when learning to play piano you look down at the keys,
but eventually you dont need to use visual cues..
on a motorcycle, you must maintain attention forward
with primary vision, which may be extended as you become
familiar with riding to include consciously expanding your
peripheral vision to take in more of the front/side view,
together with glancing thru rear view mirrors now and then..
when learning, and thinking of revs and speed, do it on a closed
course or quiet area without traffic and no distractions if possible..
otherwise, generally ride without thinking of the tacho or speedo,
as if they dont exist.. you dont want to develop a bad habit of
drawing your attention and thus mind from the road to instruments..
just as you will learn naturally to ride without having to look down at
the clutch lever as you use it, or the throttle as you apply it,
or the gear lever as you change gears, or the brakes, etc,
so you will learn to maintain your vision ahead in the direction
you are heading and intend to head [such as when cornering]
while still being able to take in momentary glimpses of
tacho [without dropping your head!] and also mirrors..
your brain and body will, learn this and these sequences,,
just as you could learn to juggle or play piano or whatever,
thru intent together with regular rational practice...
riders riding together often ride with different riding styles
incl speed at gear change and so on, while still riding
together as a loosly structured group of riders..
so it doesnt really matter,, exactly what revs
or speed you change at..
over time this will become natural and you will
probably smile when you think back at
how you were concerned about it
its not a bus its a motorcycle..
respect it,, but get out and
ride the thing...