need a math guy
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From: ST. Louis
Road Warrior
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From: Cheltenham, UK
Road Master
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From: Annemasse (border of Geneva-Switzerland) facing Mt-Blanc.
hoggy05 asked for a math guy to give him the speed his bike is doing at 3,000rpm. As an engineer I use applied math and it was too tempting to give him the answer as a math equation! Iron Butt has correctly identified the tyre diameter and gear ratio.
It's the weekend after all, time for a little fun!
It's the weekend after all, time for a little fun!
A normal value is 3% depending on grade of incline and wind. 3,000 RPM is 129 KM/H on my GPS
Road Warrior
Joined: May 2007
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From: Austin, TX - Some call it heaven.
My nephew is mathematically challenged. I told him to try logic instead of math. He asked me what I meant. Well, supposed the problem is "What's 80% of 375?" You could do it by multiplication, or you could say: "10% of 375 is 37.5, so 20% is 75. 375 - 75 = 300. See, you're using logic to break it down to the easiest way to solve it.
In this case you could use math to figure how how fast the wheel is turning for a given RPM and gear size, then factor in things like tire pressure, temperature of the road surface, aerodynamics, etc.
Or you could use logic and look down at the speedometer.
In this case you could use math to figure how how fast the wheel is turning for a given RPM and gear size, then factor in things like tire pressure, temperature of the road surface, aerodynamics, etc.
Or you could use logic and look down at the speedometer.
Last edited by bluffalobob; Apr 29, 2012 at 06:46 PM.
Road Captain
Joined: Jan 2009
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From: St. Louis
Here's a link to one of my favorite websites, you could 'play' for hours on here.
http://www.wallaceracing.com/Calculators.htm
http://www.wallaceracing.com/Calculators.htm
Road Master
Joined: Jun 2011
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From: Chesapeake Virginia
Considering your post location it looks like incline and altitude has a little to do with this answer.
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From: Bedford UK
Interestingly Avon spell it correctly on their US website!
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Whoa! Somebody say something about pie? I admit, I got lost at the bakery when all that math was being bantered about. But pie, that is something I can really get my hands on. Are we talkin apple, cherry, peach or whatever? There is no such thing as bad pie.
