19 replies to this topic

[lawrence]

Good afternoon people.

Im after a bit of advice suspension wise for my mini

 

Currently the suspension is as follows. She is also lowered but not excessively

 

Front

>New Red spot cones

>New gaz shocks

>1.5 neg deg lower camber arms (fixed type)

>Uprated tie rods

>hilos

 

Rear

>NS new cone, OS old cone

>Old gaz dampers both sides

>hilos

 

So my plans are as follows for the front

>change lower arms to adjustable and set to known well performing settings for camber toe etc.

That I think is going to be the best for her that end.

 

But the rear is my main issue.

Ive just bought some coilovers for the rear (gaz) that were a reasonable price considering they were fitted but never seen the road.

 

Is it advisable to fit coilovers to the rear or should I be thinking of a different plan?

If there is a different plan what do people recommend? I.e: Red spots on the rear and new shocks.

 

Thankyou in advance for replies

Lawrence

 

 

 

 

 

 

 

[nicklouse]

First see what angles you are getting on the front with the ride height set. You many not need adjustable sit might be sport on.

Coils on the rear are only any good if you are never going to change the driving load. They are a fixed rate and do not manage added weight in the rear without jacking the rear up when unloaded or fitting harder springs fir that time you might need them.

Rubber is perfect as it is a rising rate spring and easily manages the changes in load.

[lawrence]

Cheers nick, you always give a good answer,

 

Regarding the front I've got a homemade frame for my micra engine and I didn't make it on a jig. I know from a previous 4 wheel alignment that theres a difference and wanted to fit the adjustable arms to equal it out.

 

What are you referring to such as driving load? is that the amount of people and things being carried or is that the driving conditions i.e. variable road surfaces

[tiger99]

He means weight in the car, as has been discussed here many, many times. The coilovers can not handle that and are utterly unsuitable for Minis.

 

You can NOT correct errors in the subframe by adjusting the arms. You really need to remake the subframe, at least in part, and jig it properly.

[lawrence]

Its a good thing I'm asking then for recommendations regarding what to fit them. And I understand your viewpoint tiger99 however I am not talking about an error in the subframe any more than was already there from factory. In an ideal world a rejig would be better however that isn't going to happen regarding my car as much as I would love to.

[Cooperman]

For road use you simply cannot improve on the original type rubber cone suspension. It is true 'rising rate' springing at the right rate and is, quite honestly, a superb concept and design.

[lawrence]

Thankyou cooperman I do respect your words of wisdom.

 

Now do I get red spots on the rear too then or will it make the rear a bit too solid?

[AeroNotix]

Kind of related but from what I often read on here is that the mini's suspension design is superior and provides many benefits over the more modern day coilover design for the mini's use-case.

 

Why is that? What is so special and unique about the mini's requirements where it necessitated such a fundamentally different design? I know originally, at least, that packaging was a concern and thus the rubber springs were used.

 

Why have no other cars adopted a similar design?

[nicklouse]

 

 

Why have no other cars adopted a similar design?

cost.

 

and space. 

 

and comfort.

 

waste space with longer springs and you can have springs and shocks or struts

 

rubber is a natural rising rate spring and when mated to a suitable contact profile between the rubber and the cone you have an unmatched spring that works in a small space and offers limited wheel movement. start lowering the Mini and you have even less wheel movement and people think that a coil spring has half a chance of working better! 

[AeroNotix]

Personally I have no desire to lower a mini (and I think those that do are mad). It always interested me how the mini uniquely has rubber springs, though.

[Cooperman]

As 'nick...' says, the Mini has very limited suspension travel. Thus a spring was/is needed which starts of at a low poundage rate per inch of suspension travel, so that it is not harsh over bumps, but which has a increasing rate/inch of travel as the suspension travels upwards and the rate of increase itself increases until full travel is reached. It's a non-linear rising-rate spring.

Now this is difficult to achieve with a more normal length of coil spring, let alone a very short coil spring, but a suitable shaped piece of rubber of the right hysteresis is ideal. If you look at a Mini rubber cone spring, you will see the shape and can understand how this accurate rising rate is achieved. It is impossible to make a short-travel coil spring to match the rate and accuracy of the rubber spring.

As an 'older person', I can remember how the Mini was so revolutionary when introduced and how we marveled at its stability, road-holding and general handling in both lightly and heavily loaded form. It was so much better than more 'ordinary' cars and it is that superb suspension which has led to its true classic and iconic car status now. 

Why anyone would want to b****r-up that fantastic suspension with crap coil springs is quite beyond me. Of course, those wanting owners to waste their money will disagree, and for pure race applications where the tracks are totally smooth and the suspension travels little, it is a different matter entirely, but we are not talking race cars.

[timmy850]

So are you talking coilovers or coil springs? You mention GAZ coilovers in the first post but it seems everyone else is talking of rubber replacement coil springs?

 

Coilover e.g.

http://www.minispare...r-classic-mini/

 

Coil spring e.g.

http://www.minispare...r-classic-mini/

[Cooperman]

The bodyshell and damper mountings on the radius arms are not designed for taking the full suspension/springing loads as applied to those points by coil-overs, so they are unsuitable. They put the entire corner weight onto the damper mounting pin as a direct shear load, thus creating a huge additional load which will cause a fatigue failure eventually - well, that is unless the loads going into the damper top mounting have not already caused a fracture of the mount.

[Spider]

The design choice of Rubber for a spring firstly came about because the Hydrolastic System while in development, wasn't yet ready to fit in production. The Mini was first designed to use the Hydrolastic system. When it was clear that wouldn't be ready in time for first production, they did consider conventional springs very briefly, however, it became obvious very early on that to get the right balance of qualities needed, conventional spring types then in use (coils, torsional and others) simply wouldn't fit in the space available.

 

BMC Engineers worked that out in the late 50's. The Materials and alloys available today for springs is no different to back then, so how it can be thought a coil spring can do the job?

 

Coil springs are so much cheaper to produce than the rubber cones and as the coil springs are already in production, albeit, different sizes than what would be needed to supposedly fit a Mini, but the machinery is there, they clearly didn't choose a Rubber Spring (or the Hydrolastic System) for a cheap 'Peoples Car' over conventional springs for reasons of cost. It was chosen because it was what was needed to make the suspension system operate correctly with the space available.

 

For road going Minis, Rubber is unbeatable, even with all standard parts. If the next step is wanted, the Rubber set up is so much more tune-able than any spring could ever be.

 

Some of the Moke touring Guys fit Coil Overs to the rear end of their Mokes, it does not replace the Rubber set up, but supplements it for the loads we carry and to retain a respectable (and very necessary) ride height. When loaded up with 300 kg+ of gear in the back, these ride very nice, but when empty, they are very aweful - too harsh.

[lawrence]

Coilovers Is what I was talking about yes not cone replacements to the spring type. 

 

I do thank everyone for their input and am planning to sell these current coil overs and but some new rubber cones.

 

Now do I get standard ones or minispares red dot ones? to go with the gas shocks