Re: Calculating speed, diff ratio, tire size etc.

[Mark J Bradakis <mjb@cs.utah.edu>]

There've been a couple of spreadsheets in the Team.Net FTp archives
to do things like this.  One, a simple Unix sc spreadsheet, allows you to
enter the tire diameter, aspect ratio and section width, and gives you
something like the following, once you've plugged in the proper gear ratios:

     Section Width (mm) >>       205
           Aspect Ratio >>        55
Wheel Diameter (inches) >>     15.00
   Wheel Width (inches) >>      6.00
    Section Width (inches)      8.07
   Section Height (inches)      4.44
 Overall Diameter (inches)     23.88

         Rear end ratio >>      3.70

Transmission ratios              1st       2nd       3rd       4th       5th
                        >>      3.50      2.16      1.39      1.00      0.83


                       RPM       1st       2nd       3rd       4th       5th

                    1500.00      8.23     13.33     20.72     28.80     34.70
                    2000.00     10.97     17.78     27.63     38.40     46.26
                    2500.00     13.71     22.22     34.53     48.00     57.83
                    3000.00     16.46     26.67     41.44     57.60     69.40
                    3500.00     19.20     31.11     48.34     67.20     80.96
                    4000.00     21.94     35.55     55.25     76.80     92.53
                    4500.00     24.69     40.00     62.16     86.40    104.09
                    5000.00     27.43     44.44     69.06     96.00    115.66
                    5500.00     30.17     48.89     75.97    105.60    127.23
                    6000.00     32.91     53.33     82.88    115.20    138.79
                    6500.00     35.66     57.78     89.78    124.80    150.36
                    7000.00     38.40     62.22     96.69    134.40    161.92
                    7500.00     41.14     66.67    103.59    144.00    173.49


This is found in the /misc directory of ftp.team.net, as is tires.excel, which
is an Excel spreadsheet for a similar purpose.

mjb.