The BillaVista Preliminary Spring Rate Calculator - © 2008 Bill "BillaVista" Ansell, All Rights Reserved.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

Method -----> Suspension Height Suspension Frequency Front Rear Front Rear

InputsCSW (lbs) 806 613 806 613WT (in) 16 16 16 16d1 (in) 38 44 38 44d2 (in) 38 44 38 44alpha (˚) 5 2 5 2SH (%) 50 50SUR (%) 250 250 250 250Fn (Hz) 1.1 1.1

Target OutputsWRi(t) (lbs/in) 101 77 100 76DR 1 1 1 1ACF 0.9962 0.9994 0.9962 0.9994IR 0.9962 0.9994 0.9962 0.9994Fn(i)(t) (Hz) 1.106 1.106 1.100 1.100DTt (in) 7.9 8.0 8.0 8.1BTt (in) 8.1 8.0 8.0 7.9SHt (%) 50 50 50 50Ki(t) (lbs/in) 102 77 100 76Kt(t) (lbs/in) 169 128 167 127Km(t) (lbs/in) 254 192 251 190SUR (%) 250 250 250 250WRf(t) lbs/in 252 192 249 190Fn(f((t) (Hz) 1.748 1.748 1.739 1.739

Result InputsKt (lbs/in) 175 120 165 125Km (lbs/in) 250 175 250 185

Result OutputsKi (lbs/in) 103 71 99 75WRi (lbs/in) 102 71 99 75WRf (lbs.in) 248 175 248 185SUR (%) 243 246 252 248Fn(i) (Hz) 1.113 1.065 1.094 1.090Fn(f) (Hz) 1.735 1.670 1.735 1.717DT (in) 7.9 8.6 8.2 8.2BT (in) 8.1 7.4 7.8 7.8SH (%) 49 54 51 51

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

The BillaVista Preliminary Spring Rate Calculator - © 2008 Bill "BillaVista" Ansell, All Rights Reserved.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

NotesGreen inputs are measured. Blue inputs are subjective targetsCorner sprung weight = the weight on that corner supported by the springsActual measured total wheel travel available from full droop to full bump in ride mode with shocks installed but no springsLength of suspension-lever load arm = distance from shock mount to suspension pivot pointLength of suspension-lever effort arm = distance from wheel centre to suspension pivot pointAngle between shock axis and vertical (if shock mounted on axle) or angle between shock axis and lower link (if shock mounted on lower link), measured with angle finderPercentage of wheel travel desired to be available for droop. i.e. how much of the shock shaft is in the body as static ride height.Normally 200-300%. In a dula-rate spring setup, step-up ratio is the percentage by which the spring rate jumps at the transition from the initial spring rate to the final (main) spring rate.The natural frequency (in cyles per second) of the undamped suspension.

Generates suggested tender and main spring rates to achieve desired reults.Target initial wheel rate - the wheel rate we're aiming for with the given (blue) inputs Displacement ratio describes the relationship between wheel travel and shock travel that results from the lever between wheel and shock created by the mounting location of the shock.Angle correction factor describes the relationship between wheel travel and shock travel that results from the angle at which the shock is mounted.The IR is the ratio of wheel travel to spring/shock travel. IR combines the displacement ratio and the angle correction factor into a single ratio that relates wheel travel to shock travel by accounting for the location and angle of the shock mounting (the shock geometry).Traget initial suspension frequency - the Fn that results from the initial wheel rate.Target droop travel - assuming springs just fit between spring seats with shock fully extendedTarget bump travel - assuming springs just fit between spring seats with shock fully extendedTarget suspension height - assuming springs just fit between spring seats with shock fully extendedTarget Initial Spring Rate - based on target initial wheel rate and installation ratioTarget tender spring rate - suggested tender spring rate to achieve target initial wheel rateTarget main spring rate - suggested main spring rate based on target initial spring rate and chosen step-up ratioStep-up ratio given by the target spring rates.Target final wheel rate - the final wheel rate we're aiming for with the given (blue) inputsTraget final suspension frequency - the Fn that results from the final wheel rate.

