[stocker]

Hi fellow auszookers

Has anyone had trouble with the Calmini rear springs sagging.? And just not carrying any sought of weight... Although I've had the kit over a year now I don't think I've done more than a thousand km's... And I've not had it laden with any sought of load and it has literally just sat in the driveway...

I'm definitely not impressed... I would like to know if this is a common problem?

What would be a suitable replacement?

[Chop]

Mine never sagged, and i had a trailer on it nearly every day of the week and sometimes alot of weight in the back. But i did have trouble with them bottoming out out coz theyre way to soft with only a slight load in the back. IMO theyre meant for a swb and not rated for a lwb.

[stocker]

Thanks chop. Mine have sagged approx 40mm.

[atari4x4]

yeah i'm sure the whole kit was designed around the SWB's... i am very interested in suggestions for replacement springs.

i want height, load carrying & flex. was thinking about trying to chase up the rear springs out of their GV 2.5" kit seeing i'm running the fronts, but not sure if I can get them individually.

[atari4x4]

stocker wrote:

Thanks chop. Mine have sagged approx 40mm.

sagged or settled from the original install height... what is your before lift measurement & after lift measurement & current measurement?

mine initially lifted the rear something like 4.5" & settled to just over 3"

[Gwagensteve]

atari4x4 wrote:

sagged or settled from the original install height... what is your before lift measurement & after lift measurement & current measurement?

mine initially lifted the rear something like 4.5" & settled to just over 3"

Due to the lack of bumpstop spacers in the calmini kit, the binding of the spring on full compression will result in sag. I think this is what Calmini call "settling"

I'd be interested if the end result was <3" of lift. I've fitted the same, old Calmini kit to a number of different cars over the years and the result has always been adequate lift. I haven't fitted a new kit from scratch so I can't comment on how far it "settled"

Steve.

[atari4x4]

even with bumpstop spacers mine settled from the 4"+ it had on install, down to over 3".

[joeblow]

Gwagensteve wrote:

Due to the lack of bumpstop spacers in the calmini kit, the binding of the spring on full compression will result in sag.

No it won't. 'Binding' won't cause sag. A coil spring will go solid when it bottoms out, and thats it. When it does it will usually fatigue mounts etc. The coil will sag due to poor design, spring rate and material it's made from and various other factors.

[Gwagensteve]

Quote:

Stress Consideration in Spring Design
Many times, because of the long stroke requirements for certain rates of racing springs, material strength must be sacrificed to achieve significant stroke. Couple this with the fact that the ideal wire diameter is not always made and you can see why some springs have a real potential to take a set. We have seen some brands of springs lose as much as 15/16" of free height during normal operation. To eliminate any set from occurring at the race track, it is good manufacturing policy to pre-set (press to solid height) all racing springs during their manufacture.

If done correctly, pre-setting will generally eliminate any potential for additional set, even when springs are designed with smaller than ideal wire. Shot-peening will further enhance a spring's durability. It should be pointed out that all Afcoils are pre-set and shot-peened during manufacture.

What if a Spring "Sets"?
When a spring takes a set it will normally stabilize at its new height. The rate effectively remains the same since no appreciable changes have been made to any of the three factors that determine the spring's rate. Other than creating a need to readjust the chassis (to restore the original set-up and ride heights) the spring should provide satisfactory performance. It is not uncommon for even well designed and properly manufactured springs to settle up to 1% of their free height. It needs to be pointed out, however, that in cases where a poorly designed spring is subject to extreme over-stressing, the spring's height may not stabilize. The spring may continue to change height (both shortening and lengthening) as the spring is worked. As a result, the set-up on the race car changes every time the spring's height changes. This can cause major chassis tuning headaches!

Monitor your Springs:
We recommend that you monitor the free heights of your springs on a regular basis. This is so important that some Indycar teams measure their springs' heights to the thousandth of an inch. Be sure to always measure height at the same point on the end coils(mark your springs to indicate the measuring point). You should suspect that a spring is setting whenever wheel weights continually change. Under no circumstances should springs be used that change more than 2% in height or do not stabilize in height. AFCOILS are guaranteed to maintain their free heights to within 2% forever!

At the least you should inspect all springs for free height changes after racing on a very rough track or if your race car was involved in a wreck. By now, you should realize there is much more chance for a spring to change its height than its rate. Consequently, you should spend your time monitoring your springs' free heights and not their rates!

What is Coil Bind?
Coil bind occurs whenever a spring is compressed and one or more of the springs active coils contacts another coil. The rate of the spring increases whenever a coil binds since the bound coil or coils are no longer active(this changes one of the three rate-determining factors). Of course, handling is affected whenever a coil binds. If the spring is compressed to solid height (all coils touching) during suspension movement, the suspension will cease to work. You can, and should, check for evidence of coil bind by examining the finish between the active coils. If any coils have bound the finish between them will show contact marks that appear as though they were drawn with a lead pencil. Normally any spring that is binding should be replaced with a taller spring. Be aware, however, there are racing springs on the market that are built with wire that is heavier than what's needed. These springs will coil bind before others that are built with the proper size wire.

