Chain & Sprocket Calculator

Calculate final drive ratio, top speed at redline, and cruising RPM. See the effect of going up or down a tooth before you buy.

Quick Presets

Current Sprockets

Ratio: 2.471:1

Proposed Sprockets

Ratio: 2.588:1

Engine & Tire

inches custom

Side-by-Side Comparison

MetricCurrent (17/42)Proposed (17/44)
Final Drive Ratio2.471:12.588:1
Top Speed (at redline)470 MPH449 MPH
RPM at 60 MPH1,5321,605

Speed change: -4.5% lower gearing (more torque, less top speed)

Sprocket Tuning Rules of Thumb

−1 front tooth ≈ +3–4 rear teeth in ratio change. Front changes are cheaper and easier.

Larger rear / smaller front: more acceleration, lower top speed, higher cruising RPM.

Smaller rear / larger front: better top speed, lower highway RPM, less low-end pull.

• Check chain length requirements after any sprocket change — you may need to add or remove links.

• Always replace chain and both sprockets together for even wear.