Horsepower, weight and aerodynamics

Discussion in 'Australia' started by Adrian V, Oct 13, 2018.

  1. Adrian V

    Adrian V Long timer

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    Having just struggled up to an honest (gps) ton on my airhead, are there any handy rules of thumb out there to estimate bhp based on weight, type of bike, tyres etc?
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  2. tomrux

    tomrux Been here awhile

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    The correlation you are looking for is in the rate of change in velocity ie; acceleration. And yes there are forulae out there prolly phone apps if it has an accelerometer sense in it. I do t know if the gps update would get it but maybe.

    Cheers Tom R
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  3. Adrian V

    Adrian V Long timer

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    I thought ultimate hp determined top speed, weight and frontal area not withstanding?
    A bike might accelerate quickly, due to low gearing etc, but may not have a high top speed?
    Comparing like bikes, my bike is a dirt tourer say 180 kg + 32l fuel + a 105kg fat bastard, how fast would say a 690/701 go similarly encumbered, i.e can I estimate my hp?
    #3
  4. OldDog

    OldDog non impediti ratione cogitationis

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    Moroso slide rule and crack out a few et's
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  5. Dave Ward

    Dave Ward Long timer

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    What, no mention of turbos Bill?
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  6. OldDog

    OldDog non impediti ratione cogitationis

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    Weeeellllll....
    ...
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  7. Paul124ac

    Paul124ac Long timer

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  8. Mouse

    Mouse I'm only smelly

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    Having run around and around and thus conjured up an imaginary figure what ya gunna do with it Adrian? Wish you had 5 more?
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  9. Paul124ac

    Paul124ac Long timer

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    Wouldn’t be a petrol head unless you wanted more hp. Mind you a formula for calculating dollars spent to hp gained might be more helpful. I remember an interview with Victor Bray, he said he knows exactly how to be a millionaire in Motorsport. Start with 6 mill, race for 5 years.
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  10. Adrian V

    Adrian V Long timer

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    #10
  11. Adrian V

    Adrian V Long timer

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    Nope, just musing, I’m quite happy with the bike as it is :ricky.
    I do however find myself comparing it with other bikes I’ve had and the closest I can get is my old 640 Adventure, which had fully worked suspension and a steering damper, but this bike has a much nicer motor and feels better in the 100 - 130 range.
    Cheers,
    Adrian
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  12. Mouse

    Mouse I'm only smelly

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    Give me torque...
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  13. ferals5

    ferals5 Team black bikes

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    Hand in hand... to get more shetlands you need more torque :D
    Shetlands = torque x revs
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  14. Mouse

    Mouse I'm only smelly

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    Uh huh but only one of them does any work... afaik.
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  15. Boxa

    Boxa 2 Smoking Barrels

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  16. ferals5

    ferals5 Team black bikes

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    hp is how fast you can do the work :-)
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  17. darren70

    darren70 I don't own a KTM

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    I’ll share a philosophy that I live my life by when it comes to anything with a motor from a bike to a boat to a chainsaw.


    ‘If you’re not scared to hold it flat the motor isn’t powerful enough’
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  18. Adrian V

    Adrian V Long timer

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  19. Mouse

    Mouse I'm only smelly

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    It's what I really liked about the rune, only needed one gear being top gear. Eg I could ride galston gorge and never change out of top gear.

    Adrian, iirc adrenal also had some info and a calculator in his salt thread. Or maybe it was in godsilla's most recent lake thread.
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  20. numbat

    numbat Been here awhile

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    More horsepower is a very expensive way to go faster per dollar relative to a reduction in frontal area/improvement in aerodynamics.
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