Cutting Suspension Springs

aswearing

Torque Master
Points
72
Location
Doncaster
Car
Micra 160sr
Now I want to make it VERY clear, I DO NOT condone this whatsoever, I believe that cutting suspension springs instead of buying new lowering springs is both dangerous and wreckless, springs were designed with a specific load bearing weight in mind, and taking a 'couple of coils' off of this would impair their ability to work effectively.

I mention this as it has be mentioned and recommended on another forum, and I had to say my bit. Would like extra feedback here also.
 
To a point, I would use spacers on my rear wheels because they sit too far into the body. But they would ALWAYS be coupled with longer wheel nuts to compensate. Not doing that is asking for a situation where your wheel will over take you...
 
I have no problem using wheel spacers (as long as they'r hubcentric) or cutting springs, same old chesnut keeps popping up. how do you think people used to do things before the availability of aftermarket springs. I have even cut pigtail springs and just made a new mounting plate.
 
I have no problem using wheel spacers (as long as they'r hubcentric) or cutting springs, same old chesnut keeps popping up. how do you think people used to do things before the availability of aftermarket springs. I have even cut pigtail springs and just made a new mounting plate.

That's a good point about cutting the springs before aftermarket started to appear!
@ aswearing, as a safer alternative, in my eyes anyway! Is there not a clamping arrangement now, that goes inside the spring and can be wound down to limit the springs height? Fairly sure I have seen one of these on my travels through a car mag somewhere!
 
That's a good point about cutting the springs before aftermarket started to appear!
@ aswearing, as a safer alternative, in my eyes anyway! Is there not a clamping arrangement now, that goes inside the spring and can be wound down to limit the springs height? Fairly sure I have seen one of these on my travels through a car mag somewhere!

Yep my mate had them on his camper but after a couple of months of the suspension knocking. he opted for proper lowering springs;)
 
How would your insurance company respond to this though? If you were describing the modification as it isnt factory standard how would you describe it, as aftermarket springs from a reputable company that offer a one year warranty and improve handling for better road safety will sound better surely?

What about VOSA checks? I don't agree that people promote it so much when aftermarket springs are readily available and at such a low price.
 
There are many safety and performance reasons for NOT cutting your standard springs. This mod should be left to the experts - the ones that think overstretching tyres is also a safe and good performance idea.
 
There are many safety and performance reasons for NOT cutting your standard springs. This mod should be left to the experts - the ones that think overstretching tyres is also a safe and good performance idea.

OG, I also seem to remember back in the day, of springs being heated up with some weights applied to lower them!! or am I thinking about something else here? :blink:
 
OG, I also seem to remember back in the day, of springs being heated up with some weights applied to lower them!! or am I thinking about something else here? :blink:

Nope, I remember idiots doing that as well! Ideal way to induce spring bind and increase the chances of the spring cracking and breaking.

Leave spring modifications to those who know what they are doing.
 
The cheap(ish) answer if you want slightly lowered ride height and don't want to upset the general ride quality is to use progressively wound springs. It's the same length of wire as a stock spring but the coils are wound closer together at one end of the spring.

So the suspension firms up progressively as the spring compression increases. Coupled with a set of stiffer dampers this is a good way to sharpen up the handling of any car which uses coil springs.

Much better than stiffer ARBs in my opinion. All ARBs do is to compromise the left/right suspension independence.
 
Only reason I mentioned this was due to it being mention on another (unnamed) forum, and the replies promoting DIY cutting springs was a shock. Especially in this day and age :blink:
 
why would anyone in there right mind cut there own spring :? you can get a set of after markets one for about £70

wheel spacers are fine, just dont get those cheap crappy ones that dont fit properly,

Eiback hubcentric are car specific and track tested ;)
 
Nice for our MOT man to give us a tip to aviod such things :lol:

I'm just messing with you mate,
To be fair to you, if you spent enough time to inspect to the enth degree you'd never get an MOT done!!!

I thought about getting some wheel spacers, any brand in particular to look at?
 
