cuting the springs

i think some people are still missing the point, it is £60 for some springs, and cutting them is a bodge, even if it works perfectly its still bodging it.

bodging things breeds bad habbits, if you bodge your springs then what else will you bodge? running the car on 3 wheel nuts per wheel? or maybe you don't NEED to tigten the nut on the steering wheel because it still held on by the spline....

if you don't service a car on the day it hits its 10k service, will it stop running and break down? no it will keep going but that doesn't mean you don't have to service it.

thats what i have a problem with, i don't care if cutting springs is safe and works fine, its the wrong way to go about doing car mechanics.
 
the lenth of a spring doesnt alter the stiffness FACT i can compress a spring the same amount as if it was it half FACT ive done it loads of times
 
jowley said:
the lenth of a spring doesnt alter the stiffness FACT i can compress a spring the same amount as if it was it half FACT ive done it loads of times
Click to expand...
when the springs are fitted to the leg, they are the same length :) (but one has 8 coils and the other has 5)
 
frank said:
when the springs are fitted to the leg, they are the same length :) (but one has 8 coils and the other has 5)
Click to expand...

Yes and that WOULD affect stiffness however cutting a spring down to half the length of the original would still be the same stiffness only shorter
 
ollyc98 said:
Yes and that WOULD affect stiffness however cutting a spring down to half the length of the original would still be the same stiffness only shorter
Click to expand...

so, if i was to cut 2 of the 8 coils off, and fit it back onto the leg (without the need for compressors) the stock 6 coil spring would be stiffer yes ? :)
 
NeX said:
i think some people are still missing the point, it is £60 for some springs, and cutting them is a bodge, even if it works perfectly its still bodging it.

bodging things breeds bad habbits, if you bodge your springs then what else will you bodge? running the car on 3 wheel nuts per wheel? or maybe you don't NEED to tigten the nut on the steering wheel because it still held on by the spline....

if you don't service a car on the day it hits its 10k service, will it stop running and break down? no it will keep going but that doesn't mean you don't have to service it.

thats what i have a problem with, i don't care if cutting springs is safe and works fine, its the wrong way to go about doing car mechanics.
Click to expand...
um ive had three wheel nuts in my wheel for about a year now check them every week for tightness and they are allways fine lol!the hole has been threadded i just havent got round to buying a tap for the hole!lol

lmao!
 
nissanmicrak12 said:
um ive had three wheel nuts in my wheel for about a year now check them every week for tightness and they are allways fine lol!the hole has been threadded i just havent got round to buying a tap for the hole!lol

lmao!
Click to expand...

lol ok then i wasn't expecting that lol, but i would advice you get that sorted, it will no doubt add to un even tyre wear or un even braking, and could even be claimed as the cause of a crash if you had a crash and the insurance checked your car to see if it was road worthy
 
never mind!lmao what i would do if i had a crash is put another nut in and make it look like it was ok....lmao tyre wear is fine and breaking is spot on , so no probs there lol :p

its not loose one bit but i do have to remember to go to cromwell tools to get one i get discount there lol!
 
jowley said:
no the lenth doesnt make any diference to the stiffness its the thickness that makes it stiffer
Click to expand...

Have you read this page?

http://www.eatonsprings.com/atqCuttingCoilSpringsCalculations.htm

If you take a coil spring and change nothing but reduce the number of active coils it's spring rate will have risen. If you apply a load to the spring it will be deflected less than it was at its original length.

Imagine putting a bag of cement in a car boot.
First a car with stock springs, measure the ride height, put the cement in the boot and measure again. This will give you a measurement that shows how much the spring was deflected by the load.

Now try it with the same spring but with an active coil removed, measure the ride height, put the cement in the boot and measure again. The difference measured will be less. The same load has deflected the spring less, therefore the second spring is stiffer.

In the second test the car will have started lower, so you have to measure from where it starts, not the original start point.

If you are not happy to accept this, find something elsewhere on the net that supports your arguement that cutting the coils off of a spring does not make them stiffer.

ollyc98 said:
Yes and that WOULD affect stiffness however cutting a spring down to half the length of the original would still be the same stiffness only shorter
Click to expand...

Yeah the spring with less coils, wound less tightly so that it was the same length as the spring with more coils would be stiffer, given that the diameter of the wire and the coils remained the same.

