If I read correctly before on this forum the clunk you get with first or reverse shift is due to square cut gears. If true what is the advantage or disadvantage?
Possibly... (just a little.

) but that clunk when first shifting from neutral into first or reverse is much more related to the nature of the 'constant mesh transmission' that BajaRon mentioned above & the clutch that's swimming around in there with all the gears! It's basically because
ALL the gears in the gearbox are turning whenever the engine is running, but the output gear on the output shaft
ISN'T unless you've selected a gear, which usually means first or reverse - so when you engage a spinning gear with the stationary gear, there's going to be some degree of a clunk, simply because the stationary gear has to match speeds with the spinning gear and due to the laws of physics, that can't happen without some reaction! :shocked:
To some degree, that 'clunk' is there on pretty much
every gearbox/clutch/output shaft relationship known to mankind, albeit usually damped somewhat - it's just that constant mesh motorcycle gearboxes are usually relatively lightweight & compact of necessity, so there's not much scope at all for adding the extra weight & complexity that dampening the clunk would entail. So it's an inherent part of the machine, and beyond the lightweight performance delivery advantages of a motorcycle over most other vehicles with gearboxes & clutches, there is no real disadvantage except that some people don't 'like' it....
It's the nature of the beast, it's not wearing or damaging anything, it adds to & probably even enhances the performance and the 'feel' of ryding a unique machine; so enjoy it, & don't fret over it!

hyea:
Ryde More, Worry Less! :yes: