rear shocks for a Bronze

[M.Ouvinen]

I've got some GAZ coilovers in the rear, and I'm not that happy about the suspension. It seems very hard, and yet still it seems to bottom out in the worst bumps. Any ideas in how to make it more progressive? I guess using two separate springs would be a good start, one for the iniitial plushness and the "sag" (as it's called in mountainbiking) and the stiffer and longer spring for the bigger bumps. And maybe dial in more damping on the shocks?

The rear wheel alignment is also a bit wonky, but it's symmetrically wonky, so I guess the suspension mounting just is a bit wrong. It's got some negative camber when sitting still, and it looks almost like a swing axle. (And handles like one too, plenty of lift off oversteer.) I will have to take it to my Mini specialist some day anyway, so we'll have a look...

[Stuart]

I'll make a guess that your dampers are more or less at full extension at rest? that's what gives the harsh crashy ride over pot holes.

On the two mk2's I have the rear-beam was too far to the right hand side when viewed from the rear, mine seem to have positive camber.

Brian Bronzenut (who hasn't visited this forum) has his radius arms on upside down, the right one on the left, and the left one on the right, he says he now has some negative camber and the suspension seems to work much better like that.

I'll see if I can get him to join the forum and explain it a bit better than I have.

[Alan D.]

Hello all,

This a copy of a post which I placed elsewhere on the forum regarding making a new rear beam, but it may have some relavance on this thread!

Hi

This is a problem I need to address in the future, but I'm busy at the front end of the car at the moment.

I've not put a lot of thought into the subject as yet. Aluminium would be great as long as you have the facilities for welding it! I think Stuart has put a bit of thought into the problem and tried to source a standard aluminium channel, don't know how far he got with it! The problem that I've found with making things is that you have to buy say a seven metre length to get 1.2 metres! That's not so bad if you make a few extra and recover your costs, buy selling a few.

There are a number of Mini beams on the market and as far as I'm aware the only difference between the Mini & Midas is that the Midas has a narrower track! I wonder if you could buy a Mini beam and cut it down, possibly rejigging the mounting holes etc. One of the problems which I believe occurs on Mk1 & 2's is that the centerline of the front subframe is not the same as the rear subframe centerline, due the holes in the heel board being put in the wrong position during manufacturing of the shell, so the car has a slight crabbing action! If that's the case it's probably best not to use the existing mounting holes and start again setting up the rear beam around say a centralised laser line.

The other advantage about using a Mini beam, is that you can get them which are adjustable for camber and castor.

The other point to think about is the possibility of using Metro Radius arms which would increase the track!

Just brain storming, well you have to start somewhere!

Alan D.

Posts: 15
Joined: Fri Dec 05, 2008 9:34 pm
Private message

[M.Ouvinen]

I'll make a guess that your dampers are more or less at full extension at rest? that's what gives the harsh crashy ride over pot holes.

On the two mk2's I have the rear-beam was too far to the right hand side when viewed from the rear, mine seem to have positive camber.

Brian Bronzenut (who hasn't visited this forum) has his radius arms on upside down, the right one on the left, and the left one on the right, he says he now has some negative camber and the suspension seems to work much better like that.

I'll see if I can get him to join the forum and explain it a bit better than I have.

Ah, I did actually mean positive camber. That's what I've got. Like a swing axle at rest. Trying the switch the radius arms is something worth a try.

I guess that doesn't solve the harsh ride though. Any suggestions for springs? What kind of spring rates are we talking about? Or should I just ask my locla Mini specialist? They've got some coilovers with springs that look like progressive coil springs to my eye.

[Stuart]

I've made my suggestion about spring rates earlier in the thread. Avoid 1.9" ID springs and also the off-set Mini-type ones.

[M.Ouvinen]

Ahh. I missed that.

Will have to try that but don't know when. I have no garage to work in and no other means of trasnsport at the moment. Maybe it'll have to wait until summer comes. I plan on getting me something totally different for the summer. I'm thinking something American, fullsize, early 70's. Or then again, a Citroën ID/DS or a CX. No use in dreaming, something will come along.

[rocketron]

While reading this thread on coilovers and spring rates and also the article in the 01 midasforum magazine, some memories came to mind. In the late 60's I had a Mini with virtually new suspension throughout and new Koni shocks allround. Whatever engine I fitted, the biggest being 1365cc. (yes, I built one, with Triumph 1300 low compression pistons) this car handled and cornered far better than my Midas mk1 ever did. The only difference I could see was wheelbase and coil overs on the Midas rear. At this point, I was puzzled since all other components were practically new anmd the same in each case. The Midas was fitted with the original single rate spring and new Spax shocks (yeuch). I'm no expert on suspensions etc. but the Midas always seemed to "roll" more at the rear than the Mini. I then fitted new original Midas dualrate springs to the rear and a little improvement was seen.
A college friend had a built a Mini Marcos, super-tweaked 850 and no coilovers. This little beut handled and cornered even better than my mini.
Some years ago, a club member had a Road Rally Mk1 Mexico with single leaf slipper springs on the rear which also handled amazingly. It was rolled quite badly on an event, the roof was brought down to the waistline at one point, but it still handled as well as ever! Back at the workshop, the suspension was checked over fully, using a body jig, all the suspension points were in their original locations: the suspension still worked as pre accident. A new car was built, a MK4 Escort converted to front engine/rear drive and to take all the suspension, 5-linked, slipper spring, Atlas axle, from the rolled Mexico. This time, coilovers and panhard rod were fitted to the rear. In an attempt to reduce the rear end roll, various springs of different rates were tried, ending up with 600lb/in springs! As you can guess, effectively no suspension. If the inner rear wheel went over a small pebble, the whole back end would skip out.
At this point the car was crap compared to the Mexico. The shocks were adjusted allover the place but to no avail.
None of us were suspension experts, but we could safely say the problem was connected with the coilovers somehow.

With ref to all the above cars which we thought handled the best, they used original manufacturer's spring pickup points, Mini and Marcos were the same (at about axle centre) and the Mexico, although slipper spring, still used original points. So we thought, on a simple level, did moving a spring connection point to a higher point in relation to the road cause more rear end roll?
After loads of tea, choccy bickies, arguments etc and Alan Staniford's book on suspensions, we decided to not fit a rear anti-roll bar to the Mk4 Escort, but to move the panhard rod pick-up further "up" in relation to the axle centre-line. This made a substantial improvement, so much so that we ended up with 170lb/in rear springs: a long way from the 600lb/in.

Now, I realise I may be shot down in a mass of flames and snot, please forgive me but should we, perhaps, consider that coilovers, although successful in many cases, may be a problem with Midas? Why did Issigonis not use coilovers?

Best regards, Ron

[skip_rat]

My Mk2 seems to have the mini coilover Gaz dampers with the offset mounts. Both the damping rate and the spring platform height are adjustable. Currently the platform is set to about halfway up the threads and the dampers are at their softest setting. The springs are the progressive type (more coils at one end than the other) and I dont know the rating.

I haven't tested it any further yet as the engine isn't running correctly, the offset mounting makes me wonder how I would change the spring........