when do you shift gears on a motorcyle for example a yamaha r6s

when ever u need/ want to..

l quite often take of quickly in first.. reving to almost red line..

then just click up the gears to top. speed limits usually passed by then anyway.. so have to slow down..

but where u change gears in the rev range is a mute point unless ur racing.. then u should change gears just after max power is reached.. which would depend on what bike ur on.. but its usually 1000 to 1500 RPM under red line.so on the R6.. about 14500/15000

if you are riding on the street, then you really have no reason to go above about 7k or 8k or so. smoothness is key

on the track, you can ride up to redline and ''bounce'' off the limiter to shift into the next gear without pulling in the clutch or rolling off the throttle, if you practice you can get it smooth, do not worry it wo not hurt the bike

Never over the red line on the tach and under 3000rpm. Usually arround 6-7K