If the spring with less coils was wound as tightly as the spring with more coils it would both be shorter and stiffer.

There is no variable in the calculation to find spring rate that is "how tightly the coils are wound" or "what is the start lenght of the spring"


This is a spring rate calculater provided elsewhere on the web, try it and only vary the number of active coils.

http://www.ajdesigner.com/phpspringrate/spring_rate_equation.php

jowley said:
no the lenth doesnt make any diference to the stiffness its the thickness that makes it stiffer
Click to expand...

That is just one of the variables that changes the stiffness of a spring.
 
Right well as I have got to replace my springs all round anyway and happen to have a tonne of sand handy I will test your theory, but not until payday cos I can't find my spring compressors and I'm not doing it with ratchet straps again
 
ollyc98 said:
Right well as I have got to replace my springs all round anyway and happen to have a tonne of sand handy I will test your theory, but not until payday cos I can't find my spring compressors and I'm not doing it with ratchet straps again
Click to expand...

It's not just my theory though is it, it appears all over the interweb, never mind the number of textbooks, physics and engineering classrooms all over the world that it is taught in.
 
markbognor said:
Have you read this page?

http://www.eatonsprings.com/atqCuttingCoilSpringsCalculations.htm

If you take a coil spring and change nothing but reduce the number of active coils it's spring rate will have risen. If you apply a load to the spring it will be deflected less than it was at its original length.

Imagine putting a bag of cement in a car boot.
First a car with stock springs, measure the ride height, put the cement in the boot and measure again. This will give you a measurement that shows how much the spring was deflected by the load.

Now try it with the same spring but with an active coil removed, measure the ride height, put the cement in the boot and measure again. The difference measured will be less. The same load has deflected the spring less, therefore the second spring is stiffer.

In the second test the car will have started lower, so you have to measure from where it starts, not the original start point.

If you are not happy to accept this, find something elsewhere on the net that supports your arguement that cutting the coils off of a spring does not make them stiffer.



Yeah the spring with less coils, wound less tightly so that it was the same length as the spring with more coils would be stiffer, given that the diameter of the wire and the coils remained the same.

If the spring with less coils was wound as tightly as the spring with more coils it would both be shorter and stiffer.

There is no variable in the calculation to find spring rate that is "how tightly the coils are wound" or "what is the start lenght of the spring"


This is a spring rate calculater provided elsewhere on the web, try it and only vary the number of active coils.

http://www.ajdesigner.com/phpspringrate/spring_rate_equation.php



That is just one of the variables that changes the stiffness of a spring.
Click to expand...

i have done this at work i can compress the spring the same weather its ful or in half the same the reason it seems stiffer is because there are les coils so u use the same amount of force on both and measure inbetween two coil the same but overhall the measurement would be different
 
Ah i think i see what you are getting at, if you take the spring with less coils and apply the same load, the coils will have compressed the same ammount as the spring with more coils.

So for each individual coil the compression ammount for the load is the same.

Is this why you are arguing that the spring stays the same stiffness, its just shorter?

So if you take a spring with 8 coils, apply a load and each coil compresses 10mm, the total compression is 80mm.

Say you then take the spring with less coils, because two full coils have been cut off, that has 6 coils and apply the same load, each coil would as you say compress 10mm. This would give a total compression of 60mm.

With the same load the 8 coil spring will compress 80mm, the shorter six coil spring will compress 60mm.

To get the shorter spring to compress the same ammount as the longer spring a greater load would need to be applied. Meaning that the spring with less coils is stiffer.
 
yes the 6 coil spring is stiffer because you have less coils and you have to bend each one a bit further, whereas the 8 coil spring (preloaded into the leg to the same 11" length) has more coils so you dont have to bend each coil so much (making it softer) :)
 
Yeah, but the rate at which the spring gets stiffer is greater for a spring with less coils, to compress each spring the same ammount you have to apply proportionally more load. So the spring with less coils is stiffer!

