Continuing with our Springs 101 series, we wanted to briefly touch on conversion between the two standard ways of listing spring rate measurements. If you didn’t read the last installment, we suggest doing so; you can find that here.
So, if you’re trying to compare spring rates of various suspension offerings and are stuck looking at rates in both forms of measurement, there is an easy solution: Google. If you’re trying to find out what a 5k spring would be in lb/in simply open Google and search “5kg/mm to lb/in” and they will pump out the conversion for you. This will work both ways. If you’re trying to find what a 500lb/in spring would be in kg/mm just search “500lb/in to kg/mm”. It’s important to not forget both units of measurement when searching; the weight (kg or lb) and the distance (mm or in). Leaving out one of these will not produce results from the search (searching 5k to lb/in is only going to get you a video of a 570 lb man finishing a 5k run).
PROPER SEARCH TERM
500lb/in to kg/mm
IMPROPER SEARCH TERM
5k to lb/in
Don’t have Google handy? Well there is another easy way: you can divide or multiple by 56. If you’re trying to find that same 5k to lb/in then just multiply 5 x 56 = 280. While Google will give you the most accurate result, 279.987, the rule of 56 is close enough that we wouldn’t think twice about using that method. If you’re trying to find 500lb/in to kg then simply divide 500 / 56 = 8.929 (this typically can be read as 8.9k or rounded up to 9k).