Hi all, first post.
Can anyone tell me exactly why it is dangerous to cut a coil spring to lower a car? As I intend doing it next week, but I am open to persuasion. To date no-one has been able to give a definative answer The aftermarket springs I have looked at have all been cut to a given length. I am talking about the standard coil spring here, where the cup or spring seat is shaped to suit a cut spring. MOT is irrelevant, as it is for a race car. BTW if you think about it, not one car on the GP grid yesterday would pass an MOT!
 
Hi all, first post.
Can anyone tell me exactly why it is dangerous to cut a coil spring to lower a car? As I intend doing it next week, but I am open to persuasion. To date no-one has been able to give a definative answer The aftermarket springs I have looked at have all been cut to a given length. I am talking about the standard coil spring here, where the cup or spring seat is shaped to suit a cut spring. MOT is irrelevant, as it is for a race car. BTW if you think about it, not one car on the GP grid yesterday would pass an MOT!

Greetings and Welcome! ;)

I am sure that anytime soon, someone will be along to explain in laymans terms why these spring reducing techniques are best left alone and to be done by true experts only. Although if you reread some of the past posts here, I think it explains it quite clearly enough, for me anyway! :)
 
The way I see it is: the spring requires a seat for it to press against in both directions in the z axis. If the typical ground flat return is cut off the spring then you are left with a helical section with no ground surface plane. Thus no datum face for the load to bear against. In another word a flat ground spring seat has maximum surface area contact where a cut down one only has point contact. In this instance under load I would expect the spring to want to escape the mounting as it now has leverage load as well due to the open helix. Remember that the distance between each spring seat is made to suit the travel and geometry set as such until full load is found, it is not a linear action as the suspension follows a radii as defined by the suspension arms, links or wishbone lengths. Lowered springs need lowered platforms otherwise the springs may come slack when getting loose on any surface.

Before custom springs were the norm people did cut them down, ground the last spring as flat as they dared and also cut down the shock pistons and re-cut the threads. Springs do move around in this instance as they are not located concentrically.

:blink: I'll read this again later..............
 
No, a GP car would never pass an MOT, but it's not supposed to because it will never be used on the road, however I can guarantee that they have specially designed springs that aren't simply cut down one they found in the back of the work shop, the reason for not cutting springs is because it's dangerous for reasons explained before and you are shortening the spring while the spring rate remains the same thus your car will more likely bottom out on the bump stops when the body rolls in the corner and affectively giving you no suspension, the reason for going stiffer and lower is so it limits the spring travel when the suspension is under load and it wont hit the bump stops,

If you are going to take your race car seriously then you want a proper setup not a botched affair
 
Anyone who cuts coil springs these days should not be allowed anywhere near a car and all of his tools should be confiscated!! :)

If you are even considering cutting springs for your race car, what other short cuts (pun intended) are you planning?

Save up and buy a set of springs designed specifically for your car and its intended use. It will handle much better and it will be a lot safer for both you and other drivers.

Rant over.

PS. I think this explains it pretty well:

http://craig.backfire.ca/pages/autos/cutting-springs
 
Last edited:
Anyone who cuts coil springs these days should not be allowed anywhere near a car and all of his tools should be confiscated!! :)

If you are even considering cutting springs for your race car, what other short cuts (pun intended) are you planning?

Save up and buy a set of springs designed specifically for your car and its intended use. It will handle much better and it will be a lot safer for both you and other drivers.

Rant over.

PS. I think this explains it pretty well:

http://craig.backfire.ca/pages/autos/cutting-springs

Nice link OG, that should do the trick. However a bit early in the morning for calcs! :bigsmile:
 
Anyone who cuts coil springs these days should not be allowed anywhere near a car and all of his tools should be confiscated!! :)

If you are even considering cutting springs for your race car, what other short cuts (pun intended) are you planning?

Save up and buy a set of springs designed specifically for your car and its intended use. It will handle much better and it will be a lot safer for both you and other drivers.

Rant over.

PS. I think this explains it pretty well:

http://craig.backfire.ca/pages/autos/cutting-springs
Time to bump this thread up for newer members to read it in case any of them were thinking of doing this.
 

Similar threads


Please watch this on my YouTube channel & Subscribe.


Back
Top