You can shift a car without a clutch too. On upshifts you let off the gas and pull the stick into neutral, wait for the rpms to drop to match the next gear, then apply a little pressure to the shifter into the next gear. If you do it right it pops into gear with no harshness. On downshifts you have to blip the throttle to bring the RPMs up. Again, just pullit out of gear, blip the gas then apply pressure on the shifter towards the next gear. You have to know how far apart the gears are in RPM when you're first starting out, but after time you just get used to it. 1-2 is about 1500rpm, 4-5 is only 500. Do I do this all the time? Heck no. It's a cute little party trick, but for regular driving I just use the clutch instead. I *DO* blip the throttle on downshifts while using the clutch, though, to reduce the rpm diff between the flywheel and clutch thereby reducing clutch wear. Same with the bike. I always use the clutch, and I blip the throttle to smooth out downshifts. I ride a cruiser, though, so I'm never anywhere near the performance limits of the bike. If you're pushing the envelope around the track on a sport bike then your shifting and weight transfer/balance characteristics are different than mine need to be.