Park Tool TM-1 Spoke Tension Meter. The Park Tool TM-1 Spoke Tension Meter is an essential tool for achieving that proper tension and belongs on the workbench of anyone building or truing wheels diagnosing wheel problems or assembling new bikes. The reading of the TM-1 can be used to help estimate the relative tension of a wheels spokes identifying areas with high or low tension. Using the included printed table or the Park Tool Wheel Tension App this measurement can be converted to kilograms-force in order to calculate the overall tension of a wheel and ensure that it is at the proper level. The Wheel Tension App also features interactive tools to help visualize and analyze a variety of data based on the TM-1s readings.