[mcorrell]

I double clutch on up and down shifts also. As others, I assume it is SOP for non-synchronized transmissions. I am not sure how it compares with others, but on upshifts I clutch, shift into "N", clutch and shift into higher gear (all at no throttle). This seems to work well with little or no grinding regardless of speed. Downshifting is similar but I try to match engine rpm with ground speed.