Under very extreme conditions, coil binding can cause a spring to unwind slightly. This can cause the mean diameter of the spring to increase and reduce rate of the spring. You should realize that the potential for coil bind is increased whenever short springs are used. Always match the spring to the job.

I'm not sure how much experience you have with the calmini kit Joe, but the coils bind like a mofo, and Calmini advise that you have to go out and beat on the suspension in order to get it to "settle"

Join the dots.

Steve.

[joeblow]

Do they mean settle as in 'seating correctly'...or in relation to ride height?

If that is the case I would be worried.

If a spring is made correctly, and from good quality materials and correct process it should not sag (settle) too much, even if it's going 'solid' a lot of the time (this will break you car...not the spring).

Springs do have a certain amount of memory. If you have a long light rate spring for it's flex, and you place a heavy constant load on it it will sag somewhat. More noticable in cheaper materials. Same applies for parking it flexed up for a long period of time. General 4 wheeling and articulation should not affect a spring a great deal.

[atari4x4]

that would be option "B" joe, i wonder if their springs come unscragged as a measure of cost cutting?

[Gwagensteve]

No, it's settle as in ride height..... straight from Calmini's instructions. I don't think they are scragged AND they bind in normal operation.

Steve.

[twitchy]

Just read the bit from calmini & a spring that "unwound slightly" would have to be bound hard enough for the car to break.
As for binding, variable rate springs are designed to do just that, progressively bind which changes the spring rate & isn't a foreign thing to spring manufacturers. Suspension gear should settle in very quickly & a lot of people fully tighten the suspension components before it is put on the ground which will give you an artificial ride height for a day or 2.

[stocker]

twitchy wrote:

Just read the bit from calmini & a spring that "unwound slightly" would have to be bound hard enough for the car to break.
As for binding, variable rate springs are designed to do just that, progressively bind which changes the spring rate & isn't a foreign thing to spring manufacturers. Suspension gear should settle in very quickly & a lot of people fully tighten the suspension components before it is put on the ground which will give you an artificial ride height for a day or 2.

I've had the kit in for almost a year now, and its only in the last 3 months that i've really noticed that the ride height has changed. a day or two i could understand, it was ALOT taller for a day or two when we first put the kit in, but it is noticeably shorter now.

Could i ask someone with the same setup ie: calmini lift and 2" body lift, just to measure the height from flat level ground to the bottom of the chassis infront of the rear tyre, and then the same at the front. It would be muchly appreciated.

[zukmeista]

That measurement is not relevant without taking into account tyre size.

[atari4x4]

stocker if you measure eyebrow heights, you don't have to worry about finding someone with the same sized tyres.

[stocker]

atari4x4 wrote:

stocker if you measure eyebrow heights, you don't have to worry about finding someone with the same sized tyres.

Thanks, didn't think of that, i am running a 31" tyre, that actually measures 31 inches....
however measuring the eyebrow heights is a good idea also, thanks atari!

[Gwagensteve]

twitchy wrote:

Just read the bit from calmini & a spring that "unwound slightly" would have to be bound hard enough for the car to break.
As for binding, variable rate springs are designed to do just that, progressively bind which changes the spring rate & isn't a foreign thing to spring manufacturers. Suspension gear should settle in very quickly & a lot of people fully tighten the suspension components before it is put on the ground which will give you an artificial ride height for a day or 2.

I do understand your point here Twitchy, but the binding inherent in the calmini spring design isn't a perfectly aligned "hard bottoming" type of thing like a progressive spring observes* Due to the misalignment of the top and bottom coil towers, the coils want to try and slip past each other a bit. This is, as far as I am aware, outside of the design parameters for a spring. The effect IMHO will be similar to overcompressing a leaf spring - lost rate and height.

Steve.


* Whilst a progressive spring does have some coils in bind at ride height, the coil itself isn't being overstressed because it still has free coils. Squishing a spring up so the coils start to slide past each other because the whole spring is bound and misaligned is a different thing altogether. This isn't a myth, I've pulled Calmini rear springs out and seen where the powdercoat as some away through binding.

[Chop]

I slapped the crap out of my rear calmini in my old lwb, when it was full of camping gear. They haven't sagged, theyre just too soft for the lwb.
You can see even now at Britvits place it isn't sagging in the rear.

[britvit]

I measured the LWB (chop's old one) with the calmini springs but no body lift. The 'eyebrow' height is 55cm. This is with nothing in the car and no back seat.

[stocker]

britvit wrote:

I measured the LWB (chop's old one) with the calmini springs but no body lift. The 'eyebrow' height is 55cm. This is with nothing in the car and no back seat.

thankyou britvit, i will compare it with mine 2morro and obviously add 50mm to the measurement.