Gear choice around town?

[Gizzit]

Hi there,
As I've newly returned to biking after a 35 year lay off ..... and Im on a bigger bike than I previously owned, I am a little unsure about how to treat my GSXF750 around town ... i.e. in a 50K zone. I have been trying to stay in the speed limit, and usually sitting in 4th gear, pulling a few revs, rather than getting into 6th and chancing labouring the motor.

Anyone got any ideas for or against gear choice with view to best economy and caring for the engine on a GSXF750 .... in 50K zones ?

Also what kind of gas mileage should I be getting around town on this bike with just normal riding .... i.e. not thrashing it .... just commuting to work and back?

Cheers,
Grant.

[merv]

If its geared about the same as my VFR at 50 you'll need 3rd, if you sneek over the limit when the plods are looking you might get into 4th. Anything higher in the gears than that you will be labouring the engine which is plainly not called for and don't shift into 6th until you're doing at least 90. Fuel economy if its as good as the Honda if you treat it nicely will be close to 20km/litre on easy running maybe as low as 16 around town.

[Gizzit]

If its geared about the same as my VFR at 50 you'll need 3rd, if you sneek over the limit when the plods are looking you might get into 4th. Anything higher in the gears than that you will be labouring the engine which is plainly not called for and don't shift into 6th until you're doing at least 90. Fuel economy if its as good as the Honda if you treat it nicely will be close to 20km/litre on easy running maybe as low as 16 around town.

Hi Merv,
Thanks for that. Do you know what kind of revs you are pulling in 3rd @ 50Kph ? I think I'm doing something around 3000 - 3500 in 4th ?

[merv]

About 3,500 in 3rd at 50. Just under 3,000 in 4th at 50 and I wouldn't normally let my engine run much under 4,000 so unless I'm doing more than 65 wouldn't have it in 4th. Your gear ratios could be a bit different of course.

[Black Bandit]

Labouring the engine? Wazzat?:scratch:

What are the side affects? Why is it bad?

[xwhatsit]

Labouring the engine? Wazzat?:scratch:

What are the side affects? Why is it bad?

<hints id="hah_hints"></hints>Some people call it `lugging' the engine. It's just when the revs are too low for the engine to be very happy; I don't know about bigger bikes, but on my little 250 if I use too much throttle with too low revs, the engine vibrates a lot, doesn't produce smooth power, seems very loud -- occasionally there's even a knocking sound, which might be my barrel needing an bore and oversized piston, but you can tell it's stressing the engine. It should be very obvious when it occurs.

Somebody told me -- now this might be complete bollocks -- that when you open the throttle too much at low rpm under load, that because the piston is finding it hard to go up and down and there's little momentum, it puts a lot of side-to-side movement in the piston, pressing it against the piston walls. No idea if this is true or not, it sounds plausible, but I'm far from being experienced with the whirly bits that go around and around beneath my knees.

[Guided_monkey]

There's a further problem with labouring the engine. As the rpm's are low the oil pump isn't delivering at full pressure. The engine under load then causes the oil in the big end bearing's to be squeezed out and you get excessive wear.

Try a higher gear.

When riding at 'low' speeds I'm normally in 2nd/3rd.

[MotoGirl]

I often ride a 600 Bandit (similar sort of machine to your's) and I tend to sit in 3rd when travelling between 50 and 60kph.
On my own bike (twin) I'm generally in 2nd, maybe 3rd depending on how fast the traffic is flowing.

[Pwalo]

FWIW I'd concur with using third rather than fourth. Not so much too avoid 'lugging' the engine, but more to ensure that you have immediate acceleration on hand.

On the SV I'm usually in third with about 4K revs. I'm sure that the GSXF is a bit more forgiving if you're running lower revs.

[Chrislost]

so about 8000RPM in 2nd?
on my vfr thats just fastenogh for the plods to want to take your licence, and just enough revs so a twist of the wrist means they cant.

[TKDSKIP]

I'm only new so dont bite if I'm wrong but..... I would have thought that talk of "what gear do you ride in" is not relevant unless we all ride the same bike. RPM is better, as on many bikes anything less than 3500-4000 would be starting to labour the engine. The bonus of keeping the revs higher than this is that if you need to gas it to get out of the way you can.

Just my thoughts.

[Gizzit]

About 3,500 in 3rd at 50. Just under 3,000 in 4th at 50 and I wouldn't normally let my engine run much under 4,000 so unless I'm doing more than 65 wouldn't have it in 4th. Your gear ratios could be a bit different of course.

Yes Merv I think that is about right. I noticed going to work and back today that in 3rd at about 3500rpm I'm doing 50kmh, and about 3000rpm to do 50kmh in 4th. The bike sounds better probably in 3rd, so will use it that way. I don't want to stress the motor! I just thought I would be using a heap of petrol that way.Thanks for the input.
Cheers,
Grant.

[Gizzit]

I often ride a 600 Bandit (similar sort of machine to your's) and I tend to sit in 3rd when travelling between 50 and 60kph.
On my own bike (twin) I'm generally in 2nd, maybe 3rd depending on how fast the traffic is flowing.

Yes I think that our bikes (Bandit 600 / GSXF750) would run pretty much the same (very similar engine), and I think I will now run around town in 3rd and at about 3500rpm, it's doing 50kmh .... but yes ... just more about going with the flow of traffic .... and if some nice tin top wants to do 60 - 70 kmh in front of you .... well why not stick behind them for as far as you want !! :innocent: :yes:
Cheers,
Grant.

