Suspension problems.

[martylemoo]

As you may have seen from the parts forsale section i have removed the 100% uprated torsion bars from my car. I refitted the original bars but now the car bounces like it is on a trampoline. It has the original dampers plus a 1000 mile old set of spax adjustables. It drove very well before with these bars although a little soft but i cannot understand the bouncing problem. Could driving on the island roads with uprated bars ruin the dampers that quickly? if so is there a test i can do with the spax once removed from the car?
cheers
Martyn

[Cam]

If it's bouncing then the dampers are not adjusted up enough!

[martylemoo]

Forgot to mention that, the adjusters on the front dampers just turns clockwise for ever more. It stops anti clockwise no problem. On the rear spax you get about 14 clicks from left to right. Could this mean my dampers are dead?

[KirstMin]

Hello, out of interest, why did you remove the uprated torsion bars? Several people have told me not to bother with them so what's the advantage of having them?

[Cam]

The advantage is a harder, firmer ride. It's personal choice really. Thicker torsion bars give a much more firm ride and more stability on the road as there is less up and down wheel movement (so the car body follows the road surface better - for want of a better description) but if you go TOO hard then the car will start to 'skip' on the road as there is not enough 'give' in the suspension to take the road surface variation into account so you loose grip. I have 100% torsion bars on mine and it's pretty hard (bit like a Mini). If I could choose again I would probably go for 75% but the 100%s are not bad!

Hmmm... If I remember correctly as you turn the dampers to a 'harder' setting you can feel the resistance on the adjuster getting more and more the further you go. I think I had about 14 clicks complete adjustment soft to hard.

Have you tried the old method of checking the dampers by bouncing the car? If it keeps bouncing then the dampers are not working properly, if it comes to rest after you let go then the dampers are working.

[bigginger]

Is it 'the old method'? I can't think of a better or 'newer' one.

[martylemoo]

yes the car just bounces for ever more, so i guess the dampers are shot to pieces. What baffles me though is before i uprated the car the original dampers were fine now after a few months of uprated torsion bars and spax dampers all of my dampers have died. What could have caused this? have you ever heard of this kind of thing happening before?

[Packedup]

Only thing that springs (sorry!) to mind is stiffer bars might speed up/ harshen the rebound, so the damper is being "sucked" back to the normal length quicker than it normally would be. Whether this would accelerate wear on the internals, or if it even happnes I don't know, just a stab in the dark really.

[Cam]

Is it 'the old method'? I can't think of a better or 'newer' one.

Perhaps I should have said the 'tried and tested method' As opposed to trying to figure out if they are working on the bench!

yes the car just bounces for ever more, so i guess the dampers are shot to pieces. What baffles me though is before i uprated the car the original dampers were fine now after a few months of uprated torsion bars and spax dampers all of my dampers have died. What could have caused this? have you ever heard of this kind of thing happening before?

Yep, sounds like the dampers are not working then! Usually the telescopics ONLY do the damping as it's common practice to remove the valve from the original dampers so that they just act as a top suspension arm. A few people leave the valve in and have 2 dampers and seem to have no problem either (just a little more damping).

It's unusual for telescopics to last only a few months. If this is the case then I'd have a word with whoever you bought them from! As for BOTH sets giving up at the same time, it seems that perhaps the originals were not in good order to begin with or something else has happened to the car that you are not aware of (parts being swapped etc).

Only thing that springs (sorry!) to mind is stiffer bars might speed up/ harshen the rebound, so the damper is being "sucked" back to the normal length quicker than it normally would be. Whether this would accelerate wear on the internals, or if it even happnes I don't know, just a stab in the dark really.

Well... the dampers won't travel as far so their operation will be limited which I would guess would negate any effect of the dampers wearing due to the speed of rebound but like you it's just a guess...

I have had SPAX dampers and 100% uprated torsion bars on my 4 door for about 4 years now and they are perfectly fine. So there must be more going on than meets the eye here.

[bigginger]

Wasn't taking the proverbial, by the way - I was expecting someone to tell me a better way

[Cam]

Don't think there is one unless you have an expensive test rig or a 'star-trek' tricorder (sp?) 'cause they can tell you everything!!!

[Onne]

My supplier told me, some of the KONIs he had fitted, had snapped, apparently because the don't like working under an angle!

[plastic_orange]

Spax don't like working at an angle - I went through 2 pairs very quickly on my Rover P6b - they were replaced under warranty, and eventually with Koni's which were fine. The spax on the rear of my Minor only lasted a couple of years till they expired - again working at an angle.
Mind you the Koni kit i put on my son's corsa - rear shocks seized after 1 day - replaced under warranty.
In other words i think it is just your luck how components last, but keep the receipts in order to claim on the warranty if required.

Pete

[bmcecosse]

Take the extra dampers off - and test them by hand ! Then check the oil levels in the normal dampers - and are the valves in there ? Or did you remove them ? I run standard dampers filled with 20W50 , AND large teledampers (non adjustable - what's the point !) at the front (standard bars). Beautiful smooth ride and great cornering. Even if the standard dampers seem to have oil - change it - because the long-chain molecules get ripped apart over time and the oil become useless.

[Cam]

AND large teledampers (non adjustable - what's the point !)

So you can set the damping level to what is required as the dampers are quite generic.

[bmcecosse]

What is required is as much as possible ! Colin Chapman was great believer in soft springing and maximum damping - for a good reason. My teles are big fat ones - no idea what car they are for - bought at autojumble. They WORK !

[bigginger]

Good Lord! Was he?
a

[Cam]

No it isn't. On the back of a Minor if you have too much damping it bounces around all over the place. After I fitted adjustable dampers to my 4 door I needed to fronts hardening (due to the weight) and the rear lightening (die to the lack of weight). I could not do this if I fitted non-adjustable ones!

Also, having the original dampers IN ADDITION to the telescopics will just increase the damping. If you fit stronger telescopics then you don't have to worry about the originals failing if you just use them as a suspension link (by taking the valves out). Makes for a more reliable damping system as the modern telescopics are less prone to failure than the lever arm types.

Colin Chapman was great believer in soft springing and maximum damping

Yes, as well as 4 wheel drive F1 cars and that nasty DeLorean business...

[bigginger]

Four wheel drive F1 Mog.

[jonathon]

I'd have thought Colin Chapman would have researched his required damper rates very carefully before having them made and fitted. I think BM is very fortunate that his big dampers suit his driving style, and cars weight, under all circumstances. I'd rather follow Colin Chapmans route of research and development rather than blind faith. If you have a purpose designed damper system fitted to your Minor, why then destroy this hard work by keeping the damping function of the lever arms, its about as daft as fitting coil overs in addition to torsion bars. Maybe I'm missing something here and could save a lot of time and money by trawling my local scrap yard and choosing the first dampers I come across!
Most dampers do not like being canted over at an angle as it induces premature wear. There are purpose designed suspension systems on the market for the Minor, the better ones work well and are researched the not so good are based on the scrap yardbodge theory of suspension.