ToolBox

Suspension Geometry – Conversion between mm and degrees

Introduction

"ToolBox" now offers the conversion and calculation of suspension setting data in millimeters and degrees. This is important for vehicle track setting (suspension geometry). Depending on the vehicle manufacturer, the data for adjusting the suspension are specified either in mm or degrees. For modern vehicles mostly in degrees. However, with the simple means applied in the common "hobby garage" only millimeters can be measured. This new feature in "ToolBox" allows you to convert between degrees (metric and sexagesimal) and mm. Thus, the track can be adjusted in your private garage with the old "string method" simply by measuring millimeters.

Manual

Enter the values you'd like to convert into the upper three input fields. Please, use the dot (".") as decimal point. The uppermost field is for entering values of millimeters (e.g.: 1.5 mm), decimal degrees (e.g.: 1.5°) or sexagesimal degrees (e.g.: 1°). In the latter case, please enter integers only, as all decimals will be truncated anyway. This is also true for entering minutes and seconds in fields two and three.

Then choose the input-unit and – if applicable – the wheel size. The wheel size is important for the conversion from data in millimeters to degrees and vice versa, and is only applied in these cases. If you change the wheel size, the result will be updated automatically.

The rim flange type

The following checkbox allows you to choose, whether the calculation takes account of the rim type or not. This option is active by default and the calculation takes account of the rim type "J". This is most common rim type for light vehicle (automobile) wheels. You'll find this information on the wheel or in the vehicle documents (e.g.: 7,5Jx 16 H2 ET15). At the moment, unfortunately, no other rim type data are available.

Why is this information important? The wheel size in inch corresponds to the inner diameter of the tyre in use. The diameter of the wheel is measured between the wheel shoulders. The rim is the outer component of the wheel and the rim flange or edge is its bent over outermost part forming the outer edge of the wheel. Using the "string method", measures are taken on the outer edge of the wheel. Therefore, the height of the rim flange, which adds to the nominal diameter of the wheel, has to be included into the calculation.
Only deactivate this option if the design of the rim flange does NOT correspond to the index "J".

Custom wheel diameter

You may measure the diameter of your wheel yourself (from outer edge to outer edge), and use this measure (millimeters only). E.g., if your wheel does'n't show the J-type rim edge.

More settings

The checkbox "Total value for wheel alignment" is another important setting. If this option is active, the result will be the total value for wheel alignment, as its name implies. Wheels should be aligned equally on the left and the right hand side: If the total value for the track setting is 1.2 mm, the left and the right wheel should both show a toe in (or toe out) of 0.6 mm. Do also check that the wheels are turning equally (see manufacturer's data)!
Leave this option deactivated, if your input-value already applies to the total value for the track setting! Also deactivate this option, if you want to convert degrees to millimeters, e.g. to set the camber.

Please note: The calculation could produce rounding errors. These should, however, be negligible. At least when using the "string method" in your private garage ;-)

Important notes

THERE IS ABSOLUTELY NO GUARANTEE / WARRANTY CONCERNING THE ACCURACY AND PRECISION OF THE RESULTS!

The web-apps on the Minetosh online website are meant for information purposes only. The entire risk as to the quality, accuracy, precision and performance of these programs is with you! ALSO NO RESPONSIBILITY WHATSOEVER WILL BE ACCEPTED FOR ANY OTHER RISCS THAT GO BEYOND THIS. In particular, any damage or any other inconveniences (for example data loss) that may arise from the installation and / or use of these programs and the data produced by them (e.g. should the programs / results prove defective / erroneous)!

ATTENTION: Please keep in mind that suspension parts are security-relevant components! Always consult the technical data and a workshop manual for your vehicle. Only work on suspension components, if you know what you're doing. If in doubt, seek professional help and get the suspension geometry adjusted professionally!