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MG MGA - Rear Shocks Conversion?

Just had a pleasant half-hour searching the archive on the subject of converting the old lever-arm shocks on the rear of my A to telescopics. There isn't much info on there about the conversion, and nothing recent. I notice Moss does a selection of different kits using a variety of makes - Spax, Koni and Gaz - does anyone have experience of this conversion, and which shocks to use? It all looks quite simple to do. I don't want the ride to be any stiffer - more compliant if anything. My rear suspension setup is pretty much standard. Your views would be appreciated. Thanks, AB
A Bennett

AB
There is lots of advice on the MGB boards - the nub is to avoid - most are too stiff.
Roger Walker

AB
My car came with a rear telescopic shocks conversion when I got it.
They were adjusted to to the midway position at first but the ride was extremely hard.
I put up with it for a quite a while (a few years!)but then when James at Bob Wests advised me to re-adjust it to the softest position the ride improved dramatically and the car handled just fine that way.

So to be honest, I am in the process of converting back to lever arms which work really well on the MGA.

You can (or could at onetime) get uprated competition (stiffer) valves for the lever arms which may do what you want.

The standard rear springs on the MGA are already really stiff and dont really need to be any stiffer to be honest.(imho)

My car has lowered and much stiffer front springs with lowered rear springs too. The ride is really hard and although it is great fun on smooth road surfaces, it is so badly affected on poor road surfaces that I sometimes struggle to keep up with MGAs which have standard suspension.

So, although I do like the look of the lowered car, I will at some stage convert it back to nearer to standard settings.

Colyn


c firth

When we lived in Montana I commuted with a 1970 MGBGT. I had 10 miles of gravel each way and the car went up and down on washboard very unpleasantly with rebuilt lever shocks. I switched over to tube shocks and the ride improved 100 percent. It was a easy switch on a MGB. I think I turned the plate around and upside down so it would line up with the shock but that was 15 years ago and my memory has dimmed. With that said I never considered switching the MGA and just slowed down on the bad roads. Now we have all pavement but tube shocks are a change I would not ever consider on the MGA in any scenario.
Bill Haglan

I personally would not do the tube shock conversion. I have it on my MGB and I will convert back to the lever arm shocks. The geometry of the tube shock conversion is off, and the top mount is very strained and the damping movement is not in a proper line.

With the MGA I feel it would be easier and better (in my opinion) to have the dampers adjusted, by either changing the valving. (Peter Caldwell can help you with this) or use the next grade heavier oil in the damper.

I use #20 motorcycle fork oil.... #30 would stiffen the action.

There is my 2 cents.... CR
C.R. Tyrell

My car had been converted to telescopics by the previous owner and I find the rear to be really hard, verging on the distinctly uncomfortable. A lot of my driving is on minor uk back roads where pot holes/poor drain covers are common and catching one of those hammers the dental fillings. I run quite low rear tyre pressures to remove some of the jolt.
I don't know how this would compare with lever arms although my Frog with quarter eliptics and lever arms rides the bumps much better.
Graeme Williams

The problem with rear telescopic conversions, and the reason they have such a bad reputation, is almost entirely the result of poorly chosen shock absorbers, that are far too stiff for an MGA (or MGB) application.
About 15-20 years ago a Sydney mg specialist worked with a nation wide suspension firm (Peddars) to come up with a shock absorber to suit the MGB. The "test mule" was an MGB GT. They observed that an MGB is "very light in the back". (An MGA roadster is obviously far lighter still).
They found ALL gas shocks too stiff for the purpose, and ultimately designed and manufactured a conventional oil filled damper for the unique to the MG application. This shock absorber was quite "short and dumpy" in its appearance and looked very different to most others I've seen used in MG conversions. Around Sydney they sold hundreds of the kits. I fitted one to my mgb roadster and was quite delighted with the more supple ride and surprisingly at the same time, greater roll resistance.
The main benefit appears to me to be the elimination of linkages, and therefore "wasted movement" through the direct action of the shocks, and the reduced friction in action.

