About Those Helper Springs

[MonsieurX]

Hi,

If you have the littel red springs on your suspensions, you might have noticed that turning in a curve and loading the suspension is not exactly confidence building...

I haven't removed mine but we came across the discussion in Spa because in the double-left turn in Spa, you dont really get a steady suspension load. Lots of turns dont... And this could be the fault of the helper spring.

The spring helps a lot with high-frequency travel such as small bumps but when in comes to high loads, you're never sure if it is the helper or the big spring that's working... Any change in loads will also be felt as a jerking momvement of the suspension.

If I remove them, what can i expect? Very hard road conditions? Is it a big compromise in the rain? Harder to judge loads when cornering? Any infos welcome. I use my atom mostly on the track, but i drive it to the track also. I dont mind the hard bumping, but im aprehensive that the ride becomes too hard and unpredictable...

[Monza]

i don't think you are right in your analisys or example Xavier  :
in a long turn as the double left at Spa, your Atom has ALWAYS (means all turn long), load on your right suspension and much much more than needed to keep the assister springs fully compressed (the only case where the load will reduce is if you are making a full spin ).
So your car is not using the assister springs at this moment (on the right side) but only the main ones. Your bad feeling is not coming from them on this part of the track.

Do you have the normal spings or the Race springs ?

[MonsieurX]

Hi Pascal,

Thanks for your analysis!

How can i tell the difference between the two springs?

[Monza]

with reading the numbers written on the main springs Front/Rear and telling me , i'll tell you what you have : normal or Track/Race ones

[MonsieurX]

Fronts: 46/05 ERS 180-60-70
Rears: 35/06 180-60-50 (no ERS...)

[Monza]

you sure ??
i have an Atom here with Track option and it is :
Assisters Front : 20    Main Front : 60
Assisters Rear : 30    Main Rear : 70
Sometimes it was a little bit different but not with harder one front ...
So you have a problem if no mystake in your post.

[John Scherrer]

There are numbers on the Main springs and Tender springs.

The first numbers XX/YY are just dated batch numbers WEEK/YEAR

On my Atom 3

Front Main 180-60-50
Front Tender ERS 40-60-20

Rear Main 180-60-60
Rear Tender ERS 40-60-30

ERS = Eibach Race Spring          (product range)
180 = Length of spring in mm
60  = Internal spring diameter in mm

last pair of numbers = spring rate in Newton millimeters
Convert to lbs/inch by multiplying by ~ 5.7

So 60 N mm is about 343 lbs/inch

[Monza]

yes John, but never on Bilstein with Harder front than rear. 

[MonsieurX]

So what kind of rate should I have between the fronts and backs?
Why are the rears not the ERS kind?

I didn't post the number on the helper springs, only the main springs... will the helper springs' numbers help?

[Monza]

you should have harder in rear than in front !
For track, something like 60 front 70 Rear.
Why it's not written ERS ?? perhaps it disappears or perhaps not ERS but you know the history of your car better than us i think?
The main question in your case is : why it's not harder in rear than in front ??
don't you make any mystake when you put out your dampers to send them to revalving or when you put it back on your car ??

[John Scherrer]

Been doing some reading ..

I think our small springs are Tender springs.

Tender springs provide a softer initial spring rate, then deliver the final main spring rate when the Tender spring is fully compressed. The main spring is a linear rate, the Tender spring can be a choice of linear or progressive.
(It is the Tender spring coils compressing and hitting each other that causes the dreaded Aton clanking noises.)

Helper springs are designed and used to prevent the main spring becoming loose in the spring seat when the suspension is unloaded or at full droop. They have a very low spring rate and have no effect on the suspension characteristics.

[John Scherrer]

From the Eibach catalogue

Main Springs

[John Scherrer]

Tender Springs

[MonsieurX]

[quote="Monza"]
you should have harder in rear than in front !
For track, something like 60 front 70 Rear.
Why it's not written ERS ?? perhaps it disappears or perhaps not ERS but you know the history of your car better than us i think?
The main question in your case is : why it's not harder in rear than in front ??
don't you make any mystake when you put out your dampers to send them to revalving or when you put it back on your car ??
[/quote]

Hi Monza,

When i bought the car - used, i did not get any history from the factory - despite asking for it. The basic specs and that's it.

I marked the dampers (but not the springs) before removing them so im sure they are not in the wrong place. It could be that the guys who refurbished them changed the springs - but doubtful... I dont feel that the car's behavior has changed. It still unsettles (wants to go slide or dips in the rear) in heavy cornering with a passenger...

The ERS is not erased, it is just not there. Could someone confirm they have the same kind or setup of springs?

I guess i have to take it apart again, change the springs, and another geometry then...

[John Scherrer]

I only see 'ERS' on the red Tender springs ..