hope this helps some of you out
i plotted out the differant gearing options for blasters
idk what the limits aer so i went a few up and down from stock on both gears
the top number is the rear(axle) sprocket and the side numer is the front(motor) sprocket
ok so i forgot about the primary drive, and i dont want to redo all the mathz
here is a link provided by our friend quadrider10 that takes all the thought out of it
http://www.celicatech.com/luni/gearingcalculator.html
****disregard below*****
hopefully this will help other compensate for the changes in tire size on the rear
tire circumferance is pi*D
tire size - circ (in) - circ(ft) - circ(mi)
18 - 56.52 - 4.71
19 - 59.66 - 4.97
20 - 62.80 - 5.23
21 - 65.94 - 5.49
22 - 69.08 - 5.75
gear ratios
1st 3.091:1
2nd 2.214:1
3rd 1.667:1
4th 1.250:1
5th 1.056:1
6th .905:1
and now for the new mathz you wrench monkeys
now you can ((rpm/ratio/gear*circFT)*60)/5280 to get your speed at a given rpm
the max rpm of a blaster IIRC is 10,500
so 10,500[theoretical redline]/3.08[stock 13/40]/.905[6th gear]*5.75ft[22in tire] = {168289fpm * 60)/5280 = 246mph
now this is obviously wayyy unlikely but you would have to redline 6th for that to happen
air drag, hp, weight etc are not factored into this equation
lets say 3rd gear 22in tires stock gearing theoretical redline
((10,500/3.08/1.667*5.75)*60)/5280 = 133mph
again unlikely so what is a realistic redline
lets say 6k in 1st gear
((6000/3.08/3.091*5.75)*60)/5280 = 41mph
somewhere in here my math is off theres no way you can do 41mph in first
if you lifted the rear off the floor and pegged it in the shop this might be possable
maybe its the redline? does anyone know the realistic redline of a stock blaster?
someone help fill in my gaps as this would make a great sticky
lets try some reverse math
a stock blaster top speed is 58mph
58*5280/60 = 5104fpm / 4.71ft[18inch tire] = 1083.65[axle rpm] *3.08*.905[6th] =3020rpm
lets use that
3020 redline stock gears 22" tires
((3020/3.08/.905*5.75)*60)/5280 = 70mph
now we're getting some where lets play with gears now lets go down a tooth to a 12 on the front
((3020/3.33/.905*5.75)*60)/5280 = 65mph
almost there lets go up 1 in the back now 12/41
((3020/3.41/.905*5.75)*60)/5280 = 63mph
12/42 3.50
((3020/3.50/.905*5.75)*60)/5280 = 62.3mph
12/44
((3020/3.67/.905*5.75)*60)/5280
also lets move some sh*t around so its easier
3020/.905*5.75*60/5280=218.04 /3.67 == 59.41mph
so to have the same speed at the same rpm as stock but with 22in tires you would need to run 12/44 gears
this is theory in the real world on modified bikes with differant power bands all this will change
i plotted out the differant gearing options for blasters
idk what the limits aer so i went a few up and down from stock on both gears
the top number is the rear(axle) sprocket and the side numer is the front(motor) sprocket
ok so i forgot about the primary drive, and i dont want to redo all the mathz
here is a link provided by our friend quadrider10 that takes all the thought out of it
http://www.celicatech.com/luni/gearingcalculator.html
****disregard below*****
hopefully this will help other compensate for the changes in tire size on the rear
tire circumferance is pi*D
tire size - circ (in) - circ(ft) - circ(mi)
18 - 56.52 - 4.71
19 - 59.66 - 4.97
20 - 62.80 - 5.23
21 - 65.94 - 5.49
22 - 69.08 - 5.75
gear ratios
1st 3.091:1
2nd 2.214:1
3rd 1.667:1
4th 1.250:1
5th 1.056:1
6th .905:1
and now for the new mathz you wrench monkeys
now you can ((rpm/ratio/gear*circFT)*60)/5280 to get your speed at a given rpm
the max rpm of a blaster IIRC is 10,500
so 10,500[theoretical redline]/3.08[stock 13/40]/.905[6th gear]*5.75ft[22in tire] = {168289fpm * 60)/5280 = 246mph
now this is obviously wayyy unlikely but you would have to redline 6th for that to happen
air drag, hp, weight etc are not factored into this equation
lets say 3rd gear 22in tires stock gearing theoretical redline
((10,500/3.08/1.667*5.75)*60)/5280 = 133mph
again unlikely so what is a realistic redline
lets say 6k in 1st gear
((6000/3.08/3.091*5.75)*60)/5280 = 41mph
somewhere in here my math is off theres no way you can do 41mph in first
if you lifted the rear off the floor and pegged it in the shop this might be possable
maybe its the redline? does anyone know the realistic redline of a stock blaster?
someone help fill in my gaps as this would make a great sticky
lets try some reverse math
a stock blaster top speed is 58mph
58*5280/60 = 5104fpm / 4.71ft[18inch tire] = 1083.65[axle rpm] *3.08*.905[6th] =3020rpm
lets use that
3020 redline stock gears 22" tires
((3020/3.08/.905*5.75)*60)/5280 = 70mph
now we're getting some where lets play with gears now lets go down a tooth to a 12 on the front
((3020/3.33/.905*5.75)*60)/5280 = 65mph
almost there lets go up 1 in the back now 12/41
((3020/3.41/.905*5.75)*60)/5280 = 63mph
12/42 3.50
((3020/3.50/.905*5.75)*60)/5280 = 62.3mph
12/44
((3020/3.67/.905*5.75)*60)/5280
also lets move some sh*t around so its easier
3020/.905*5.75*60/5280=218.04 /3.67 == 59.41mph
so to have the same speed at the same rpm as stock but with 22in tires you would need to run 12/44 gears
this is theory in the real world on modified bikes with differant power bands all this will change
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