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Old Apr 29, 2012 | 09:59 AM
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Originally Posted by grbrown
mph=3,000*60*25.2*3.14159/1760/36/2.79
Pretty Sharp!

80.61264662756598
 
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Old Apr 29, 2012 | 10:02 AM
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Originally Posted by TickTock
Pretty Sharp!

80.61264662756598
Thanks! We've got there! No point making things easy.....
 
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Old Apr 29, 2012 | 10:06 AM
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To verify that just get on the scoot & ride for an hour at that rpm in 6th & see how far you get. Let us know how it does.

Toby
 
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Old Apr 29, 2012 | 10:11 AM
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I rode about 400 miles at 3000 rpm in 6th gear, and my speedometer indicated I was doing 80, but my GPS said I was only doing 77-78mph. Rainy day on I-95, don't know if there was a head, tail or side wind, I was more worried about 18 wheelers.\\
 
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Old Apr 29, 2012 | 10:21 AM
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Originally Posted by grbrown
Come on old chap, you're British as well! Read my reply above! It's all there.....
Saw that, but only saw a row of numbers, not confirmation of what each was, apart from the pi constant which is clear. Silly me :-)
 
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Old Apr 29, 2012 | 10:46 AM
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Originally Posted by sgdiesel
Saw that, but only saw a row of numbers, not confirmation of what each was, apart from the pi constant which is clear. Silly me :-)
I agree. That 2010 probably has a 68 tooth rear pully that makes the final drive ratio 2.968 not 2.790. And without knowing the tire may not be 25.2 in dia. My tire per Dunlop is 25.71 dia when new and these numbers put my calculation at 77.32 mph.

25.2" dia tire runs 75.78 mph.
 
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Old Apr 29, 2012 | 10:56 AM
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Originally Posted by Sandcrab
I rode about 400 miles at 3000 rpm in 6th gear, and my speedometer indicated I was doing 80, but my GPS said I was only doing 77-78mph. Rainy day on I-95, don't know if there was a head, tail or side wind, I was more worried about 18 wheelers.\\
Believe the GPS the error you see is what almost everyone sees on a touring Harley

And the wind won't affect the result unless it strong enough that your clutch or rear tire is slipping.
 
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Old Apr 29, 2012 | 10:56 AM
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Originally Posted by X Iron Butt
I agree. That 2010 probably has a 68 tooth rear pully that makes the final drive ratio 2.968 not 2.790. And without knowing the tire may not be 25.2 in dia. My tire per Dunlop is 25.71 dia when new and these numbers put my calculation at 77.32 mph.

25.2" dia tire runs 75.78 mph.
There's a man speaking a common language even though we are separated by a massive pond :-)
 
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Old Apr 29, 2012 | 10:59 AM
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Originally Posted by Texas Fat Boy
This may be a stupid answer but, why do you just drive it and see?
Good answer
 
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Old Apr 29, 2012 | 11:15 AM
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Originally Posted by TWIN CAM 96
Good answer
How is this a good answer he asked how fast he was going not what does the speedo say? Two different apples and different from bike to bike. I have a handheld GPS but wouldn't go buy one to check the speed of my bike.
 
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