Powerbands and changing gear?

[KiWiP]

Bit of advise please

I'm getting thoroughly confused with the gearing on my new bike 2008 Suzuki GSX750F

How high can I rev it before It does damage? I am able to get through all 6 gears at 80ks . I know that the revs have got to be too low for this gear but if I'm in a lower gear I just 'feel' the revs are too high. This is despite the rev counter has buckets of space before the red line. I figure as I have no experience of an in line 4 I'm just being too precious with it.

I don't have the experience to go screaming about so I'm not looking for high performance figure, I just like to know when to change so I'm not laboring the engine

Thanks

[Spuds1234]

Change gears before the redline and your right as rain.

Also cruise in a gear that gives you plenty of instant acceleration (to get out of trouble if need be) and doesnt make the bike vibrate a whole bunch (like it would at the top of the rev range).

Letting the engine lug around in gear thats to high for the speed your doing will damage your engine.

[Taz]

You should have learnt all this on your sub 250 learner bike.

[schrodingers cat]

Letting the engine lug around in gear thats to high for the speed your doing will damage your engine.

Old wives tale. If the engine is 'knocking' when heavily loaded then yes. Otherwise the only thing that is happening is it will be using (wasting) more fuel

Force generated is called torque
Torque multiplied by RPM is horsepower/kilowatts/PS whatever

The closer you match your speed/gear selection to the peak of the torque curve, the better the engine response. Having said that the power specs are Power in 1992 was 96.4bhp@10750rpm, with torque of 52ft/lb's@9500rpm. so in reality most of the time you'll be riding on the upcurve of the torque curve.
Round town I seldom go above 3rd gear. Acceleration is good. Engine isn't revving unnecessarily

RPM is limited by max piston speed m/sec and the ability of the valve to follow the cam profile. The manufacturer puts a red line there as an indication. Due the the inherant vibration in all 4 cylinder engines often you'll FEEL that the engine is getting a hard time whereas what you are feeling is a harmonic in the engine. This is more apparent in lightweight engines as there is insufficient mass to damp the vibration.
As an aside, often the development engineers will play around to move the most obvious and annoying harmonics into a rev range that is seldom used.

So. Your FEELING is just that. A FEELING.

[ellipsis]

....what did you learn on ,a twin ....a four will rev a lot more than you are maybe used to feeling/hearing....if your tacho is working fine , believe it....rev it....

[Spuds1234]

Old wives tale. If the engine is 'knocking' when heavily loaded then yes. Otherwise the only thing that is happening is it will be using (wasting) more fuel

Force generated is called torque
Torque multiplied by RPM is horsepower/kilowatts/PS whatever

The closer you match your speed/gear selection to the peak of the torque curve, the better the engine response. Having said that the power specs are Power in 1992 was 96.4bhp@10750rpm, with torque of 52ft/lb's@9500rpm. so in reality most of the time you'll be riding on the upcurve of the torque curve.
Round town I seldom go above 3rd gear. Acceleration is good. Engine isn't revving unnecessarily

RPM is limited by max piston speed m/sec and the ability of the valve to follow the cam profile. The manufacturer puts a red line there as an indication. Due the the inherant vibration in all 4 cylinder engines often you'll FEEL that the engine is getting a hard time whereas what you are feeling is a harmonic in the engine. This is more apparent in lightweight engines as there is insufficient mass to damp the vibration.
As an aside, often the development engineers will play around to move the most obvious and annoying harmonics into a rev range that is seldom used.

So. Your FEELING is just that. A FEELING.

TIL something new.

[Gibbo89]

Bit of advise please

I'm getting thoroughly confused with the gearing on my new bike 2008 Suzuki GSX750F

How high can I rev it before It does damage? I am able to get through all 6 gears at 80ks . I know that the revs have got to be too low for this gear but if I'm in a lower gear I just 'feel' the revs are too high. This is despite the rev counter has buckets of space before the red line. I figure as I have no experience of an in line 4 I'm just being too precious with it.

I don't have the experience to go screaming about so I'm not looking for high performance figure, I just like to know when to change so I'm not laboring the engine

Thanks

i wouldn't drive around in 6th at like 50 or 60 k's, like mentioned above, you need some power at the twist of the wrist to manage certain situations. revving anywhere under the red line is not going to kill your engine.

i had the same thoughts when i first got my inline 4, i think when i drive at 50kph i am revving at around 4 to 5rpm in 5th, in 6th gear at the same speed the bike doesn't feel right, its sluggish as.

you will get the hang of the bike sooner than you think

[KiWiP]

You should have learnt all this on your sub 250 learner bike.

Quite right, that's what the learner and restricted time is for. But my L&R bike was not a sport but a single pot which was incredibly straight forward in terms of 'knowing' when and where to change. The 750 is a completely different kettle of spanners...

So. Your FEELING is just that. A FEELING.

Cool this is what I suspected, the redline at 12K did seem to suggest I could wring more than 3-4K out of it.

....what did you learn on ,a twin ....a four will rev a lot more than you are maybe used to feeling/hearing....if your tacho is working fine , believe it....rev it....

Well today I have braved up to 5-6K and noted that the Oomph! increases so must be going into the proper powerband territory. Still sounds weird compared to the 250 but then Orville Wright would have some thing to say behind the joystick of an F15 Fighter.

Thanks for your input guys

[schrodingers cat]

Well today I have braved up to 5-6K and noted that the Oomph! increases so must be going into the proper powerband territory. Still sounds weird compared to the 250 but then Orville Wright would have some thing to say behind the joystick of an F15 Fighter.

Thanks for your input guys

This might interest you. It is a dyno sheet for a GSXR 750 so close enough to your jigger. There is a hole is the torque curve around 3500 rpm and a bit of a dip at 5500rpm. And then it gets going!
Riding round town around 4000rpm will give OK response

[Dadpole]

A GSX750F is perfectly happy at below 3000 rpm in top gear. Just don't expect instant get-up-and-go. They are designed to produce good torque at low revs.

the beauty of a larger engine is the rev range where usable power is available. For instance, on my bike, I can go into a corner in top at below 2000 rpm and have plenty of acceleration coming out.

Just play around until you find the best engine speed to suit your riding style.

[jonbuoy]

Lugging a bike engine isn´t good for it long term, its hard on the bottom end and can cause carbon build up. Keep the engine spinning its what they are designed for. Heavily built car engines and diesels are designed for low revs and high loads, light little bike engines are designed for higher revs.

[marty]

you will be able to pootle around in top at 50km/h no sweat. it makes the bike so much smoother and economical. just don't expect to pull away quicky - you car wouldn't in 5th gear either. my big IL4 was quite happy at 30km/h in 6th, and would pull from there to ten times that speed without a gear change. as long as the revs don't drop below the idle speed, you'll be fine.