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Re: Triumphs and Suspension Design

To: MGVR@yahoogroups.com
Subject: Re: Triumphs and Suspension Design
From: WSpohn4@aol.com
Date: Fri, 30 Nov 2001 10:23:09 EST
In a message dated 11/30/01 6:53:52 AM Pacific Standard Time, ggnagy@uu.net 
writes:


> > Nope - the track is narrow, and the morons that designed the suspension saw
> > fit to run the frame under the rear axle (as did the Austin Healey 
> geniuses,
> > on all but the last 3000's), so that when the axle bottoms on the frame, 
> it
> > lifts, and you lose adhesion. Makes for a car that is not NEARLY as
> > 'chuckable' as an MGA, for instance.
> 
> I thought some of the 'geniuses' behind underslung chassis were in
> Abington, with either the 'M' or the 'K' series?
> 
> 

The underslung chassis was pretty common, actually - welding up a flat frame 
was much cheaper than engineering the 'arch' required to span the axle, with 
enough strength that it wouldn't start to fold up in use.

Not too much wrong with the concept, either, as long as you had stiff shocks 
and sufficient suspension travel so that the axle rarely bottomed on the 
frame. Unfortunately, in racing, we put cornering loads on cars that they 
hadn't really designed for, which means that we have to try to deal with it 
after the fact, with stiffer shocks, heavier anti-sway bars, rubber snubbers 
reduced in size to give that extra fraction of an inch of travel before 
bottoming, etc.

Actually, Triumph was not the brightest light in the engineering firmament at 
the time. I had the chance to closely compare what the Triumph factory did 
with suspension, right from the beginning in 1953, with what an independent 
firm, using the exact same basic parts did - Swallow.

Early TR-2s suffered from a number of shortcomings - the front A arm mounts 
used to tear off the frame, the rear shock plates would separate from the 
frame, and you'd get fierce rear spring wind-up.

Swallow, who came out with the Doretti contemporaneously with the TR-2 (the 
suspension bits were, like the engines, derived from other models such as the 
Vanguard and Mayflower) did a much better job. They reinforced the front 
suspension mounts on the frame, something TR never got around to even in 
1962. They had a cross-over brace between the shock mounts at the rear to 
distribute loads and prevent them from ripping off the frame. They added a 
pair of locating arms to prevent axle wind-up. And they did all this when the 
Triumph factory was either too obtuse or too cheap to do the same thing.

But then the cars were never designed with the future in mind, just with 
making a profit that year and not eating it all up with warranty claims (ie 
the things had to last at least 12 months, after which they became not a 
liability, but a retirement plan for British mechanics).

I think that Colin Chapman was asked about the restoration of one of the 
early models of Lotus - a Formula Junior, perhaps. When told that the welds 
on the frame were insufficiently strong, he replied to the effect that they 
hadn't intended the cars to last 2 years, much less 20. Gives you mental 
pictures of a welder at Lotus running low on brazing rod when finishing a 
frame, and Chapman telling him "No, that's all you get, make it last - 
lighter is better anyway"

Bill

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