What is the deal with Newton meters? I ordered stiffer 0.49 kg/mm fork springs for my bike, but the dealer told me that my bike came stock with 4.8 N/m springs. What’s the difference?
Every manufacturer is switching to N/m (Newton meters) just to mess with its customers. We’ve gone from pounds to kilograms to Newtons for no rhyme or reason. Luckily, the difference between a Newton number and a kilogram is not very great. The correction factor is to multiply the Newton number by 0.102 (and move the decimal point).
Thus, a 4.8 N/m fork spring is a 0.49 kg/mm spring. As a quick rule of thumb, the Newton meter number can be extrapolated to be one rate stiffer in kilograms, thus a 4.5 N/m spring would be a 0.46 kg/mm spring.
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