Well today I was pulling apart a mini bike engine and noticed that it too, along with some other motorcycles runs roller bearings on the piston pin, rod journal and for the mains (which were only 2). It makes me wonder why they do not try and evolve this technology to work for passenger cars or race applications, either way they would improve mpg, increase efficiency and increase power. Just think about the technology that has evolved recently and how much it could benefit us. Picture a car with direct injection, solenoid valves(intake and exhaust), and roller bearings on everything vs friction bearings. I believe the 7 series bmw is the only one running the solenoid valves as of yet. I know F1 does something similar but uses pneumatic valves, which is the same idea. It would be interesting how much power something like this would free up. Plus think about the solenoid valves, one could run endless camshaft profiles and idle like stock.