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You must of had the red lights flashing in 6th?> Ive only ever seen 124mph, I recon 118 ish real speed.
 

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Discussion Starter #3
On an IAM skills day at Thruxton yesterday.
Can't recommend it highly enough. Six briefings, each one followed by 20 minutes on track 4:1. About 140 miles in total. Concentrating on hitting entry, apex and exit points (cones). Doing that smoothed out the ride and was faster. Scraped alot off the o/s of my boots (especially the right one). Managed to hang with the fastest guy on a BMW sports and we left the Fire Blade behind.
Only my third time on track so felt quite good.
Achieved 127mph on way to petrol station (weird but true) as only had 15 minutes to next briefing.
 

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"Achieved 127mph on way to petrol station (weird but true) as only had 15 minutes to next briefing."
That´s the spirit!
 

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Assuming the speedo is the usual 5-10% optimistic like all such devices that would put the real speed somewhere between 115 and 120mph. That ties up with the widely reported “estimated” top speed of 120mph.
 

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If you want an accurate figure then mark the tyre @ 6 o’clock and the road, put it in top gear and turn the engine one whole turn (360). Mark the road at 6 and measure the distance traveled in feet. Multiply that by revs achieved. Divide that by 5280 to get mph.
You’ll need to figure a way to turn the engine or mark the crank and push the bike.
Depends how much you really need to know.
 

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Discussion Starter #7
Thanks Hui.
Don't suppose one turn of wheel = one turn of engine in top?
What would you have to take off to mark the crank?
 

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Thanks Hui.
Don't suppose one turn of wheel = one turn of engine in top?
What would you have to take off to mark the crank?
Doubt it, but one way to find out.
The centre of the left casing has a removable plug to allow a special engine turning tool. If you remove this and mark the crank with tipex, push the bike any direction in top gear. If you want to make it really easy to push then remove the spark plugs.
The spark plug hole could be used also by inserting a chopstick or similar in the plug hole and going from tdc to
Don’t use a calculation based on the known circumference of the tyre size as this doesn’t account for the flex/bulge at the bottom which changes the diameter.
 

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Theoretical; 114,6mph @ 8000rpm using the front tyre size or 118 using the rear.
If you want accurate then charts and graphs won’t do it.
Even doing it the way I suggested is only accurate for that particular tyre wear, temp., pressure and weight.
 

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There is a direct connection betwen the engine at 8.000 rpm, the transmission (0,92 in gear six), the chain (15 to 46 teeth) and the rear wheel (1,979 m for one turn). It cannot be more accurate, it's just mathematics.
 

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There is a direct connection betwen the engine at 8.000 rpm, the transmission (0,92 in gear six), the chain (15 to 46 teeth) and the rear wheel (1,979 m for one turn).

It cannot be more accurate, it's just mathematics.
Ma hole.
It can and is more accurate if you ditch the mathematics, I can do the mathematics while having a shower but that does not take into account tyre manufactures differences etc. etc.
The difference between a brand new tyre and a well worn one. The amount of sidewall flex due to hard and soft compounds or pressures which changes the diameter and therefor the rolling circumference. The list goes on. Do you think the discrepancy of the speedometer is just sloppiness?? No, it’s because they cannot account for all the variables.

I was giving a way for any individual with any vehicle to workout a very accurate way of checking speed at any engine revs. if they felt like doing it.
Another way would be to go though a police speed trap flat out and the copper should be able to tell you how fast you can achieve. Probably in writing too.

Heavy vehicles have to be limited and calibrated to 56mph. In a previous life we would calibrate certain vehicles with worn tyres before fitting a new set. That vehicles were faster than others and could creep past them on a long steady motorway as I’m sure we’ve all witnessed.
 

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There is a direct connection betwen the engine at 8.000 rpm, the transmission (0,92 in gear six), the chain (15 to 46 teeth) and the rear wheel (1,979 m for one turn). It cannot be more accurate, it's just mathematics.
Rear tyre diameter will vary depending on temperature.
 

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Do you think the discrepancy of the speedometer is just sloppiness?? No, it’s because they cannot account for all the variables.
Not at all. Variable play some part but speedos always read fast it is a deliberate policy by manufacturers so that they cannot be sued when drivers/riders get speeding tickets. No law enforcement official in the world is concerned if a speedo reads slightly fast but it would bankrupt some manufacturers if in the USA people were found to be getting speeding tickets because their speedos read slow and a class action was taken out.
 

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Old school by hand or mathematically under the shower, here is the real result with red light on an running at the limiter:



Just 180 km/h resp. 112 mph.
 

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Wow I´m amazed. Are you on std. gearing?
And did you see in top, what revs is it was pulling when the red light goes solid? Apparently that´s adjustable
 

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Yes, everything standard and with a new rear tyre.

The dashboard showed 8.000 rpm (as far as it is able).

Where can I adjust this?
 

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Unfortunately you can´t, but your dealer can. While the bikes are new and in the running -in phase the rev light is set low, the dealer can then move it after the first service. Some do some don´t. Mine is somewhere north of 9000. But its very difficult to read .
 

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I found reading through this thread all very entertaining. Thank you. But what I don't get is why the top speed of a Ducati Scrambler is so important. To me 140 km/h is plenty fast enough on this bike. If you want to go much faster, why don't you just buy a Panigale of any model? They were built for going fast.
 
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