Anti-roll bars - an admission of failure?

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
Spaces
Posts: 186
Joined: 16 Mar 2011, 10:42
Location: Rarely in one place for too long - Hebridean Islands and Yorkshire are my favourites
My Cars:

Post by Spaces »

Graeme, not sure if you're being Devil's Advocate for the benefit of this forum or if you genuinely believe a fwd car with strut front suspension, a stiff arb and rubber steering for the rear axle is genuinely better than the set-up a CX has?

If you don't adore the CX's dynamics, what do you appreciate about it? Perhaps the styling and early interiors? But surely what makes a real Citroen is the way it goes?

Regarding your questioning of the arb strength, that's a forum-filling bit of mathematics to prove things on paper - but I feel a massive difference between a Xantia and a CX on a road which isn't perfectly smooth. In a Xantia the obvious giveaway is the pronounced rock-roll which the neck has to deal with. In a CX, it just isn't there in the same pronounced way - in fact I've never noticed it in any CX or GS - or D, for that matter. The available roadholding and stability is subsequently of a higher and purer quality when the road springs and dampers don't have to deal with an unruly, undamped spring which both molests and unionises the otherwise independent front corners. Have a good look at the respective dimensions and engineering and you'll probably see what I mean.

Saab?
-for rallying? or road use? Who knows what's desirable without stating the aim. Is the aim success on a rally stage? Then Saab shows they are not desirable.
When it made its own cars (and was financially successful) arbs were absent from the large majority of its sales. One of the few manufacturers who really understood grip and roadholding.

As for 'vibration absorption' not quite sure just what you mean, other than the obvious that at 20mph a car with metal roller bearings connecting the double-wishbone suspension with the driver - instead of rubber blocks everyewhere - is bound to transmit the road more accurately. But unmodded new spheres (see my other post), cheap tyres and minimum 27 year old body-to-chassis rubbers (and everything else!) is not going to make a CX feel good next to a Xantia designed to appeal to the roundabout-infested Mum-taxi...
PeterN: "Honest John's forum put the last nail in the coffin of owning a 2000- car. Many were still servicable, but CR, DMFs and needing fault codes read because your horn doesn't work - no thanks. All my life I have generally understood cars - until now."
aerodynamica
Donor 2023
Posts: 1299
Joined: 26 Dec 2007, 18:10
Location: Glasgow
Lexia Available: Yes
My Cars: 2008 C5 Exclusive Tourer
1993 Xantia 1.9 TD VSX Mk1 Sinker A.K.A Slugmobile 13'
'Old Katy'
previous convictions: totaling 52litres of LHM in one go:
1968 ID19B 'Old Polly' Stellar white
1993 Xantia 1.9 TD SX Mk1 Sinker Silver
1992 XM 2.0 SEi Turbo Manual Anthracite Grey
1982 CX 20 Pallas 'Old Goldy'
1993 XM 2.1 SD Auto Light blue
1993 Xantia 1.9 TD SX Mk1 Sinker light Blue
1982 BX 16 TRS 'Cyril' Vallelunga Red
1995 Xantia 1.9 D SX Auto Dark green
1977 CX 2400 Pallas C-Matic 'Aphrodite' Regatta Blue
1982 GSA Pallas SE Silver Pearl
1980 CX 2000 Reflex Vallelunga Red
1978 CX 2400 Pallas C-Matic 'Prometheus' Midnight blue
1984 BX 14E 'Cecil the slugmobile' Maroon
1987 Fiat Panda 'the mighty panda'
x 97

Post by aerodynamica »

Definitely Devil's advocate! just can't resist a bit of Critical analysis when someone puts such effort into their arguments and generates strong points. Harks back to my days as a Philosophy student...
is bound to transmit the road more accurately.
Haha! nicely put, but it feels at odds to the otherwise legendary absorbtion on the CX - true; it's a real trade-off between sensational comfort and losing all notion of what the wheels are doing and how close to breaking away the tyre grip reaches.
If you don't adore the CX's dynamics, what do you appreciate about it?

Me personally? Well, I'd need to take take issue with the rhetoric there; it's not a dichotomy: that I see the CX is being not 100% perfect doesn't equal 'not adoring; its themes. What do I appreciate about it? It's quite a list! In fact anyone in the Citroen car club might recall my writing at length on the CX's virtues both dynamic and design (and a little bit of the design that's dynamic :wink: ) So, it's the overall theme of the car, warts an all. I happen to think the CX's front suspension is brilliant - I was most interested in the use (GS too) of anti-dive geometry on the front and why they chose to use that set up. The BX, with its MacP struts, also had anti-dive geometry.

Ultimately, I love the DIRAVI steering and the steering wheel/dashboard ergonomics that appear to complement the steering function so well.

One thing that bugs me about the CX is the lack of hatchback.

