jrmints1415
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How does this ratio sound? 12 tooth to 18 tooth to 13 tooth to 60 tooth? I have 20 inch tires. What speed would i get with a degoverned engine??
Jackshaft gear ratio
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amcjavelin
amcjavelin
need to use the sprocket ratio calculator plus figuire in the size of rear tire and also top rpm that the engine will be allowed to run at
r97
Measure twice cut once
i suppose i would say its a little steep for a 6.5hp, but should work pretty good on flat ground.
Bluethunder3320
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on my bike project (the current one....) ive got 12t clutch, 13t jackshaft to 18t, to 50t...... sort of the reverse that you have, but i knew that putting the 18t first would be too high.
jrmints1415
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yea i got the same kit you did. should i use the 13 toth first? How fast would i go? What would be my final gear ratio?
Bluethunder3320
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you could always try it both ways. i am not sure how to figure out a ratio with a jackshaft, but i knew i was close anyways...
jrmints1415
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toy story where are u!
r97
Measure twice cut once
/ = dived
* = multiply
jack shaft input / clutch sprocket * axle sprocket / jack shaft output = overall ratio
max engine rpm / overall ratio = rpm of axle
circumfrance of rear wheel (for example, in inches) * rpm of axle = inches of vehicle travel per minute.
inches of vehicle travel per minute / 12 = feet of travel per minute
feet of travel per minute / 5280 = miles of travel per minute
miles of travel per minute * 60 = miles per hour
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example:
20 teeth on jack shaft input / 10 teeth on clutch = 2
45 teeth on axle / 10 teeth on jack shaft output = 4.5
2*4.5 = 9:1 overall ratio
3600 rpm / 9 = 400 rpm axle speed
11.5" tire DIA * pi = 36" tire circumfrance
36" circumfrance * 400 axle rpm = 14400 inches per minute of vehicle travel
14400 ipm / 12 inches (there are 12" in a foot) = 1200 feet per minute
1200 fpm / 5280 (5280 feet = 1 mile) = 0.22727272727272727272727272727273 miles per minute
0.22727272727272727272727272727273 mpm * 60 (60 min = 1hr) = about 13.63 MPH
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if you want you can just find the overall ratio and plug that into the calculator.
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to answer your question, having he 13t first would make about a 3.6:1 overall ratio, not good.
* = multiply
jack shaft input / clutch sprocket * axle sprocket / jack shaft output = overall ratio
max engine rpm / overall ratio = rpm of axle
circumfrance of rear wheel (for example, in inches) * rpm of axle = inches of vehicle travel per minute.
inches of vehicle travel per minute / 12 = feet of travel per minute
feet of travel per minute / 5280 = miles of travel per minute
miles of travel per minute * 60 = miles per hour
__________________________________________________
example:
20 teeth on jack shaft input / 10 teeth on clutch = 2
45 teeth on axle / 10 teeth on jack shaft output = 4.5
2*4.5 = 9:1 overall ratio
3600 rpm / 9 = 400 rpm axle speed
11.5" tire DIA * pi = 36" tire circumfrance
36" circumfrance * 400 axle rpm = 14400 inches per minute of vehicle travel
14400 ipm / 12 inches (there are 12" in a foot) = 1200 feet per minute
1200 fpm / 5280 (5280 feet = 1 mile) = 0.22727272727272727272727272727273 miles per minute
0.22727272727272727272727272727273 mpm * 60 (60 min = 1hr) = about 13.63 MPH
_____________________________________________________________
if you want you can just find the overall ratio and plug that into the calculator.
___________________________________________________________
to answer your question, having he 13t first would make about a 3.6:1 overall ratio, not good.
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