Spring Rate Calculations
When calculating your dual spring rates we request you complete the following steps with your existing setup and supply the information gathered in this process:-
NB The Driver and Co-driver should be in the vehicle when taking these measurements and the vehicle should be as close to "ready to race" condition as possible.
Step 1 - Fill in your Name, Phone and Email address in the boxes below.
Step 2 - Record the Shock Absorber Type and Shock Absorber Travel in the boxes provided
Step 3 - Adjust the spring pre-load rings to obtain the required ride height (even if the springs are loose at full extension, )This is VERY IMPORTANT.;
Step 4 - With the vehicle at ride height, ensure the crossover ring (if fitted) is not positioned against the spring divider **
Step 5 - Measure the overall lengths of each individual spring at ride height (we call this Nominal length). Record this information in the Nominal Length boxes.
Step 6 - Jack vehicle up so wheels are off the ground and suspension is at full droop.
Measure each spring length and record these measurements in the Installed Length boxes.
If there is a gap between the top the spring and the spring preload ring at this point,
divide the gap by two and add half the gap to the lower springs and half the gap to the upper springs.
Step 7 - Remove springs from shock. Measure and record the existing rate and length record this in the Free Length boxes.
Step 8 - Spring Envelope: We use this information to decide the correct length of springs needed.
This is the length of longest possible single spring that could be fitted to the shock absorber .
It should be measured from the under side of the threaded spring preload ring (top spring platform) to the top side of the lower spring retainer (lower spring platform) which is situated on the bottom of the shaft.
Remove the plastic spring divider, wind the spring preload ring to the top,
extend the shock fully and measure the distance between the top and bottom spring platforms.
Record the measurement the Spring Envelope box.
Step 9 - Thread Envelope: We use this information to determine the length of the upper spring.
On the body of the shock absorber, record the total length of the spring preload ring thread in the Thread Envelope box.
Step 10 - Record Spring Rates in the Spring Rate boxes
Step 11 - Hit Send button
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**This can confuse how much preload is required to achieve correct ride height.
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Front
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Rear
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Shock Absorber Type
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Shock Absorber Travel
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Spring Rate
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O/S |
N/S |
O/S |
N/S |
Free Length
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Installed Length
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Nominal Length
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Thread Envelope
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Spring Envelope
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Notes
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We have the facility to measure spring rates if you cannot identify your existing spring rates.
When finished you should have recorded the Free, Installed and Nominal length of each individual spring together with the amount of positive or negative preload and the existing rate.
From this information we should be able to advise on optimum springs for your vehicle.
N.B. We only offer springs rate calculations as a service when customers have purchased shocks and springs from us.