Enter the springs you actually intend to useActual tender spring rate used - select commercially available spring closest to target KtActual main spring rate used - select commercially available spring closest to target Km

Suspension characteristics based on actual selected springs.The initial (combined) spring rate of the selected springsThe initial wheel rate achieved by the selected springs. Equal to the initial spring rate adjusted for installation ratio (DR & ACF)Final wheel rate - the wheel rate after the transition from the initial spring rate to the final spring rate. Equal to the selected main spring rate, adjusted for installation ratio (DR & ACF)Step-up ratio between the initial wheel rate and the final wheel rate.The initial suspension frequency achieved by the selected springs.The final suspension frequency achieved by the selected springs.Droop travel available with the selected springs - assuming springs just fit between spring seats with shock fully extendedBump travel available with the selected springs - assuming springs just fit between spring seats with shock fully extendedSuspension height given by use of selected springs - assuming springs just fit between spring seats with shock fully extended

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Calculator is designed to suggest preliminary spring rates on the basis of a desired suspension height or a desired suspension frequencySuggested preliminary spring rates are only a starting point - spring length, shock valving, link geometry, coilover mounting geometry, use of anti-roll bar, terrain, speed, personal preference and even seats and tires will all play a part in the ultimate expression of the vehicles ride and handling

~ Droop travel, bump travel, & suspension height figures are only valid if the springs just fit between spring seats with shock fully extended (i.e. if the springs just fit at shock travel = 0)~ Play with the corner sprung weights and observe what a huge difference they make. Accurate weights are VITAL. If you guess your weights, the calculator will guess your spring rates!!~ Adjust the shock mounting angle (alpha) and observe the results.

~ Ajust the SUR between 200-300% and observe the effects.~ Calculator may not provide spring rates commercially available in your chosen brand/length/I.D. Pick the closest available and plug into "Result Inputs" to see actual results.~ You can plug various commercially available spring rates into the "Result Inputs" section to see the range of possibilities. Particularly useful if you are choosing to buy a "range" of springs with which to test & eval.

Corner Sprung Weight Calculator ~ User entered values are in green text~ Calculated values are in black text, average in blue textLEFT FRONT RIGHT FRONT

Step 1- Calculate Installation Ratiod1 (in) 38 38d2 (in) 38 38alpha (˚) 5 5

DR 1 1ACF 0.9962 0.9962IR 0.9962 0.9962

Step 2 - Calculate Coil's Spring Rate (skip if rate is known)

Dw (wire diameter) (in) 0.64 0Di (inside diameter) (in) 2.5 2.5Dm (coil mean diameter) (in) 3.14 2.5Na (number of active coils) 14 12K (spring rate) (lbs / in) 544 0

Step 3 - Enter Spring Rate (either manufacturer's spec or calculated in step 2 above)

Main Spring - Rate (lbs/in) 350 350

Tender Spring - Rate (lbs/in) 275 275

Combined Spring Rate (lbs/in) 154 154

Step 4 - Calculate Spring Deflection at Ride Height

Main Spring - Free Length (in) 15.875 15.875

Main Spring - Length at Ride Height (in) 14.2 14.2

Main Spring - Deflection at Ride Height (in) 1.675 1.675

Tender Spring - Free Length (in) 13.875 13.875

Tender Spring - Length at Ride Height (in) 11.6 11.6

Tender Spring - Deflection at Ride Height (in) 2.275 2.275

Combined Springs - Free Length (in) 29.75 29.75

Combined Springs - Length at Ride Height (in) 25.8 25.8

Combined Springs - Deflection at Ride Height (in) 3.95 3.95

Step 5 - Calculate Corner Sprung Weight from the spring rate, the installation ratio, and the spring deflection

Corner Sprung Weight - by Main Spring (lbs) 584 584

Corner Sprung Weight - by Tender Spring (lbs) 623 623

Corner Sprung Weight - by Combined Springs (lbs) 606 606

Corner Sprung Weight - average (lbs) 604 604

~ Calculated values are in black text, average in blue textLEFT REAR RIGHT REAR

44 4444 44

2 2

1 10.9994 0.99940.9994 0.9994

0 02.5 2.52.5 2.512 12

0 0

300 300

200 200

120 120

15.875 15.875

14.3 14.3

1.575 1.575

13.875 13.875

11.6 11.6

2.275 2.275

29.75 29.75

25.9 25.9

3.85 3.85

Step 5 - Calculate Corner Sprung Weight from the spring rate, the installation ratio, and the spring deflection

472 472

455 455

462 462

463 463

Tender Spring Rates are listed across the top, Main Spring Rates are listed down the left side.The intersection of the two gives the combined (initial) spring rate.Tender Spring Rate

Main Spring Rate 80 90 100 110 120 125 130 140 150 165 175 185 200 225 250 275 300 350 37580 40 42 44 46 48 49 50 51 52 54 55 56 57 59 61 62 63 65 6690 42 45 47 50 51 52 53 55 56 58 59 61 62 64 66 68 69 72 73

