View Full Version : Ratio vs. Motor relationship
11-02-2002, 11:34 PM
I don't understand the relationship between a gear ratio and the turn of a motor. If I have a Sappire, and gear it 15/87, that gives me a 5.80 ratio. If I have an Onyx, and gear it 12/87, that gives me 7.25. I know the lower the ratio, the faster you will go, but isn't that the same with motors. The lower turn, the faster it is. Then why can't I use the same ratios with different turn motors. Doesn't the 7.25 ratio with the Onyx mean more torque and less speed? Isnt' that supposed to be a faster motor? What if I wanted to gear it at 5.80 to make it faster? Would this be ok? Please help me understand this.
11-02-2002, 11:53 PM
You have to gear down with a lower turn motor to give it some torque to reach the higher speeds. Without the lower gearing, the motor will overheat when it's overworks itself trying to get up to it's intended RPM range. That is if it can even get there at all.
It's similar to the transmission in a car. You can't start out in 5th gear. You need some torque to get the car moving first.
11-03-2002, 07:43 AM
well put Misbe...
this is the reason I don`t promote low turn motors in a pede (with stock size tires) . IMO 14 is the lowest the pede can use with an 87 spur and still have some veriance in gearing .
all motors have what I call a power band , it`s the point when the motor is produceing the most power and torqe .
the 17 is a good low to mid range motor , not that it won`t go fast because it will .
a 12 or lower has to get up into the mid to upper part of it`s rpm`s to get to it`s power .
if your just bashing then stay with the higher turn motors , you will be much happier with your truck .
if you want to put street tires on it and go fast then a lower turn motor will work better for you .
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