When this thread was active back in February I held back hoping that I would be able to find an old article by Paul Frere, which I had referred to earlier. This was a technical appraisal by a knowledgeable writer and had I found it, it would I think have substantiated the claim for the Aprilia rear suspension being the work of genius. Ironically about the same time there were reports of Paul’s death at the age of 91 – see this link to an obituary:
http://www.guardian.co.uk/sport/2008/apr/02/motorsports.france Paul was one of the Lancia D50 drivers and a Le Mans winner - I am pleased to see Jack Romano is to publish an article about Frere in the November issue of
Viva Lancia!Anyway, the article never turned up, but all is not lost because I have found another appraisal by one Ted Eves, which was published in the
Autocar in April 1984. This is a bit too long to post here on the Forum and I will send it to Jack with the thought that it should be published in
Viva Lancia! I am indebted to Grant Gibson for guiding me to this article and for his most interesting thoughts on the subject, which were prompted by me telling him that there were folks on the Forum who were getting critical about what they saw as the ‘delicate’ nature of the Aprilia irs. Grant’s comments are a delight and I will try to get his agreement to publish them.
Meanwhile, let me add a few more comments of my own:
First, I simply cannot accept the idea that Lancia was trying for full springing by torsion bars and had to put in the transverse spring because of shortcomings in that approach. It is inconceivable that such short bars could have coped with such loads - they would have been so rigid as to be too inflexible. Other fully torsion bar systems, such as VW, Renault and possible Citroen use much longer bars, which are frequently longitudinal (fore and aft), or in the case of the Renault 14 run the full width of the car. Had Lancia been intent on fully torsional suspension, they would have used coil springs, not short bars. Remember, the springing action of coil springs is torsional in nature across the cross section of the spring wire, i.e. they act just like very long torsion bars, unlike leaf springs, which have a conventional bending action.
Then, the idea that some torsion bars had to be welded in place does not invalidate the approach. By the 1960s these cars were well beyond their design life and will, at least in the UK, most likely have been submitted to some bodge maintenance. To find some of them that have been welded up after 60 years should be no surprise.
Finally, the issue of what constitutes a ‘neutral position’ for the torsion bars also needs thinking about. Clearly the neutral position will vary with the static load that is applied to the rear end of the car – it can’t be neutral in all circumstances. The Aprilia was designed to take up to three people in the back and it should be no surprise that the rear of the car needs to be loaded when re-fitting the transverse spring – that is after the torsion bars have been fitted to their correct datum marks. And remember the very clever vernier adjustment that made it possible to do this with some precision.
When I first faced this loading problem I contemplated asking the then mother-in-law and wife to climb into the back, but I recall stacking paving slabs in the open boot to be a better alternative. Thinking about it now I remember the bigger problem was that I didn’t have a trolley-jack then (nobody did!) and the job required some deft work with a selection of screw jacks.
More anon, but probably in
Viva Lancia! where the subject should get a wider readership, which it deserves.
If anyone wants to see the Ted Eves article, let me know and I’ll email you a scan.
Colin
And here below is a John Maltby photo from 1964 of Aprilias in the snow. This is here because it’s lovely and also because it enables me to track just how few (or how many!) members read these posts and bother to open images!