I'm not sure I agree that the Xantia is so ordinary: I see strong Citroen heritage in its form. The rear wheel position recalls all the greats in that it's so much further back in relation to the overall length. I see it as a satisfying Citro-mobile (admittedly, my Xantia is an early Mk1 'sinker' and so appears to be very Citroenesque)

Darn, have to go!
Graeme M
2008 C5 Exclusive Tourer 2.0 HDi
User avatar
Spaces
Posts: 186
Joined: 16 Mar 2011, 10:42
Location: Rarely in one place for too long - Hebridean Islands and Yorkshire are my favourites
My Cars:

Post by Spaces »

Sigh of relief! :D

No, the Xantia isn't so ordinary - I have enjoyed many a long fast journey in them where many cars would have left me more tired, although beyond 400 miles it was always steering which felt cheap and tiresome. Good cars indeed, and arguably much more relevant to most of today's roads and conditions than most CX models are. I chose different spheres (and modified their damping) on a hydractive to reduce the harshness at legal speeds and I really enjoyed the car, the 2.1 engine was well-matched and at times it felt quite brilliant. Well-galvanised steel is a wonderful thing for the owner of an old car!

Suspension has come a long way in the last 20 years for many cars (thinking Escort to Focus) - but Citroen has been encouraged/forced to lose its technical superiorities which once upon a time made most cars feel like a wooden-wheeled cart in juxtaposition. It's fascinating to watch all the top brands playing with suspension in an attempt to combine comfort with sharp handling - as well as off-road abilities without the on-road heave and heel. Especially so when the emerging tech is Citroen-inspired from down-under and doesn't require computers and active control to enable it to work.

Comfort is the by-product of wheel control and this will always be the major let-down in an expensive car with conventional springing. Hence the Mercs, BMWs, Audis and Lexus(i?) all using alternatives. Once you've driven something with the engineering subtleties and fineries a car like the CX has in spades it is rarely forgetten - which is why I give the Pug based cars a relatively hard time, knowing what the company achieved without electronics and the added complexities of hydractive.

Since Citroen has a large following of keen youngish drivers, thanks to its insurance offeres, rally successes and the nimble, simple chassis of its smaller models then I would think they would jump at the chance to own a C4-sized car with rally technology embedded in its core. With a simpler version of the Heyring Kinetic suspension (was the rally C4's suspension all spheres and hydraulics or did it use steel also?) and Diravi steering I think they would have a runaway sales success on their hands. Ten years further down the line and thenre would be another generation who couldn't imagine driving a car with four coil springs shoehorned between wheel and body, trying to do several jobs at once and failing at doing any one of them really well.

I find it shocking that the problems the Audi and BMW engineers are trying to solve were sorted and productionised by Citroen in the 1950s, yet Citroen just isn't interested in engineering anymore (style is only ever skin-deep). Even more so that an Aussie art lecturer played around with Citroen hydraulics and fitted his modified system to a Toyota 4x4 over 20 years ago which could climb over a tree trunk, then sold his take on the French technology for millions - and which was banned from motorsport for its huge advantages and is now under Toyotas, Lexus and the new McLaren.
Last edited by Spaces on 11 Oct 2011, 00:18, edited 1 time in total.
PeterN: "Honest John's forum put the last nail in the coffin of owning a 2000- car. Many were still servicable, but CR, DMFs and needing fault codes read because your horn doesn't work - no thanks. All my life I have generally understood cars - until now."
Norlander
Posts: 75
Joined: 09 Sep 2011, 17:11
Location:
My Cars:

Post by Norlander »

... have enjoyed many a long fast journey in them where many cars would have left me more tired ....
Also superbly comfortable for when stuck in a long traffic jam (more a standstill, really) as we found out some years ago when a tanker load had spilled near Carlisle.
Chlorate
Posts: 612
Joined: 25 Sep 2009, 00:55
Location: Wiltshire
My Cars:

Post by Chlorate »

It's one of those "it depends" situations that exist everywhere in engineering.

But I wouldn't say that using an anti-roll bar was an admission of failure just because there are better systems are available.
It's vaguely like saying a spanner is junk because impact guns exist.

Alex
Citroen Xantia Exclusive HDi

previously:
Citroen ZX Volcane - RIP
Peugeot 106 XN... stolen and destroyed by Kent Police :evil:
User avatar
Spaces
Posts: 186
Joined: 16 Mar 2011, 10:42
Location: Rarely in one place for too long - Hebridean Islands and Yorkshire are my favourites
My Cars:

Re: Anti-roll bars - an admission of failure?

Post by Spaces »

Not quite your spanner/impact gun argument chlorate since a spanner frequently works better than an impact gun. Whereas the less the need for an arb/the weaker it is, the more comfortable and stable your car will be - unless you never venture much beyond 50mph off the motorway and your roads are smooth ones, infested with roundabouts. The antiroll bar can appear to be the miracle of suspension (especially since it costs only pennies to the manufacturers) with its ability to prevent a cheaply designed and made car from heeling too much (without over-stiff springs and dampers) but as I pointed out above, you rarely get something for nothing. Bear in mind it's more usual that the gains are smaller than the losses. Which is presumably why well-engineered cars attempt to minimise their effects or dispense with them altogether.
PeterN: "Honest John's forum put the last nail in the coffin of owning a 2000- car. Many were still servicable, but CR, DMFs and needing fault codes read because your horn doesn't work - no thanks. All my life I have generally understood cars - until now."
Post Reply