I'm trying to calculate through the driveline gears of the Savage 2-speed and 3-speed in order to approximate road speed given no variables (power, drag, tire growth, etc.). The mathematics aren't the problem, the Savage's transmissions are the problem, or the gears therein.
From what I see in my Savage 21 manual, when in second gear, the top shaft is using the 23-tooth gear to spin the 39-tooth gear on the idler shaft, then the gear at the end of the idler shaft (32-tooth) drives the 29-tooth gear on the bottom (output) shaft. So input to output I get 23/39*32/29 = 0.65075.
Applying that to the 3-speed, the largest gear on the top shaft is 24-tooth, it mates to a 38-tooth gear on the idler, the gear at the end of the idler driving the output shaft gear is a 31-tooth, and the output shaft gear itself is a 30-tooth. Thus 24/38*31/30 = 0.65263.
There's a difference, but it's EVER so slight, and given the same rpm, bell, spur, and tire diameter, the difference in top speed is less than a tenth of a mile per hour. HPI claims 10% higher top speed potential due to the different gearing in the 3-speed, so obviously I'm doing something wrong....or is HPI's advertising more than a little misleading?
From what I see in my Savage 21 manual, when in second gear, the top shaft is using the 23-tooth gear to spin the 39-tooth gear on the idler shaft, then the gear at the end of the idler shaft (32-tooth) drives the 29-tooth gear on the bottom (output) shaft. So input to output I get 23/39*32/29 = 0.65075.
Applying that to the 3-speed, the largest gear on the top shaft is 24-tooth, it mates to a 38-tooth gear on the idler, the gear at the end of the idler driving the output shaft gear is a 31-tooth, and the output shaft gear itself is a 30-tooth. Thus 24/38*31/30 = 0.65263.
There's a difference, but it's EVER so slight, and given the same rpm, bell, spur, and tire diameter, the difference in top speed is less than a tenth of a mile per hour. HPI claims 10% higher top speed potential due to the different gearing in the 3-speed, so obviously I'm doing something wrong....or is HPI's advertising more than a little misleading?