Front springs that last longer than OE Smart ones?

[tolsen]

Cheap Suplex springs for Roadster:
http://www.bmfautoparts.com/steering...005/Parts.aspx

[mac999]

I have PI lowering springs 40mm drop all round

[JimbobTheSailor]

JimbobTheSailor;n869572]Liberty ships broke due to poor welding practices. Early days of arc welding and the concept of pre-heating had not been thought of.

"Constance Tipper of Cambridge University demonstrated that the fractures were not initiated by welding, but instead by the grade of steel used, which suffered from embrittlement"

The cracks might well have propogated along the weld lines once they reached them, but they could start anywhere in the steel.

Pattern springs are normally worse than OEM since cheaper material quality more susceptible to brittle fracture is used.

Do you include Smart OEM springs in this statement? Given Smart's record on this, it seems like the pattern spring makers would have to actively try to find a material worse than Smart's to achieve this. Surely at least some of them just use the same material they use for all their other mid-level cars' springs, thus making their Smart ones better than Smart's?

Cheap Suplex springs for Roadster:
http://www.bmfautoparts.com/steering...005/Parts.aspx

Legend. Thanks Tolsen. Looking at their photo, I count 5.5 coils, whereas your Anschlers look like they have 6.5. And the overall diameter doesn't look that big. Would you say there's a lot of stress in this spring and that, given the price, the material is not likely to be good enough to handle this higher stress?

[tolsen]

I have worked on board Liberty ships so know more about them than most living beings today. Their steel plates did not have sufficient toughness, not even at room temperature and many Liberty ship suffered therefore brittle fracture often resulting in loss of life. The cracks were initiated from the heat affected zone adjacent to the welds in way of areas of stress concentration such as corners of hatch cover coamings etc.

Our springs do also suffer brittle fracture. I can't ever recall any spring snapping off during periods of warm weather. They always crack when weather is cold, wet and miserable, hence fitting the replacement spring becomes and equally miserable experience unless one has access to a heated garage.

My Smart is a 450 whose front springs are different to those on a Roadster. I suspect the Chinese that made the Anschler springs must have added more alloy elements to the spring steel thereby increasing the material's toughness at lower temperatures. If that was not the case, they should have snapped off by now.

Whether the Suplex springs will last is anybodies guess. The only way to find out is to try.

[Mr T]

I've had 3 sets on the front & 2 sets on the rear on my Mk5 & 3 sets on the front of my wifes Mk6!

What I found on the springs from Smart is a flaw in the coating where the spring is hung whilst coating. The last sets I fitted I painted this flaw first.

[madDan]

Erm My Roadster is on it's original springs 11 years and 156,000 miles on, I don't exactly avoid most potholes, I put it down to being on 15" wheels maybe?

[marcjero]

Hello are there any update on this topic ?
Who is the supplier for Smart ? Any experience with Sachs springs ?

Thanks

update : Monroe is offering coil springs with serious warranty (OESpectrum line 5 years limited warranty). Moreover they seem to leverage a progressive design (they call "side load compensation"). Part number are SP3675 and SP3676. Trying to get more details...

[tolsen]

Fatter tyres ought to reduce fatigue loading on these poorly designed springs.
On my 450 I have standard Roadster springs on rear and dead cheap China springs on front. Ride is particularly comfortable compared to how it was and I have not suffered any broken spring since these were fitted nearly four years ago. Before I had uncountable spring breaks and lost count. At least 12 broken springs since 2002.

[tolsen]

Just reread the whole thread. Looks like I fitted my dead cheap China springs in 2012 six years ago. Before I had a front spring snap on me nearly every year.

[marcjero]

I got answer from Monroe. Their coil springs have standard dimensions. Unfortunately they don't provide the progressive design for the roadster.
Was there any failure from the rear springs ?

[tolsen]

The rears are less prone to snapping off but happens. I have had at least two broken rear springs on my 2002 Smart 450.

I see Monroe offer the OESpectrum springs also for the 450. About £22 each front and £15 each rear spring.
5-year limited warranty but excluded is general wear out. Wonder what that means.

[marcjero]

https://www.monroe-oespectrum.com/do...gust_01-gb.pdf

Regular wear out could mean a lot of thing.. However a spring snap should not be considered as a regular wear out. So I suppose they are confident about the quality of their springs.

According to this thread http://smartmaniacs.co.uk/forum/the-...wering-springs
Eibach prokit doesn't lower the car. So I think these could be considered as a good quality OEM replacement then ?