Sprocket and Pump Speed


  • Find the diameter of the cart wheel in inches
  • Divide the inches by 12 to get diameter in feet
  • Next find the circumference of the wheel … C = 3.14 x diameter = x number of feet
  • Next find how many revolutions the wheel turns per minute …

miles per hour x 5280 ft = x number of feet / C in feet / 60 minutes = x rev per minute


Cart wheel measures 61.5 inches in diameter. Divide by 12 inches = 5.12 feet in diameter
Circumference then is 3.14 x 5.12 = 16 feet
If you are traveling at 5.5 mph, the revolutions of the wheel per minute is:
5.5 x 5280ft = 29040 ft traveled in 1 hour/ C of the wheel (16 ft) = 1815 rev per hour/60 min = 30 rev/min
To determine the sprocket needed to drive the pump at 350 to 450 rev/min you need to:

You have a 48 tooth sprocket attached to the inside of the cart wheel.
It drops down to a 12 tooth sprocket to drive the seeding mechanism, therefore, the shaft on this part is turning…4 times faster than the wheel sprocket ( 30 rev/min x 48tooth/12tooth) = 120 rev/min

We need to be around 400 rpm for the ALPINE pump so we need it to be 400/120 or about 3.3 times faster. Since the sprocket on the pump is a 10 tooth, we would need to add a 35 tooth (#40) sprocket. Adding this size sprocket would then drive the pump at 120 rev/min x 35tooth/10tooth = 420 rev/min

To download a pdf of this document of this information, click here.

Featured Product All


Liquid Fertilizer

ALPINE G22 is applied in the seed furrow for maximum plant benefits. Its formulation is low in salt, and impurities; making it seed safe for even the most sensitive crops.