Spring rate test?

TTperra
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TTperra
Edited Date/Time 1/19/2016 10:53am
I have a couple sets of front springs, but I don't know what rate they are.
Does anyone know a way to test them?

Thought of using a bathroom scale, compress the spring 20mm and se which one is hardest.. some one tried this?
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Kidkawie
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Kidkawie 1/18/2016 6:28pm
1/18/2016 6:28pm
Broom handle, some dumbell weights, tape measure and a calculator.
wolfy0067
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wolfy0067 1/19/2016 6:29am
1/19/2016 6:29am
Intercomp sells a kit, if not speak with a shop that will perform accurate testing for you. I have several sets myself I am not sure of anymore
450exc115
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450exc115 1/19/2016 7:57am
1/19/2016 7:57am Edited Date/Time 1/19/2016 6:06pm
You can get a rough idea of spring rate if you measure wire size, od and count the number of active coils. Racing suspension products has a rate calculator on there website. It will get you in the ball park.

Most spring manufacturers publish rates after 20mm of compression due to finishing tolerances so just keep that in mind if you mechanically determine the rate.
TTperra
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TTperra 1/19/2016 9:41am
1/19/2016 9:41am
Thanks, will try that calculator for a start.
Probably buying new springs later

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Matt Fisher 1/19/2016 9:50am
1/19/2016 9:50am
Kidkawie wrote:
Broom handle, some dumbell weights, tape measure and a calculator.
Could you be a bit more specific?
nage0139 1/19/2016 10:32am
1/19/2016 10:32am
Kidkawie wrote:
Broom handle, some dumbell weights, tape measure and a calculator.
Matt Fisher wrote:
Could you be a bit more specific?
F = k*x

F=force exerted
k=spring constant
x=distance the force compressed the spring

So weighting a spring and measuring how far it compresses will give you it's spring constant k, which is the spring rate.

Hope that helps!
Kidkawie
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Kidkawie 1/19/2016 10:53am
1/19/2016 10:53am
Put the broom handle in a vise, place spring over handle, add weight (kg), measure how far spring compresses (mm)

kg / mm = rate

Also, test with extra preload. Say you start with 10kg, do test. Remove weight, add 20kg, measure (zero), add original 10kg and measure from zero. Should be same as first test or very close to it.

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