[Gizzit]

There's a further problem with labouring the engine. As the rpm's are low the oil pump isn't delivering at full pressure. The engine under load then causes the oil in the big end bearing's to be squeezed out and you get excessive wear.

Try a higher gear.

When riding at 'low' speeds I'm normally in 2nd/3rd.

Yes I agree, and that was my concern about the revs at 50kmh. I will use 3rd gear from now on. It may suck through a bit more gas, but the engine will be better for it.
Cheers,
Grant.

[Gizzit]

I'm only new so dont bite if I'm wrong but..... I would have thought that talk of "what gear do you ride in" is not relevant unless we all ride the same bike. RPM is better, as on many bikes anything less than 3500-4000 would be starting to labour the engine. The bonus of keeping the revs higher than this is that if you need to gas it to get out of the way you can.

Just my thoughts.

Yes I agree with your comment regarding the bike, No "Bites" from me :) but yes ... thats why I stated what I was riding, so that anyone who has a GSXF750 (or a similar size/type of bike) may have an opinion about whats best for these 750's around town.

I came from riding a much smaller bike, .... and a long time ago .... so was just looking for general kind of views, from mainly other GSXF750 riders.

I agree with you about being in a lower gear to provide instant "get away" if you need to move quickly. It's nice having instant power!! 3500rpm in 3rd @ 50kmh works out pretty well for me. It feels a bit better to have it reving in that range, rather than 3000rpm in 4th, which can then more easily "chug", and I get instant grunt from that gear and rpm.
Cheers,
Grant.

[merv]

Remember fuel efficiency is all about the engine running in its sweet spot when the tuning of the engine is in harmony with the revs its doing due to valve timing and stuff like that. Run it at too low a revs and its probably spitting a lot of unburnt fuel down the exhaust pipe because of valve overlap. You'll know when you ride it right it will just feel right and not make any strained noises and the throttle response will be perfect.

[Gizzit]

Thanks Merv,
Yes it's just me getting to know the feel and sound of the bike, ... but I think I have got it more sorted. Sitting in 3rd at 3500rpm gives me 50kmh, and it sounds and feels good there, and is certainly very responsive to any slight throttle change. Im enjoying this bike more and more, and am looking forward to the weekend and hopefully some fine weather, to get a few more K's on some twisty bits!
Cheers,
Grant.

[babyblade250rr]

hiya,

i've just brought a cbr250rr and an new to riding also i think i may have been overloading my engine with low revs in the wrong gear also my question is it better to have the revs sitting higher in a gear with perhaps using more fuel than usual or say using 4th gear at 50km/h

cheers

[ambler]

Interesting. Every bike I have ridden was perfectly comfortable in top gear at 50kmh, never felt the need to use a lower gear for around town...

[Gizzit]

Interesting. Every bike I have ridden was perfectly comfortable in top gear at 50kmh, never felt the need to use a lower gear for around town...

I could run around town in 6th if it was flat with no tin tops in the way, but it means my bike is really low in revs. I was using 4th, but now using 3rd in traffic and pulling 3500rpm, and may even get back into 4th if its a bit quicker, and also in 70kmh zones .... 4th is fine.
Depends on the bike I guess. I have read write ups on the FJ1200 for instance that says that they can run down to around 30 - 40kmh in top, and pull strongly back up again .... as can the latest Bandit 1250. I still wouldn't use my bike like that around town, but in 70kmh zones and open road .... I would pretty much leave it in top on either of those big bikes.

[675trippy]

certainly agree with not labouring engine with low revs particularly because of oil flow in top end. most injected bikes have the ability to maximize fuel efficiency with standard mapping so that isn't much of a problem (with injected models). i have also heard of the side push of pistons while labouring but as long as you don't try to go to terminal velocity from low revs, you would definitely want to chop down a couple of cogs before contemplating that.

[delusionz]

No vehicle should ever be driven in 6th at 50 no way jose.
I cant comment on your bike but on mine best results are achieved with...

1st to 2nd @ 20km/h
2nd to 3rd @ 60km/h
3rd to 4th @ 80km/h
4th to 5th @ 105km/h
I don't use 6th.

[delusionz]

hiya,

i've just brought a cbr250rr and an new to riding also i think i may have been overloading my engine with low revs in the wrong gear also my question is it better to have the revs sitting higher in a gear with perhaps using more fuel than usual or say using 4th gear at 50km/h

cheers

I rode a CBR250R Hurricane before and it didn't make any power until at least 8,000RPM so I used around 9,000 - 12,000 for driving ofcourse this is a high revving bike (18,000 redline) so its designed like that. On my bike it makes power at 5,000RPM so I use 6,000 - 8,000 for driving with redline being 13,000.

In most cars with a 7,000 redline you would drive at around 3,000 - 4,000 RPM.

Notice how its almost always around the middle? It's very proportional...

This is what happens when you're Laboring, Lugging, Chugging (Gears up, Revs down) the engine - The combustion in your cylinders is not powerful enough to blast the piston down completely thus wearing out your pistons & connecting rods because your engine wants to rev (power of the blast) and your piston wont let it (wheels not moving fast enough, not enough momentum, ie - an opposing force to the blast).