Author Topic: Revs per km/hr (for rider safety and engine longevity)  (Read 2497 times)

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SteveThackery

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Reply #30 on: December 27, 2023, 11:07:53 am
A lot of the GT 535’s came from the factory with pre-detonation issues below 3,000 RPMs. 


There's no such thing as pre-detonation. You mean either pre-ignition (where the fuel-air charge ignites before the spark), or detonation (where some of the charge detonates instead of igniting after the spark has initiated the burn). In reality pre-ignition often involves abnormal combustion such as detonation, but it is still called pre-ignition.

Do a search on this forum for “Squash Modification”. 


I think you mean "squish".

In my opinion, your lugging the engine when ridding around below 3,000 RPM.


What is the basis for this opinion? Nobody can measure the stresses and strains in the engine components by placing their buttocks on the seat.

The 535 UCE engine is not designed for low RPM lugging around. 

I assume by "lugging" you mean large throttle openings at low rpm, such that the hydrodynamic lubrication between working surfaces breaks down, causing rapid wear. How do you know the engine is not designed for that? How do you know it happens below 3000rpm, and not 1000rpm or 4000rpm?  Bearing in mind the 535 is fundamentally identical to the 500 UCE, you'd think it would be much the same at handling "lugging". I don't think we have any idea of the conditions under which hydrodynamic lubrication breaks down in either variant of the engine.

I recall reading somewhere (I can't remember where, so this is probably worthless) that the UCE is designed to handle 40bhp.  If true, it is comfortably inside its operating envelope, even in 535cc guise, so even "lugging" it probably won't do much harm.
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GUNR

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Reply #31 on: December 27, 2023, 11:42:13 am
I assume by "lugging" you mean large throttle openings at low rpm, such that the hydrodynamic lubrication between working surfaces breaks down, causing rapid wear.
For me, not large but minimal throttle openings. What I know as 'lugging' is the feeling of an engine beneath me which feels lazy and that any 'awakening' from its slumber would cause undue effort on its part without changing into a lower gear.

Here in Australia we have a vast number of speed limits on some of the 'more entertaining' roads (25, 35, 45, 50, 60, 70, 80, 90, 100, 110kph) e.g. the winding Oxley Highway with its 300 corners.

Out of this plethora of limitations, 50kph is the only one which causes concern for me using the standard 18/36 gearing and on original size tyres.

50kph at 2,500 in 3rd on level ground on gentle throttle increments feels velvety smooth but any change in traffic conditions or if an incline appears, I immediately change down and 'awaken the beast within'; whereas 3,000 in 2nd at 50kph makes the engine 'surge'.

3rd, 4th & 5th have no problem sitting at 3,000 (or above) and feel wonderful!
« Last Edit: December 27, 2023, 11:46:47 am by GUNR »
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gizzo

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Reply #32 on: December 27, 2023, 12:03:36 pm



 

What is the basis for this opinion? Nobody can measure the stresses and strains in the engine components by placing their buttocks on the seat.




Because 'Murica. The land where opinion has replaced science or facts as accepted truth. The louder he shouts his opinion, the more right he is. Ask their [ex] Dear Leader.


IMO ( ;D )

For me, 50kph in 2nd is 3,000 and in 3rd it’s bang on 2,500. I’m running the standard 18/36 2:1 gearing; have you lowered your gearing?
nah. Stock gearing. Those are just the numbers that I tried remembering from my ride. I'd need to video the clocks to be 100% sure, and that's not happening.


[edited for less nastiness]
« Last Edit: December 27, 2023, 12:15:46 pm by gizzo »
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GUNR

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Reply #33 on: January 06, 2024, 07:06:18 am
Take away quotes from the link below...

"Never lug your engine...now go forth and rev the t*ts off your motorcycle".

"you paid for the whole tachometer, so use the whole tachometer"

https://www.youtube.com/watch?v=zhUI7MWE_Fc
Riding a motorcycle is like life; it's about the journey not the destination.