Step 1: find out your tyre's rolling radius
Enter these details
Width (mm)
Profile (%)
Rim size (inch)
Rolling radius (feet)
Or enter radius:
(this cell must be empty to use the calculator cells, above)
Step 2: gear ratios
1st
:1
2nd
:1
3rd
:1
4th
:1
5th
:1
6th
:1
7th
:1
Final
:1
Step 3: shift RPM
Shift point in RPM
 
Road Speed vs Engine Speed
Graph represents speed in:
 
                           
         
         
         
         
         
         
       
       
                               
                               
1st gear 2nd gear 3rd gear
4th gear 5th gear
6th gear 7th gear
0
0.00 0.00 0.00
0.00 0.00
0.00 0.00
1
2
3
4
5
6
7
8
This calculator is provided as-is and is for informational purposes only.
Click here to contact Competition Transmission Services www.gearboxman.co.uk for more information.
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