RPM/MPH Calculation

[Flameout]

Has anybody calculated the engine rpm ratio to the 10 tooth sprocket on the HT engines?
I don't want to "re-invent the wheel" if I not necessary. I could then use rear sprocket size
and wheel diameter to determine engine rpm from speed.

Thanks for any input.

[Forbisher]

Download the ratio calculator
Index of /ratiocalc

Input
20 for drive gear for the bevel crank

82 for driven gear for the clutch gear

4:1 to 1 ratio for the Chinese 2 stroke engine

[Flameout]

Thanks Forbisher, for my wheel diameter and 44 tooth sprocket it is 222 rpm = 1 mph.

[Cabinfever1977]

that ratio calulator said i would do 132mph @ 7000rpms,lol.
i have a 44t sprocket with 26" wheels.

[Forbisher]

Originally Posted by Cabinfever1977

that ratio calulator said i would do 132mph @ 7000rpms,lol.
i have a 44t sprocket with 26" wheels.

7000 rpm = 30.0 mph in your case

The calculator worked fine for the guy above
and for myself
I have been calculating ratios for the EZ 4 stroke bike to
figure out rear belt sizes and it is invaluable

You entered the wrong figures so try again
Read the help file at the bottom

20 for drive gear for the bevel crank

82 for driven gear for the clutch gear

in one field

then

10 for drive gear

44 for driven gear

leave the other box at 1

[Cabinfever1977]

thanks forbisher i know how to use it now and its working good.