.

Often 'sport springs' are a little shorter than the standard springs … which [other things being equal] stiffens the spring, and lowers the ride height. [*]

Sometimes, however, they are 'progressive rate'

MichaelG.

[with no experience of Astra Estates]

.

[*] which is also true of cracked springs !!

Edited By Michael Gilligan on 07/03/2019 23:57:24

Possibly aftermarket springs of inferior quality fitted by a previous owner to stiffen up the rear under load?

You don't say what model astra you have but if it was a "sporty" model then they would have been OEM springs but to a different spec than the bog standard model in which case garage was right to replace like with like.

They may also put stiffer springs onto the estates/vans as they expect them to carry more load and the standard softer ones may bottom out.

Edited By JasonB on 08/03/2019 08:48:42

A car's suspension is designed mainly to keep the wheels in contact with the road, but there are other factors. Most important is the state of the road:

• if you live in a country with bumpy roads (perhaps back roads) with plenty of room for corners, it's best to go for comfort. American cars of the 50's are optimised for these conditions – very softly sprung, high-riding, comfortable despite pot-holes, but not good at going round tight corners. Driven on good but bendy, busy European roads, this soft suspension becomes a positive disadvantage; the car rolls and sways around corners and pitches during braking and acceleration. Not pleasant to drive, and passengers get seasick.
• at the other extreme is the racetrack. A loop of straights and corners with a good surface. Cars travel at high speed and driver comfort is secondary to keeping the wheels firmly on the road. On a race-track, it pays to use much stiffer springs, with much less travel, and the car close to the ground. Roll and pitch are minimised. Because the suspension is optimised for performance throughout, it's weight and travel is reduced. Changes might be made to all the parts, not just the springs. Taken to the extreme, the driver has a hard ride, and the car cannot cope with pot-holes at all. It follows that driving a Formula 1 Car any distance on an ordinary road is absolute poo, and back roads out of the question.

Most cars are set up for crowded developed nation road conditions, with the suspension tuned slightly soft for safety and comfort on good roads. Not ideal for someone who does a lot of motorway driving, or enjoys rapid cornering.

Within the range of very soft and very hard a stiffer suspension improves road handling at the expense of comfort, and – as we know – many drivers like sporty, if only for bragging rights! Robin would have to read the Astra manual to confirm, but I suspect the suspension is factory fitted and is a bit different to that on the ordinary Astra. Standard springs might not fit, and if they do, they might adversely affect the car's road handling.

Dave

Had a stand up with the service manager at the local Fiat main agent when my Punto was tested after three years ( From new ) and they found a broken front spring. 11k miles. They were only going to replace ONE side. It was a paid job, not a warranty case. He said that the company refused to replace a pair if under warranty so they only kept one in stock.

About £50 a pair from the flee but that was the price each from the agent, plus of corse fitting plus VAT. and no, I gave up the boy racer bit about thirty years ago.

Regards Ian.

Edited By Circlip on 08/03/2019 11:25:07

According to Honest John (D T motoring supplement ) the problem is that most European car manufacturers leave the ends of the spring wire just as sheared, whereas Japanese manufacturers grind the ends so that, on a flat surface, the spring would sit vertical. This reduces the stresses in the springs.

A friend who is a great VW / Skoda enthusiast has had several springs break on his cars (different models ).

"If only everything was as reliable as a .."

The exception to this may be Renault. When we had Renault 5s, in 17 years, (110K miles each ) there were no spring problems, BUT the upper and lower spring seats were angled to match the spring, to minimise stresses.

In 12 years, of ownership, (80K miles each&nbsp neither of our Toyota Yaris, had any spring or damper problems. The only parts needed were a set of brake pads, a set of tyres and a brake light bulb, each.

Where I worked, before retirement, although volume production, we tried to design in quality and reliability.

But we still had a sound aftermarket. A moral there, perhaps?

Howard

.

Sport springs are usually higher rate than the standard ones, say 100 lb / inch instead of 80 lb / inch. to reduce roll, and effects of it on roadholding.

So, if you are carrying loads, the suspension will settle less.

Lowering the suspension, to lower the centre of gravity, by cutting one or more coils off the springs was bad news,

Although it increased the spring rate, it often increased the spring stresses beyond the maximum, leading to breakage.

Similarly, fitting spacers between the wheel and hub, increased the track, but moved the load line off the design point, increasing the load on the outer bearing; again risking premature failure. And on the front wheels, it upset the steering geometry because the point of contact with the road no longer coincided with the projected line of the steering pivots (what used to be the king pin )

Howard