UK Karting - Notice Board (2-Stroke Karting) : Re: Microsoft Excel!!!

Notice Board (2-Stroke Karting)

Re: Microsoft Excel!!!
Posted by 'Bod' on 01 Apr 2010 @ 01:07

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BodJoined: July 2009
Total Posts: 1
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people say how easy it is but don't explain. I'm a bit pi**ed but here you go.

The gear ratio is simply dividing the rear sprocket by the front sprocket. Eg 72 divided by 12 = 6. this means that ever 6 turns of the front sprocket = 1 turn of the rear wheels, i.e. 6 to 1.

to work out speed divide revs by ratio (giving rpm of wheels)
multiply by circumference of tyre, in inches (giving inches per minute)
multiply by 60 (number of minutes in one hour)
divide by 63360 (inches in one mile)
this equals speed in mph.

As I have said I am a bit drunk and I am also listening to Mozart at high volume so this might not make much sense and I may have made a mistake. Even when sober I am a crap teacher because I struggle to understand what's obvious to me, is not to others. So here is an example.

14 front, 75 rear. Tyre diameter 37 inches. Revs 9000
75 divided by 14 = 53571428.(5.36-1)
9000(revs) divided by 5.3571428(ratio) = 1680(rpm at wheels)
multiplied by 37(tyre circumference, in inches) = 62160(inches per minute)
multiplied by 60(minutes in one hour) = 3729600(inches in one hour)
divided by 63360(inches in one mile) = 58.863636.
or 58.86 mph

Message Thread:

Gearing Ratio by 'pratty' (31 Mar 2010 @ 21:36)

Re: Gearing Ratio by 'Bod' (31 Mar 2010 @ 21:50)

Re: Gearing Ratio by 'StressedMum' (31 Mar 2010 @ 22:53)

junior school maths ?? by 'Chads' (31 Mar 2010 @ 23:02)

Microsoft Excel!!! by 'michaelg36' (31 Mar 2010 @ 23:08)

Re: Microsoft Excel!!! by 'TeamKermit' (31 Mar 2010 @ 23:14)

Re: Microsoft Excel!!! by 'Bod' << You are here!

Re: Microsoft Excel!!! by 'itpro' (01 Apr 2010 @ 1:22)

Ratio is not needed .. by 'Chads' (01 Apr 2010 @ 2:21)

Steve........... by 'colin' (01 Apr 2010 @ 20:00)

Re: Steve/Colin & Chads by 'UrbanTiger' (01 Apr 2010 @ 22:48)

Re: Steve/Colin & Chads by 'pratty' (02 Apr 2010 @ 20:07)

Re: Steve/Colin & Chads by 'Hootsman' (02 Apr 2010 @ 20:50)

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