High gear, low speed, low revs, when is low too low..?

The title is a little vague I admit.
So... I'm travelling along a road at 30mph, but in fourth, and the revs are about 2k.
Idle is just over 1k on the beemer.

Would riding like this have a negative effect on the engine, ie it cant breathe enough at that speed, or have I made a mountain of a mole hill..?

Its more out of interest than concern.

Ta

[yorkie_chris]

Too few revs is when it starts farting about and slapping and such. What bike is it? The old K100 bricks etc seem perfectly happy to plod along at 1k.

I often bimble along at 2500-3000rpm in top gear,just under 60mph,which is about 1/3 throttle 9600rpm max. Keeping it where you can pull away without the engine labouring should be fine.In lower gears I can let it drop to 2000rpm but prefer to downshift to accelerate rather than strain the engine

Aye its the flying brick, K100, it happily plods along at 20mph in 5th, just wondered if it was fine.

[embee]

I don't know anything specific to the K100, but in general terms...

Bear in mind oil pressure doesn't usually reach the relief valve setting when hot until 2-3k rpm typically in automotive petrol engines, lower speeds when cold. So if it's hot I wouldn't run it down too slow under a lot of load, having said that 2k isn't particularly slow and most engines will be fine at that speed.

The other thing is that thermal efficiency tends to drop quite dramatically as you go below 2k in a typical petrol engine, and generally there's little if any fuel economy benefit in running it slower than this, so you may as well drop a gear.

As a rule of thumb, most engines will give the least service trouble when running in the middle third of the speed range, high and low speeds both bring their own issues. Car engines used on motorways will generally last forever.

I can't remember hearing the brick being delicate at all, so I'd bet on it surviving most things you could throw at it.

My FZ1 seems to love doing 30mph in 6th and pulls away as if it were in 3rd gear.




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