and reciprocating mass made a big difference to\n\nacceleration and braking too. I moved up from 8th to 4th in the\nair-cooled\nseries in those two meetings and now seem to be running with a whole\ndifferent group of people. I'd say that was a successful experiment and\na\ngreat way of making a 14 year old bike competitive. "