ShawnMC...I have to disagree with you about the 'Road Racer GP' bikes...and I have to disagree about the separate chambers for oil and for tranny fluid fight going on here. First, the GP bike statement. IF you are referring to the 125, 250 and 500cc (and this year’s ‘open’ 5-cylinder GP) bikes, they run comparatively similar engines to a ‘normal’ 2-stroke dirtbike engine..except they have more cylinders, obviously. They are running a single chamber filled with motor oil and either a wet clutch or a dry clutch. Most run a wet clutch setup, but there are a couple of teams that are running a dry clutch setup..but it is hardly “All of them”. Where the ‘dry clutch’ craze got started was with Carl Fogarty and the illustrious Ducati 996, 996R and 996SP/SPS race bikes. The V-twin 1-liter Ducati’s were making so much torque that the oils of the day (we’re talking late 80’s to early 90’s here… were having a hard time bridging the span between oil viscosity for the tranny and ‘top end’ and grip for the clutch. So they went to a dry clutch so they could dedicate all of the oil’s properties to giving the engine longer life (the rear cylinder of a V-twin takes allot of heat abuse…one way to help it out is to oil the hell out of it). As far as the dual-oil-chambered engines discussion…Yes, there are benefits to having a certain type of oil lubricating your top end and your crank bearings…and having another type lubricating your clutch. But with engines the size that we need them (they HAVE to fit on the bike) the benefits of being able to choose specific oils to address each area’s needs are VASTLY overshadowed by the fact that using smaller amounts of oil in each of the areas reduces the lifespan of the entire engine. I feel it is better to have one larger cavity filled with an oil that fills multiple jobs well, than to have two cavities that are filled with liquids that each do one job extremely well, but limit the life of the parts that the liquids were meant to protect. Even with ‘proper’ maintenance intervals (how many of us know what the SERVICE MANUAL says about how often to change our oil?) two chambers limits the life of the engine-side and the tranny-side. 'The Hopper'