A couple of newbie questions about RPM

[Kiwi.in.transit]

So, I want to be nice to my bike... I really do. But, the problem is I'm a little short on knowledge at the moment. I'm riding a cbr250rr. Does it hurt her to constantly cruise at low revs... or high revs? What's the ideal? Or does it not really matter? I know she likes to warm up first... Also, what should she be idling at? I'm on the slow road of learning... please don't shoot me thanks!

[Quailboy]

Nice bike!

I believe idle is supposed to be 1500 +/-100 rpm.

[firefighter]

don't labour the engine ie. if the engine is sounding like it's in too high a gear it's bad, high revs are better, those little engines don't like being laboured.

[wbks]

1500rpm +/-100 like quail boy said and when you're cruizing through town it doesn't hurt to ride around in low revs so long as it doesn't bog under throttle which you will find out about as you ride in say 6th gear at like 5thouRPM. As for high revs unless you are over around 8-9000 revs while at low speed around the town it won't do any harm.I do 6-7thou around town so it picks up easy but doesn't labor the engine like firefighter said. What revs does your cbr sit at in top gear at 100km/h?

[sharky]

Remember to fully warm her up before you set the idle too ;-)
These things love to rev high, hence redline is at 16000rpm or whatever it is.

[Quailboy]

What revs does your cbr sit at in top gear at 100km/h?

At 100km/h they are 9000rpm if I remember correctly.

Also if you were at low revs and you had to accelerate out of a situation quickly you wouldn't get any engine response, instead you'd have to waste valuble time in changing down gears to get any boogie.

And cages will notice you more especially in traffic if you can sit a higher revs as the bike will be louder.

[wbks]

At 100km/h they are 9500rpm if I remember correctly.

Also if you were at low revs and you had to accelerate out of a situation quickly you wouldn't get any engine response, instead you'd have to waste valuble time in changing down gears to get any boogie.

And cages will notice you more especially in traffic if you can sit a higher revs as the bike will be louder.

This is true, just don't go riding around at 14,000rpm through town

[James Deuce]

And cages will notice you more especially in traffic if you can sit a higher revs as the bike will be louder.

I wouldn't even consider that as a "safety option". They can't see you and they can't hear you.

[discotex]

Higher RPM is better than low. Pretty sure I rode around 50km/h areas in 3rd/4th gear on my old ZXR250. 5th and 6th are really motorway/open road gears.

A good cruising spot is usually between 1/3 and 1/2 of the redline.

How to tell if you're bogging? When you open the throttle you don't get much pick up and the engine sound gets louder and fatter/lower. Kinda goes booohhhhhhggggggg instead of neowwwwwwwwwwww.

[steelestring]

They love reaching up into the high revs. Dont be afraid to hang 'around' the red line, this is where most of you power is hideing

[discotex]

They love reaching up into the high revs. Dont be afraid to hang 'around' the red line, this is where most of you power is hideing

There's power up there?

[stevewederell]

Careful of too lower revs. I believe me riding like a nana and changing up far too soon played a strong part in my plugs fouling (along with possibly wrong fuel) with the end result of her running like a box of arseholes!

I'm on a similar part of the learning curve too, KB crew bloody helpful tho!

[Ixion]

I am oldfashioned. As a general rule I like the old one of thirds

Keep the throttle between one third and two thirds open. Keep the revs between one third and two thirds of redline.

On a small buzz box, I would keep the revs a bit higher than that would indicate. Maybe half to three quarters.

None of that applies to two strokes. They are all sluts which must be mercilessly caned.

[GrayWolf]

Warming the bike up is not a bad thing, but the modern engine is far more user friendly when cold than days of yore.
Revs? regardless of where the bike makes max power, its simple engineering fact, the higher the revs, the higher the stress (piston speed) or wear and tear. These small bikes may 'thrive' on revs, the reality is the motors are relatively 'short lifespanned' in comparison to lower revving motors.
The best advice I think I can offer as a rule of thumb is; to be in the correct gear at low/moderate speed that allows you acceleration when required.
This does not mean sitting on the edge of the power band at 1 squillion RPM. There will be an area of revs where the bike is making power (torque) that is below the max power range. Probably around 1/3 of max rpm would be about right. Possibly slightly higher on a high revving small cc motor. Maybe best described as 3 stages of power, Boring (no power) Getting interested (Torque) and Yeeeeeha (Powerband).
If you are 'hovering' on the edge of the power band, (which is likely to be quite narrow) You will run out of available 'revs' quickly and need to 'change up' a gear ). This takes time and drops the RPM back down (the higher the gear, the slower the rate of acceleration). If you are in the gear that allows the motor to just enter into the rev range of the bike producing 'torque' it will be able to accelerate up into its powerband, leaving you in the accelerating gear for longer.

[CookMySock]

I wouldn't even consider that as a "safety option". They can't see you and they can't hear you.

On my noisy 650 vtwin I use its (standard) exhaust note and super-bright HID headlamps as safety options. No one dares pull out in front its nasty headlamp coz they cant see a fucking thing, and just pop it back a couple of gears and crackle, bang, pop, bang, boom, and the traffic parts in front of me like the red sea. Awesome! edit: skip the lecture coz I don't care.

Dont be afraid to hang 'around' the red line, this is where most of you power is hideing

That is not wise on any engine. It is fine to repeatedly redline a very well-maintained engine, but repeatedly lingering it there unloaded is race-bike territory, and with that comes race-bike maintainence schedules.

Really, you should be able to ride it around and do anything you like to it if its well maintained and run in properly. Just don't used sustained full-throttle for more than 30 seconds unless you have the RPM over halfway up the tacho.


Steve