Question about low RPM vs mid RPM

[lancevance]

First of all, sorry for a dumb question like this.
I've googled for a long time but I still can't figure out,
which range of RPM i should use.

I know that higher RPM will have better efficiency ,
but at which point, our CBR250R will have a break-even milliage? (low vs mid vs high RPM)

I usually ride at 3.5k RPM and shifts at 4.5K RPM.
is it too low revs, and will such revs damage the engine? (both short and long term)


Thank you!

Please forgive my poor english, non-native speaker (I am trying my best )

[Wynne G Oldman]

Just ride in the range that feels best for your riding style.

[Jme250RA]

I think 4000 to 4500 rpm is about the lowest I would shift. anything lower than that and you are beginning to lug the engine. I generally shift around 9000 rpm. My mileage has never been lower than 60 mpg.

[toofun]

almost same question.. may b this thread could help you..
Perfect Speed of Gear Shifting

[MotoMike]

Even for casual riding, I'll run the RPM's up to about 6000 before I shift, and typical steady cruising RPM's at 7000 in the higher gears. If I'm running it hard, then 9000 to 10000. I Hardly ever run this engine below 5500 RPM (unless it's idling), there is just not much power being made below 5500 RPM.

[GoRide]

Originally Posted by MotoMike

Even for casual riding, I'll run the RPM's up to about 6000 before I shift, and typical steady cruising RPM's at 7000 in the higher gears. If I'm running it hard, then 9000 to 10000. I Hardly ever run this engine below 5500 RPM (unless it's idling), there is just not much power being made below 5500 RPM.

Must be the lack of oxygen in the air at the altitude you live at "cruising" at 10000.... some us never rev'd it up so high so far

[MotoMike]

Originally Posted by GoRide

Must be the lack of oxygen in the air at the altitude you live at "cruising" at 10000.... some us never rev'd it up so high so far

Didn't say cruising at 10000 RPM...

Steady cruising speed of 60 MPH in 6th gear = 7000 RPM*

Top speed is 89 MPH @ 10,200 RPM*

*with 13T front sprocket

[shisoshin]

startup she goes to 2krpm dropping to 1.5krpm so 3.5k isnt that much,
so you should ride above 3.5 as a general low limit.. for suburban
riding staying above 3.5 to say 5.5 should be ok for power/torque
thus not stressing the engine..

if you want to go faster then say 5 to 7 should be ok..
by testing out these rev ranges you will get a feel for
how the engine seems to like to its revs in the gears..

in general, given that youre not flogging it unmercifully
in very high heat with old oil etc, it is a honda
and youre not likely to hurt it by using its potential..
so be more concerned for letting it go too low, in revs,
rather than too high.. dont worry too much..
firstly, enjoy your motorcycle

[lancevance]

Seems I've to ramp up revs, thanks guys!

[Aufitt]

A good thing is to look at a dyno chart, it doesnt make any torque till 6k, and start building any power till about 7-7500.
then ride by the bum dyno and you'll never look at the tacho again.