14 replies to this topic

[paul1380]

Hello Guys was wondering if any one has changed their suspension rubber cones for springs?

I have changed them but seem to have a rattle on the front springs when going over a speed bump. I have jacked the front up to see if they were loose but no movement. so i double checked whilst it was on the floor and still no movement so completely stumped. It's not bothering me just wondering if any one had any ideas?

Thanks for any help. 

[tiger99]

Well, I am not surprised. The Mini is entirely unsuited to the use of steel springs, and is critically dependent on the use of very non-linear rubber cones in compressive shear to get satisfactory operation within the constraints of the small amount of suspension travel due to the short wishbones.

 

The ONLY way of getting a progressive rate (and even then it will not be progressive enough) from a steel spring is to design it so that the coils gradually close up and make contact, so the operational length of the coil becomes less as it is compressed. There can be some kind of soft buffer between coils, such as spring assisters used on conventional cars sometimes, but generally, especially within the confines of a Mini, the turns just touch. Not surprisingly they may be somewhat noisy as they do that. It also results in damage to the paint or other coating, which encourages local corrosion and the resulting pitting leads to fatigue cracking. Variable rate coil springs in the environment under a car are a really bad idea.

 

Also you are probably having excessive and fairly violent bump stop contact due to the inadequacy of the springs. That may be noisy.

 

You can't change any of that except by putting the suspension back as it was originally and properly designed. However there is one more thing, did you replace the knuckle joints? These are not very expensive compared to the damage to top arms and rear radius arms that will occur when they wear through.

[Dusky]

Give us some More info, what ride height, what springs,...

[Spider]

If your knuckle joints are stiff, the springs can 'tap' on the subframe.

[tmsmini]

I am not sure if Minispares sells this:

http://www.minimania...--Mini-Cooper-S

 

But they do help with excessive droop when using springs

[Cooperman]

Coil springs are really for racing where a high initial spring rate is needed to reduce turn-in body roll.

On a road mini, despite what some may say, they are entirely the wrong spring medium. There is no substitute for the superb rising rate rubber cone springs which were and still are the basic key to the super Mini suspension.

[limby2000]

Ive got the minitastic springs (fast road), the back ones have a plastic seating ring but the front is metal on metal, perhaps thats the problem, i have heard there can be an issue with a metallic noise but i,m yet to use mine in anger.

[Spider]

Coil springs are really

 

not for Minis.

[Alice Dooper]

I fitted the Minitastic fast road springs with new knuckles, HiLo's and GAZ dampers (the lowered ones) on a Sportpack with 13x7" rims and have had no hassles. The difference in the car is amazing, handling still the same but the comfort is massively increased.
Although my front donuts were pretty worn, I had decent Koni shocks in. There were a few sceptics here, but were converted when they had a run in the car. It certainly doesn't look like there's a lot of travel distance for springs to work and they look really short, but they seem to be just fine.

I was told that when fitting the springs to buy the lowered dampers as the front ones can unseat when unloaded. Apparently the cure is to drill a small hole in the Hilo and tie wrap them together. I dont think it sounds to me like the tie wrap would last long. I fitted the minitastic HiLo's with lowered dampers and they don't seem to have the problem.

I did have a new rattle, but it turned out to be the upper engine steady, don't know why we didn't hear it before.

[tiger99]

Using a tie wrap in that way is illegal and dangerous, and will invalidate your insurance. The suspension components MUST be chosen such that knuckle disengagement is impossible. That means springs with a longer free length and/or thicker rebound stops, or hammering the dampers to bits by using them as rebound stops.

The only way it is achievable with steel springs is to have a second soft spring, which goes solid except under full rebound conditions, on top of the main spring. That is regularly done with coil-overs, but on a Mini there is no way of positively locating the springs to each other.

Certain Metro models had a small auxiliary coil spring between knuckle and trumpet at the rear for much the same reason.

[Dusky]

I never had that problem with my minitastic springs. I'd look for a problem elsewhere. Unless your ride height is much Lower than the advised one , wich also contributes to some ( cheap) springs breaking prematurely( they dont come with proper instructions on ride height and Are probably not even tested).

[tiger99]

So who says the minitastic springs are properly tested? To what standard? Under what test conditions? For how many tens of thousands of miles?

 

I would suggest that unlike the rubber cones, their development and test program has been utterly inadequate, like a lot of aftermarket bodges.

[Artstu]

So who says the minitastic springs are properly tested? To what standard? Under what test conditions? For how many tens of thousands of miles?

 

I would suggest that unlike the rubber cones, their development and test program has been utterly inadequate, like a lot of aftermarket bodges.

 

Hmm wasn't the rubber spring a bodge because the hydrolastic system wasn't quite ready ? http://www.moultonbu...tic-suspension/

 

 It was originally intended to be featured on the Mini, but wasn't quite ready when the Mini was launched. The first Minis with Hydrolastic suspension were produced in 1964.

Edited by Artstu, 12 August 2016 - 08:27 PM.

[Dusky]

 
I would suggest that unlike the rubber cones, their development and test program has been utterly inadequate, like a lot of aftermarket bodges.

Stating this without KNOWING any of this might leave you with legal issues, atleast it would do so in Belgium.

Have a word with them,they're very helpfull.

[Carlos W]

 

 
I would suggest that unlike the rubber cones, their development and test program has been utterly inadequate, like a lot of aftermarket bodges.

Stating this without KNOWING any of this might leave you with legal issues, atleast it would do so in Belgium.

Have a word with them,they're very helpfull.

 

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