Tire RPM-KM H charts  
Choose your tiresize (or the one nearest) , go down to your final drive-ratio, then to the right to see what KM/H you go at what RPM.

10"-145 165 1000rpm  2000rpm  3000rpm  4000rpm  5000rpm  6000rpm  7000rpm  8000rpm        

2.95 : 1    31.11     62.22    93.33    124.5    155.6    186.7    217.8               

3.10 : 1    29.7      59.4     89.1     118.8    148.5    178.2    207.9               

3.21 : 1    28.6      57.2     85.8     114.4    143      171.6    200.2               

3.44 : 1    26.68     53.37    80.05    106.7    133.4    160.1    186.8    213.5        

3.65 : 1    25.15     50.3     75.45    100.6    125.7    150.9    179      201.3        

  

12" -155 BR 160cm  1000rpm  2000rpm  3000rpm  4000rpm  5000rpm  6000rpm  7000rpm  8000rpm        

2.95 : 1            32.54   65.08    97.62    130.2    162.7    195.2    227.7               

3.10 : 1            31.06   62.13    93.2     124.3    155.3    186.4    217.5               

3.21 : 1            29.9    59.81    89.71    119.6    149.5    179.4    209.3               

3.44 : 1            27.90   55.81    83.72    111.6    139.5    167.4    195.3    223.2        

3.65 : 1            26.3    52.6     78.90    105.5    131.5    157.8    184.1    210.4        


13" -175 BR 162cm  1000rpm  2000rpm  3000rpm  4000rpm  5000rpm  6000rpm  7000rpm  8000rpm        

2.95 : 1            32.94   65.92     98.8    131.8    164.7    197.7    230.6               

3.10 : 1            31.45   62.9      94.4    125.8    157.3    183.5    209               

3.21 : 1            30.28   60.56     90.84   121.1    151.4    181.7    211.9               

3.44 : 1            28.25   56.51     84.7    113      141.3    169.5    197.8     226        

3.65 : 1            26.63   53.26     79.89   106.5    133.1    159.8    186.4     213        

  These numbers are  theoretical, calculated with  1 : 1 dropgears and 4speed box. KMH x 0.621 = MPH.