100 44 47 50 52 55 56 57 58 60 62 64 65 67 69 71 73 75 78 79110 46 50 52 55 57 59 60 62 63 66 68 69 71 74 76 79 80 84 85120 48 51 55 57 60 61 62 65 67 69 71 73 75 78 81 84 86 89 91125 49 52 56 59 61 63 64 66 68 71 73 75 77 80 83 86 88 92 94130 50 53 57 60 62 64 65 67 70 73 75 76 79 82 86 88 91 95 97140 51 55 58 62 65 66 67 70 72 76 78 80 82 86 90 93 95 100 102150 52 56 60 63 67 68 70 72 75 79 81 83 86 90 94 97 100 105 107165 54 58 62 66 69 71 73 76 79 83 85 87 90 95 99 103 106 112 115175 55 59 64 68 71 73 75 78 81 85 88 90 93 98 103 107 111 117 119185 56 61 65 69 73 75 76 80 83 87 90 93 96 102 106 111 114 121 124200 57 62 67 71 75 77 79 82 86 90 93 96 100 106 111 116 120 127 130225 59 64 69 74 78 80 82 86 90 95 98 102 106 113 118 124 129 137 141250 61 66 71 76 81 83 86 90 94 99 103 106 111 118 125 131 136 146 150275 62 68 73 79 84 86 88 93 97 103 107 111 116 124 131 138 143 154 159300 63 69 75 80 86 88 91 95 100 106 111 114 120 129 136 143 150 162 167350 65 72 78 84 89 92 95 100 105 112 117 121 127 137 146 154 162 175 181375 66 73 79 85 91 94 97 102 107 115 119 124 130 141 150 159 167 181 188400 67 73 80 86 92 95 98 104 109 117 122 126 133 144 154 163 171 187 194425 67 74 81 87 94 97 100 105 111 119 124 129 136 147 157 167 176 192 199450 68 75 82 88 95 98 101 107 113 121 126 131 138 150 161 171 180 197 205475 68 76 83 89 96 99 102 108 114 122 128 133 141 153 164 174 184 202 210500 69 76 83 90 97 100 103 109 115 124 130 135 143 155 167 177 188 206 214525 69 77 84 91 98 101 104 111 117 126 131 137 145 158 169 180 191 210 219550 70 77 85 92 99 102 105 112 118 127 133 138 147 160 172 183 194 214 223600 71 78 86 93 100 103 107 114 120 129 135 141 150 164 176 189 200 221 231625 71 79 86 94 101 104 108 114 121 131 137 143 152 165 179 191 203 224 234650 71 79 87 94 101 105 108 115 122 132 138 144 153 167 181 193 205 228 238700 72 80 88 95 102 106 110 117 124 134 140 146 156 170 184 197 210 233 244725 72 80 88 96 103 107 110 117 124 134 141 147 157 172 186 199 212 236 247750 72 80 88 96 103 107 111 118 125 135 142 148 158 173 188 201 214 239 250800 73 81 89 97 104 108 112 119 126 137 144 150 160 176 190 205 218 243 255

Tender Spring Rates are listed across the top, Main Spring Rates are listed down the left side.

400 425 450 475 500 525 550 600 625 650 700 725 750 80067 67 68 68 69 69 70 71 71 71 72 72 72 7373 74 75 76 76 77 77 78 79 79 80 80 80 8180 81 82 83 83 84 85 86 86 87 88 88 88 8986 87 88 89 90 91 92 93 94 94 95 96 96 9792 94 95 96 97 98 99 100 101 101 102 103 103 10495 97 98 99 100 101 102 103 104 105 106 107 107 10898 100 101 102 103 104 105 107 108 108 110 110 111 112

104 105 107 108 109 111 112 114 114 115 117 117 118 119109 111 113 114 115 117 118 120 121 122 124 124 125 126117 119 121 122 124 126 127 129 131 132 134 134 135 137122 124 126 128 130 131 133 135 137 138 140 141 142 144126 129 131 133 135 137 138 141 143 144 146 147 148 150133 136 138 141 143 145 147 150 152 153 156 157 158 160144 147 150 153 155 158 160 164 165 167 170 172 173 176154 157 161 164 167 169 172 176 179 181 184 186 188 190163 167 171 174 177 180 183 189 191 193 197 199 201 205171 176 180 184 188 191 194 200 203 205 210 212 214 218187 192 197 202 206 210 214 221 224 228 233 236 239 243194 199 205 210 214 219 223 231 234 238 244 247 250 255200 206 212 217 222 227 232 240 244 248 255 258 261 267206 213 219 224 230 235 240 249 253 257 264 268 271 278212 219 225 231 237 242 248 257 262 266 274 278 281 288217 224 231 238 244 249 255 265 270 274 283 287 291 298222 230 237 244 250 256 262 273 278 283 292 296 300 308227 235 242 249 256 263 269 280 285 290 300 305 309 317232 240 248 255 262 269 275 287 293 298 308 313 317 326240 249 257 265 273 280 287 300 306 312 323 328 333 343244 253 262 270 278 285 293 306 313 319 330 336 341 351248 257 266 274 283 290 298 312 319 325 337 343 348 359255 264 274 283 292 300 308 323 330 337 350 356 362 373258 268 278 287 296 305 313 328 336 343 356 363 369 380261 271 281 291 300 309 317 333 341 348 362 369 375 387267 278 288 298 308 317 326 343 351 359 373 380 387 400

