Ducato composite leaf springs

[Steve928]

We're currently on our annual search for a new van, a search that like in all previous years will probably end in failure as we can't find a layout we like as much as our current one. While my wife concentrates on the interior I tend to get down low and dirty and look at all the systems, tankage and suspension etc..

 

One van we quite liked was fitted with what I presume are composite leaf springs, as in the picture (the sage green bar in the foreground is the nearest spring) and I see that these have been available since the X290 in mid-2014:

"A new, composite leaf-spring is combined with an anti-roll bar to reduce rear suspension weight by some 15kg while maintaining high levels of body control, making it an ideal solution for motorhome conversions."

 

I'd not heard of these before and I wonder if anyone has any experiences to relate in terms of their performance, ability to carry weight etc. I noticed that the bump stops were well clear of the spring so perhaps the spring rate is softer and the ride more comfortable for example? As we'll be moving away from an Al-Ko chassis this time it would good to hear if selecting a van with these springs would offer any advantage other than the weight saving. TIA.

[Derek Uzzell]

Although I was aware that the Ducato X290 ‘camping-car’ chassis could have composite rear leaf springs

 

https://www.fiatcamper.com/en/product/perfect-layout

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Air-suspension-/48144/

 

I’ve never known which (if any) motorhome converter chose to use Ducato chassis having that spring type.

 

I don’t know what a Ducato composite spring looks like, but as the steel equivalents (like my Rapido’s) are black and the springs in your photo are not, it’s not unreasonable to think that your photo shows the composite variety. This USA link

 

https://liteflex.com/products/automotive-light-truck-springs/

 

refers to Ducato composite springs (with a photo) so it may be practicable to discriminate easily between the steel and composite variety by their design, not just on a colour-based assumption. My Rapido’s steel springs certainly don’t have the ‘bolt fitting’ on their front end that is visible on the far left of the spring in the front of your photo.

 

(Edit: In fact, when I studied more closely the relevant photo on the Liteflex webpage, a) the photo (attached below) has a file-name of “Fiat-spring.jpg” and b) it looks VERY like the photo you provided with regard to the cross-section of the spring and the bolts that fasten the ‘eyes’ to it.)

 

A magnet would prove this one way or the other, but the brochure for the motorhome itself might say if composite springs are fitted. (My Rapido has much the same clearance between its bump-stops and rear axle, so that’s not a reliable indicator.)

 

My understanding is that, besides a rear-suspension weight reduction of around 15kg, the composite springs will provide a useful increase in the rear axle maximum load datum for Ducato ‘heavy’ chassis. My 2015 Ducato Owner Handbook just mentions the springs in passing, with the caveat "Make sure that the leaf springs in composite material do not come into contact with any kind of acid.”

 

This advert for a 2020 Adria motorhome

 

https://www.geoffcox.co.uk/2020-adria-matrix-670-special-edition-exclusive/

 

says the following:

 

STANDARD NEW FIAT FEATURES

- FIAT Euro 6.d 2.3 140hp Multijet 103 kW

- AdBlue

- Start and Stop

- Higher power and torque output

- 60 L diesel tank & composite rear springs

 

So, given the extra weight of the AdBlue system that will be standard for 2020 model-year Ducatos, it may become the norm for the 2020 ‘camping-car’ chassis to have composite rear springs.