Xantia: Low back side

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

Moderator: RichardW

User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Post by Mandrake »

citroenxm wrote:Hi

A Xantia will NEVER ride as good as a CX or DS, and possibly an XM!

The heavyer the car, the better the ride, as the way it was designed!

The DS was a heavy car and the system was designed for that car.

I think the Computer Control on the XM spoils it slightly.. but its still worlds ahead of Springs and Dampers!!
I don't think weight is the answer, a Xantia and a CX are actually exactly the same weight! (1300Kg +/- a bit depending on the model spec)

And dont forget the GS - one of the best riding small cars of all times, is a paltry 980Kg, which is less than even the plastic BX :lol:

It's a number of factors IMHO:

* Amount of suspension travel - the CX just has more usable suspension travel than a Xantia, period. At the front its quite a lot more, a couple of inches extra, and it does really make a difference.

(You can fly over wide backed speed bumps with ease in a CX that bottom the suspension in the Xantia) The Xantia only has a similar amount of suspension travel to a GS - a much smaller and lighter car.

The softer the springing is the more suspension travel you need to prevent it bottoming - and a Hydractive 2 Xantia is actually sprung a bit too softly for the amount of travel it has, IMHO, so it tends to nudge the snubbers quite a bit on undulating roads, which spoils the ride and damping.

* McPherson struts vs double wishbones is a no brainer - McPherson struts will always be inferior, and this is probably the single biggest difference between a CX/GS and a Xantia.

Not only does a McPherson strut have a significantly compromised geometry (which matters a lot on a car with soft springing and plenty of travel) but under dynamic conditions of cornering, braking, accelerating etc the static friction of the strut increases, which compromises ride, damping, and tyre contact. McPherson struts are cheap and compact, nothing else.

* Lack of centre point steering - the Xantia's McPherson struts have high KPI typical of struts, (about 13 degrees) while the GS had zero KPI with perfect centre point steering which gave a brilliant zero-kickback manual steering system.

The CX has some kingpin inclination because of the brake disc interference, but gets around the problem with the design of the DIRAVI steering system.

* Unsprung weight - the GS had a real advantage in that the unsprung weight was massively less than typical due to the inboard front brakes. The sprung to unsprung weight ratio is a key factor in ride quality and handling and its especially important for light cars - the GS, being a light car, never would have ridden and handled as well if it had normal discs in the wheels. (The DS also had inboard brakes)

The Xantia has relatively high unsprung weight at the front, (ever tried lifting a new disc?!) but to be fair, so does the CX.

Stiffer rollbars were mentioned for the Xantia, but I don't actually think they are all that much stiffer than a CX - when I had mine up on ramps with weight on one wheel and the opposite wheel hanging in mid air I was trying to tighten the wheel nuts and the wheel was moving several inches just with me pulling on the tyre lever - which would have been twisting the rollbar...

I think the reduced body roll is more to do with the different roll centre of the McPherson struts, and the particular geometry they chose for the CX/GS. (Which has fairly equal length arms, and therefore quite a high roll centre)

Another thing in the favour of the CX for ride is that it has full rubber block isolation between the seperate suspension chassis and the body - something even the GS didn't have, so the CX is very "rumble" free.

Regards,
Simon
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
deian
Posts: 1729
Joined: 26 Feb 2006, 10:53
Location:
My Cars:

Post by deian »

I'd love a CX though, i was looking at the price guides in the classic car magazines, not too bad really. Top price for a CX GTI Turbo 2 is about £3250.

It really is a shame Citroen didn't carry on using the double wishbones on all the hydropneumatic cars, I reckon it's peugeots fault.
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

jeremy
deian
Posts: 1729
Joined: 26 Feb 2006, 10:53
Location:
My Cars:

Post by deian »

didn't manage to open that link,.. is it the grey gti 2 for £1900? thats been on sale for ages? very nice it is, i think £1900 is a little steep?
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

Yes that's the one - anything for sale is only worth what someone will pay for it so could be dear.
jeremy
steelcityuk
Posts: 1053
Joined: 03 Jul 2006, 21:51
Location: not applicable
My Cars: not applicable
x 1

Post by steelcityuk »

Somehow the CX has never really appealed to me, though if it did it would have to be a diesel. However the DS is another story (and another large amount of money).

I'm looking forward to getting my XM on the road. Strangely it feels more like my wifes 405 to manouver than my Xantia. Come to think of it, it's alot like a BX, which shared it's under pinnings with the 405.

Only once went in a GS, sadly the only thing I remember was the placement of the stereo.

Steve.
not applicable
Post Reply