It's really slick, and I upshift this way about 75% of the time. You can do it at pretty much any RPM, but at lower RPMs in 1st and 2nd you can buck the bike if you aren't really smooth with the throttle. I've found it's easy to do smoothly at most any RPM in 3rd-5th gears. It's always smooth under hard acceleration at high RPM's... smoother than using your clutch.
Also, in theory it should work when down shifting, but the sudden drag on the tire could make you actually drag your rear tire, especially in lower gears depending on RPMs (2nd to 1st) - so I'd avoid it. Perhaps I know this because I've done it - although I was on good pavement so the tire only chirped.
The way it works on a downshift is you let off the gas to let the bike start to slow, then put downward pressure on your shifter, then roll on the throttle slightly and it'll down shift. It's not the smoothest, unless you are downshifting to accelerate - then it's quick. I have no idea if this is bad for the bike though. I just know it works with no grinding or anything. It's the same mechanical feeling as the clutchless upshfit.
Anybody else ever try this?
