Im trying to figure out how to measure my speed without adding a gauge or driving next to a vehicle. Is it possible to use a formula that uses 3600rmp, 10 tooth drive sprocket, 60 tooth driven sprocket? Or does the driven sprocket not actually turn at 3600rmp (max rpm for my engine).
How to measure your speed?
- Thread starter dragon831
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devino246
Official DIYGK Chem Nerd
This site has a theoretical speed calculator
http://diygokarts.com/speed-calculator.html
Keep in mind that his is only theoretical and doesnt factor in drag.
http://diygokarts.com/speed-calculator.html
Keep in mind that his is only theoretical and doesnt factor in drag.
kendelrk
redneck engineer
somtimes things feel faster when your two inches from the ground
Doc Sprocket
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In order to accurately calculate your speed based on engine RPM is to know for sure the actual RPM you are running at speed. Without a tachometer, it's all guess work. The speed calculator will (as Devino stated) give you a theoretical number, but there are factors unaccounted for. Another thing worth noting is that your tire size is likely not exactly what is printed on the sidewall. With weight in the kart, meaure from dead centre of the wheel hub to the ground. This is your static loaded radius. Multiply this number by two, and enter it into the calculator as the diameter. This is as accurate as you're going to get for tire size.
If you don't have a tachometer to measure actual RPM, all you can do is guess. Without a tach or speedo, you're down to using a GPS or having a car (with a known accurate speedo) pacing you. If you're going to use a GPS, take several long passes of 30 seconds or more, and then average all the results. It takes a minute for the GPS unit to calculate the satellite info, so a quick 10-second pass will not be accurate, either.
If you don't have a tachometer to measure actual RPM, all you can do is guess. Without a tach or speedo, you're down to using a GPS or having a car (with a known accurate speedo) pacing you. If you're going to use a GPS, take several long passes of 30 seconds or more, and then average all the results. It takes a minute for the GPS unit to calculate the satellite info, so a quick 10-second pass will not be accurate, either.
Doc Sprocket
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Well- yes. Again, lots of factors involved, but all things considered, it's probably within +/- 3 mph.
Russ2251
AZUSA:Powered by LAWN-BOY
I use a TinyTach to monitor rpm.
My tires are 10.88 inches in diameter.
Using #35 chain, 17 tooth clutches, and 70 tooth drivens, I come up with this (so far) as my max speed.
I use this calculator.
This is the most accurate calculator I could find.
My tires are 10.88 inches in diameter.
Using #35 chain, 17 tooth clutches, and 70 tooth drivens, I come up with this (so far) as my max speed.
I use this calculator.
This is the most accurate calculator I could find.
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