The engineering
behind your setup.
Practical guides, technical explanations and real-world insights to help you understand your setup and make informed changes.
30 guides · Showing 16–30
Go-kartHow to read a go-kart gear ratio chart
A gearing chart compares front and rear sprocket combinations at a common operating point. Read the row and column labels before interpreting either reduction or speed.
Go-kartGo-kart gearing: acceleration versus top speed
More reduction increases ideal wheel torque for a given engine torque, while lowering wheel speed at a given engine RPM. Neither relationship alone predicts lap time.
Go-kartHow go-kart sprocket sizes affect speed
A larger rear sprocket or a smaller front sprocket increases reduction. Compare the percentage ratio change to understand how large a tooth change really is.
Go-kartHow to calculate go-kart speed from RPM
Find axle RPM by dividing engine RPM by overall reduction. Multiply axle RPM by tire circumference to get distance per minute, then convert to your chosen speed unit.
Go-kartGo-kart torque converter ratios explained
A belt converter varies its drive ratio with operating conditions. Use a selected instantaneous reduction in a calculation, then repeat for another point instead of treating it as one permanent ratio.
Mini bikeMini-bike sprocket selection: calculate the change
Select a proposed sprocket by quantifying the change from your existing setup. Begin with a combination whose real behavior you already understand.
Mini bikeMini-bike top-speed calculations and their limits
An RPM-based speed calculation answers how fast the wheel would travel at an entered RPM. It does not determine whether the engine can sustain that RPM against real resistance.
MotorcycleMotorcycle sprocket ratio: final drive versus overall gearing
Rear teeth divided by front teeth gives motorcycle chain final reduction. Overall reduction also includes the primary drive and the selected transmission gear.
MotorcycleMotorcycle gearing and acceleration trade-offs
A higher final reduction increases ideal rear-wheel torque at equal engine torque. Actual acceleration depends on engine RPM, traction, wheel lift and shift timing.
Dirt bikeDirt-bike sprocket selection in percentages
Front and rear tooth changes have different percentage effects. Calculate the proposed ratio rather than describing every one-tooth change as equally large.
DrivetrainHow to calculate gear ratio from RPM and speed
Rearrange the road-speed relationship to infer overall reduction: R = engine RPM × circumference ÷ distance traveled per minute. Measurements must refer to the same steady operating point.
DrivetrainRPM to MPH: conversion with circumference and gearing
RPM is rotational speed; MPH is distance per time. A conversion needs wheel travel per revolution and the reduction between the measured shaft and wheel.
Drag racingTrap speed, horsepower and weather
Trap speed describes an end-of-run timing measurement. It is not the average speed over the whole run, and a trap-speed power estimate is not a dyno measurement.
Drag racingEighth-mile to quarter-mile conversion limits
A multiplier converts an eighth-mile ET into a provisional quarter-mile estimate. No universal multiplier accounts for every vehicle’s acceleration in the second half of the run.
EngineeringChain drive calculations: pitch advance and shaft speed
Each driving sprocket revolution advances a number of chain pitches equal to its tooth count. This gives average chain speed without approximating the pitch polygon as a circle.