Which means that if you take a spring with 8 coils, and cut 2 off, it becomes a stiffer spring because the ammount of load that has to be applied to get the same deflection as before has increased!
 
no my lowering springs which are harder have the same amount of coils but the spring is thicker and has a different spacing in bteween coils
 
jowley said:
no my lowering springs which are harder have the same amount of coils but the spring is thicker and has a different spacing in bteween coils
Click to expand...

jowley, are yours the type with a few tightly wound coils on each end, and the middle coils wider spaced ?:)
 
markbognor said:
Ah i think i see what you are getting at, if you take the spring with less coils and apply the same load, the coils will have compressed the same ammount as the spring with more coils.

So for each individual coil the compression ammount for the load is the same.

Is this why you are arguing that the spring stays the same stiffness, its just shorter?

So if you take a spring with 8 coils, apply a load and each coil compresses 10mm, the total compression is 80mm.

Say you then take the spring with less coils, because two full coils have been cut off, that has 6 coils and apply the same load, each coil would as you say compress 10mm. This would give a total compression of 60mm.

With the same load the 8 coil spring will compress 80mm, the shorter six coil spring will compress 60mm.

To get the shorter spring to compress the same ammount as the longer spring a greater load would need to be applied. Meaning that the spring with less coils is stiffer.
Click to expand...

Well done you've just put it into words I can understand, I guess I was wrong sorry lol
 
ollyc98 said:
Well done you've just put it into words I can understand, I guess I was wrong sorry lol
Click to expand...

Hey no need to appologise for anything (Y)

jowley said:
no my lowering springs which are harder have the same amount of coils but the spring is thicker and has a different spacing in bteween coils
Click to expand...

You probably have progressive springs then, some work by having a few coils closer together, that then close up completely under a heavy load, reducing the ammount of active coils and making the spring stiffer. It doesn't change the fact that as the active number of coils are reduced the spring gets stiffer.

If you keep the number of coils and the coil diameter the same, but use a thicker gauge wire, you will be making a stiffer spring. But the wire gauge is not the only variable that can be changed to alter the spring properties. The number of coils, and the diameter of the coils can also be changed to have the effect of making the spring stiffer or softer. Obviously once a spring has been made the only one of these that can be changed is the number of active coils.
 
and still the battle raged long into the night. it was a vicious, unforgiving battle, many innocent minutes were lost and many keyboards bashed, waiting for that one knight in shining armour, the keyboard warrior that was prophesised would SAVE THE INTERNET!!!!!



But he never came ¬_¬
 
frank said:
jowley, are yours the type with a few tightly wound coils on each end, and the middle coils wider spaced ?:)
Click to expand...

yeh there spax ones.



Quote:
Originally Posted by ollyc98
Well done you've just put it into words I can understand, I guess I was wrong sorry lol

Hey no need to appologise for anything


Quote:
Originally Posted by jowley
no my lowering springs which are harder have the same amount of coils but the spring is thicker and has a different spacing in bteween coils

You probably have progressive springs then, some work by having a few coils closer together, that then close up completely under a heavy load, reducing the ammount of active coils and making the spring stiffer. It doesn't change the fact that as the active number of coils are reduced the spring gets stiffer.

If you keep the number of coils and the coil diameter the same, but use a thicker gauge wire, you will be making a stiffer spring. But the wire gauge is not the only variable that can be changed to alter the spring properties. The number of coils, and the diameter of the coils can also be changed to have the effect of making the spring stiffer or softer. Obviously once a spring has been made the only one of these that can be changed is the number of active coils

but a chopped one and a normal one is still the same stiffness all ur doing is getting to it slighty quicker eg u put a heavy load in the back of your car on normal springs it get stiffer
 
not correct realy.

a standard spring under load will be shorter overall than a cut spring without load.

but the cut spring is stiffer.

you are getting confused between spring rate and Preload, something that children on "full sus" bikes tend to confuse. they wind the back spring up as tight as it will go to make it stiffer..... it isnt stiffer it has just had its initial load applied and is now under its "spring rate load" the spring will still act in the same way weather under load or not.

thats why when you get two fat chicks in the back of your car the suspension still bottoms out. its not stiffer, just shorter. but if you cut the springs on the back so that the inactive coils were removed the spring rate will go up and you can now have the two fat chicks in the back with a lesser chance of rubing.

thats why coilovers have two collars on them to adjust the height of a spring rather than just wind it up, making the spring more compressed and taking out its initial caracteristics.


its complicated.
 

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