Fabian
Well-Known Member
From the 10T clutch output shaft sprocket to the Jackshaft 17T sprocket = 1.7:1
Jackshaft right hand side sprocket is a 9T which drives the SickBikeParts optional 48T pedal crank sprocket = 5.33:1
In low range gear (selected by the front derailleur) i am running the optional SickBikeParts 24T sprocket
In Midrange gear i am running the SickBikeParts optional 30T sprocket
In High range gear i am running the SickBikeParts standard 36T sprocket
The rear cassette is a jail broken set of (9 speed) Shimano style cassette sprockets made up from two individual cassette clusters, giving me the following sprocket sizes:
11 - 12 - 13 - 14 - 16 - 19 - 23 - 28 - 36
In low range and with 1st gear selected the sprocket ratio is 1.5:1
In high range and with the top gear selected the sprocket ratio is 1:3.272
The total (chain driven) gearing value in low range first gear is 13.592:1
The total (chain driven) gearing value in High range top gear is: 2.764:1
Engine primary gear ratio = 4:1
Low range first gear - 13.592 * 4 = 54.368
High range top gear - 2.764 * 4 = 11.056
Wheel circumference = 2.065 meters
Low range first gear = 54.368 engine rpm per wheel revolution.
High range top gear = 11.056 engine rpm per wheel revolution.
5mph = 8.05 kilometers per hour
30mph = 48.3 kilometers per hour
8,050 meters / 60 = 134.166 meters per minute
48,300 meters / 60 = 805 meters per minute
134.166 / 2.065 (wheel circumference) = 64.971 (rear wheel rpm per minute) - 1.082 wheel rpm per second
805 / 2.065 (wheel circumference) = 389.830 (rear wheel rpm per minute) - 6.497 wheel rpm per second
64.971 * 54.368 = 3,532 engine rpm in low range first gear @ 5mph - - - - - 58.866 engine revolutions per second
389.830 * 11.056 = 4,309 engine rpm in high range top gear @ 30mph - - - - - 71.816 engine revolutions per second
High range first gear = 7.514mph (12.097km/h) @ 3,532 engine rpm
The rear cassette has a 327.2% over drive between first gear and top gear, if you like playing with numbers and want to work out gear ratio combinations.
Jackshaft right hand side sprocket is a 9T which drives the SickBikeParts optional 48T pedal crank sprocket = 5.33:1
In low range gear (selected by the front derailleur) i am running the optional SickBikeParts 24T sprocket
In Midrange gear i am running the SickBikeParts optional 30T sprocket
In High range gear i am running the SickBikeParts standard 36T sprocket
The rear cassette is a jail broken set of (9 speed) Shimano style cassette sprockets made up from two individual cassette clusters, giving me the following sprocket sizes:
11 - 12 - 13 - 14 - 16 - 19 - 23 - 28 - 36
In low range and with 1st gear selected the sprocket ratio is 1.5:1
In high range and with the top gear selected the sprocket ratio is 1:3.272
The total (chain driven) gearing value in low range first gear is 13.592:1
The total (chain driven) gearing value in High range top gear is: 2.764:1
Engine primary gear ratio = 4:1
Low range first gear - 13.592 * 4 = 54.368
High range top gear - 2.764 * 4 = 11.056
Wheel circumference = 2.065 meters
Low range first gear = 54.368 engine rpm per wheel revolution.
High range top gear = 11.056 engine rpm per wheel revolution.
5mph = 8.05 kilometers per hour
30mph = 48.3 kilometers per hour
8,050 meters / 60 = 134.166 meters per minute
48,300 meters / 60 = 805 meters per minute
134.166 / 2.065 (wheel circumference) = 64.971 (rear wheel rpm per minute) - 1.082 wheel rpm per second
805 / 2.065 (wheel circumference) = 389.830 (rear wheel rpm per minute) - 6.497 wheel rpm per second
64.971 * 54.368 = 3,532 engine rpm in low range first gear @ 5mph - - - - - 58.866 engine revolutions per second
389.830 * 11.056 = 4,309 engine rpm in high range top gear @ 30mph - - - - - 71.816 engine revolutions per second
High range first gear = 7.514mph (12.097km/h) @ 3,532 engine rpm
The rear cassette has a 327.2% over drive between first gear and top gear, if you like playing with numbers and want to work out gear ratio combinations.
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