Anti-Pitching Front to Rear Suspension Frequency Balance Calculator

Use this simple calculator to determine by how much the front to rear suspension frequencies should differ to combat pitching at a given speed.~ User entered values are in green text.~ Calculated values are in black text.There are multiple columns for data input so you can easily calculate and compare the results for different speeds and/or wheelbasesMethod 1 - I know what I want my front suspension frequency to be - what should the rear be?Wheelbase (in) 105 105 105 105Speed (mph) 20 40 60 80Fn(front) (Hz) 1.107 1.107 1.107 1.107

Twb (s) 0.2982 0.1491 0.0994 0.0746Pf (s) 0.9033 0.9033 0.9033 0.9033Pr (s) 0.6051 0.7542 0.8039 0.8288

Fn(rear) (Hz) 1.6525 1.3258 1.2439 1.2066

% Difference 49.3% 19.8% 12.4% 9.0%

Method 2 - I know what I want my rear suspension frequency to be - what should the front be?Wheelbase (in) 110 110 110 110Speed (mph) 10 30 60 90Fn(rear) (Hz) 1.213 1.213 1.213 1.213

Twb (s) 0.6248 0.2083 0.1041 0.0694Pr (s) 0.8244 0.8244 0.8244 0.8244Pf (s) 1.4492 1.0327 0.9285 0.8938

Fn(front) (Hz) 0.6900 0.9684 1.0770 1.1188

% Difference 75.8% 25.3% 12.6% 8.4%

Use this simple calculator to determine by how much the front to rear suspension frequencies should differ to combat pitching at a given speed.

There are multiple columns for data input so you can easily calculate and compare the results for different speeds and/or wheelbases

85 105 12560 60 60

1.107 1.107 1.107

0.0805 0.0994 0.11830.9033 0.9033 0.90330.8229 0.8039 0.7850

1.2153 1.2439 1.2739

9.8% 12.4% 15.1%

110 110 110120 200 300

1.213 1.213 1.213

0.0521 0.0312 0.02080.8244 0.8244 0.82440.8765 0.8556 0.8452

1.1409 1.1687 1.1831

6.3% 3.8% 2.5%

Equations VariablesDm = Di + Dw Suspensionk = 11,250,000 * (Dw)^4 / 8 * Na * (Dm)^3 RH Ride Heightk = load / deflection (or force / deflection) SH Suspension HeightFn = 3.13/sqrt(x) WT Wheel TravelKi = (Km * Kt) / (Km + Kt) ST Shock / Spring TravelKf = KmCSW = CW – CUW DT Droop TravelSUR = (Kf / Ki) *100% BT Bump Travel

F1*d1 = F2*d2 WR Wheel rateF1 = (F2 * d2) / d1. Wri Initial wheel rateMA = d2/d1. Wrf Final wheel rateDR = d1/d2ACF = cos(alpha) CW Corner WeightIR = DR * ACF CSW Corner Sprung Weight

CUW Corner Unsprung WeightST = WT * IRWT = ST / IR IR Installation ratioIR = ST / WTIR = DR * ACF = (d1/d2) * cos(alpha) Fn Suspension frequencyWR = k * IR^2WRi = Ki * (IR)^2 LeversWRf = Km * (IR)^2 d1 length of the load arm

d2 length of the effort armSH = Fn / IR F1 Load

F2 EffortWR = CSW / (WT * SH %) MA Mechanical advantageWR = (CSW*(2PI*Fn)^2)/386.088 DR Displacement Ratio

AnglesFn = sqrt ((386.088 * WR ) / CSW ) / 2pi ACF Angle correction factor

alpha Angle alphaFw=Fs*IRFs=k*STFw=WR*WT

Twb = (0.0568 * WB) / SP= 1 / FnPr = Pf - TwbPf = Pr + TwbFn = 1 / P

The Big Five

IR = Ds / DwFw = Fs * IRDw = Ds / IRFs = k * DsFw = WR * Dw

SpringsDi Inside DiameterDw Wire DiameterDm Mean DiameterNa Number of Active Coilsk Spring RateLo Free LengthLc Block HeightSc Travel (max defection) Fc Force Limit

Ki Initial Spring Rate (of combined springs)Km Spring Rate of Main SpringKt Spring Rate of Tender SpringKf Final Spring rate

SUR Step-up Ratio

Force

Fw Wheel ForceFs Spring Force

Anti-Pitching

Twb Time to travel wheelbase (seconds)WB Wheelbase (in)S Speed (mph)P Period (seconds)Pf Period of front suspension (seconds)Pr Period of rear suspension (seconds)