I'm not sure that "not working in a proper line" is an issue. Many applications have tubular shocks installed in an angled orientation. The for its time, the very highly regarded Velocette motorcycle had a pair of rear shock absorbers that were adjustable through an arc to stiffen and soften the rear suspension. The system was designed by the very highly respected Phil Irving, also the designer of the Vincent motorcycle and later the Repco Brabham F1 world championship winning engine. He was a hugely gifted engineer, who it seems had no problem with angulation of the line of action of a telescopic shock absorber.

Having said all that, a set of lever arm dampers (in good condition) work fine on an MGA. That's what I have on mine, and it suits the character of the car very well. My foray into the MGB conversion was mostly just out of interest, but I was surprised how readily palpable the improvement was. I've not heard of anyone who fitted this particular conversion reverting to lever arm dampers.
T Aczel

Just two bits on telescopic shockers from me:
1) Bob West doesn't recommend them.
2) My standard lever arm units work just fine.
Seems a no brainier to me!
Bruce.
Bruce Mayo

In my view the ability to buy new rear lever arm shocks been a game changer.

In the 1980's when this wasn't possible I had the choice of trying to find a usable set of 30 yo rear units or fitting a Spax rear telescopic conversion to my Bugeye Sprite.

I have no idea whether the rear shocks were too stiff for the car, but they were a quantum leap ahead of the "rebuilt" rubbish I had previously had on the car.

The bottom line in 2015 for the MGA is that you can fit new shocks that work and are the same spec as the originals. Why wouldn't you?
A Bowie

My dentist recommends Spax!
Graeme Williams

Graeme,
does your dentist recommend Spax for altruistic reasons or more as a means of increasing demand for his services?

Although he could always argue that the "spray" of tooth enamel chippings that settle onto the road surface from spax shod MGA drivers could increase tyre grip around the worst bumps and therefore be actually providing a public service. :-)

Colyn
c firth

> The bottom line in 2015 for the MGA is that you can
> fit new shocks that work and are the same spec as the
> originals. Why wouldn't you?

Because I sent my originals to Peter Caldwell to have them rebuilt better than new. Thus preserving just a little bit more of my dad's car. 3 of the 4, at any rate. I substituted one from the parts car for the RF unit with the oversize holes.

-Del
D Rawlins

Thanks chaps, my reason for posting this thread was obviously because I was planning a change to telescopics, to cure a clanking noise from the rear suspension when going over deeper potholes, as well as for looking for a modern, softer ride. Thanks to your experiences, I have now abandoned the idea since it would obviously result in a firmer, not softer, ride, which I do not want! Instead, I shall remove the lever arm dampers and links at my leisure over the winter, and inspect and test them thoroughly to see what is making the noise, and stay with the original setup. Thanks for saving me £200+!! Cheers, AB
A Bennett

Well, you may not be saving yourself £200! You don't know what you will find when you can wave the lever arm about not connected at the business end.
The general concensus is that the Caldwell rebuilds are the best around but from the UK it isn't a cheap option because of high postage to here and return postage for the exchange units.
Again general opinion is avoid run of the mill refurbs because when you look at the cost breakdown they can hardly afford to paint them let alone open them up.
And from my experience of NEW front shocks for a Sprite (from one of the main suppliers) the quality was terrible.
I can see why we go for the likes of Spax! Just allow say one broken tooth repair per 1000 miles in the cost calculations.
Graeme Williams

From what everyone is saying it sounds like the MGA does not need rear shockers?

Steve
Steve Gyles

AB, do you know if your rear leaf springs are original or replacement? The replacement leaf springs going back for several decades, are known for having too much arch, which screws up the ride height, the handling, and could easily make the ride harsher. Before changing the shocks, I would want to make sure the springs meet the original spec.

The usual recommended course of action in case of worn out original springs, or out of spec replacements, is to source a pair of originals that are in serviceable condition. Due to the dearth of MGA spares in Alaska, I ended up buying a pair of the out of spec replacements, and had a local spring shop de-arch them to the original specification. This, and making them look right ended up being a colossal pain in the ass, so I recommend sourcing good originals if you find that you need them. Barney has a lot of information on the rear leaf springs on his mgaguru.com site.

-Del
D Rawlins

This thread was discussed between 17/12/2015 and 21/12/2015

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