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MG Midget and Sprite Technical - Moss uprated front springs

Has anyone fitted and/or use the Moss (TMG40901PR) 340lbs uprated near standard height front coil springs on a chrome bumper Spridget please?

I’m interested to know what difference in ride height these Moss (TMG40901PR) near standard height 340lbs uprated springs make?

20 mm drop is claimed - and I realise that it will vary from car to car

It’s very important to me as I already have fitted what was sold to me by a ‘specialist expert’ as 1” lower uprated 340lbs spring fitted with the claim from the l*eing b*stard that they’d “only drop the car by about half an inch” – the front is so low I scrape through exhaust clamps even the 1 mm thick ones
Nigel Atkins

Hi Nigel,

I have a few sets of 9.5 inch by 340lb spring sets brand new. These will lift the car slightly from standard height and will stop the car diving under brakes as much as standard. They are a great spring to drive on and really take abuse. If you are interested email me.

corry dot will @ gmail dot com

cheers
will
WDT Corry

Nigel
I'm confused...standard ride height springs, should be just that, the spring rate is irrelevant to ride height. The sprung weight of the car makes a difference to the ride height for any spring , but IIRC yours is all standard in that department (bumpers fitted, no lightweight panels)
I have a set of 340lb std height springs you are welcome to try on your car if you want to experiment with them.
Ian
Ian Webb '73 GAN5

Will,
thanks for the info I'll bear it in mind I don't have too much trouble with dipping under braking

I don't want or need to be too much off standard ride height but possibly have to allow for back springs saging (under cabin weight)

standard height spring were/are around 9.85", 271lbs

my car is strict road only use so finish and durability is important - I wont be swapping them every other weekend to siut there use at that time

I'll email you for photo and details thanks
Nigel Atkins

Nigel it would help if you differentiated between standard height and standard length; height is usually taken as ride (running) height after fitting to a standard weight car.
David Smith

Hi Ian,
thank you very much for your offer very kind and practical

I wont take you up on it as I loave doing any work on my car despite how it might seem to others and I have to do the work outside on my hardstanding so I'm fed up with just getting all my tools out for it to start raining and then stop seconds after I've put them away, so I prefer that the jobs are repeated as few times as possible

I would be interested in a photo of them with a tape showing spring height though if that was possible

I know what you're saying about ride and spring height but the Moss ones say they'll drop the ride height by 20mm - now that's not far of 25mm

the '1" drop' ones I have fitted certainly looked like they dropped the front lower than 1" let alone halfof that , which changed to "I said half to three quarters of an inch" when I commeted at collection but I didn't take any before measurements I could only say it looked a lot lower

the springs were fitted as part of the front and rear suspension upgrade but the 'specialist experts'

I was told by them there were problems with the first set of replacement rear springs which I never saw but the springs now on the rear appear fine

based on their other work and my dealings with them I've no idea if the front springs fitted were as I asked for - the handling at the front is fine just too low - or even if there ever was any problems with the rear springs

I wont even go into their leaking gearbox, rattling lever or poor work on shortening gearbox and badly altered clutch mechamism

I've decided to replace the springs now as the new steering rack and replacement TREs fitted only last August have split and cracked on their rubbish rubber covers

plus I've run out of patience at having to go slower on the types of roads I like
Nigel Atkins

David,
thank you now I know the convention of description I will try to stick to it

the original sales brochure for the springs I have fitted has '1" lowered' which is why I stressed before purchase I told them that I go over bumpy roads and didn't want the car too low or harsh riding

I remember well being shown a dark blue Spridget that had the kit fitted and went "touring all over the roads of Europe without problems"

it also had the most comfortable armchair style seatts I've ever seen fitted to a Spridget

my invoice had 'Springs lowered by 1"- free length 9" - uprated to 340lb'

perhaps it's something to do with the way they are fitted but I can't think what or they're 9" or 340lb but they seem well controlled
Nigel Atkins

Nigel,

If you only bought some of that stuff last August, aren't you claiming warranty on them?
Lawrence Slater

Lawrence,
replacement steering rack gaiters have already been sent to me and the TREs will be refunded I'm pretty sure of that but I don't want another rubbish set from the same stock so I have to risk buying from elsewhere where I'm told the rubber looks fine on the TREs and that they've had no (reported) problems with them - no doubt by the time I get them they'll be on the rubbish stock too

what hacks me off is the replacement parts don't magic themselves on as replacements and the units haveobviously already been fitted to the car

plus the prevoius TREs were only a couple of years old and I ummed and arrrred about having them on the new steering rack but decided to replace with new just in case

the sh*t oufit that done the spring I went back to with other problems of their work and realised the guy's a conman and with hindsight I came to my own conclusions as to what might have been going on but the dodgy repairs and fixes made me realise that it was best not to further call on their style of warranty work

sometimes you're better to to accept your loss and not add to it - if they do a poor job when you're paying them these type of people don't improve the quality of their work when they not getting paid (as they see it)
Nigel Atkins

Nigel,

I would think Wills springs sound ideal for your needs, after installing them you can just add spacers between spring pan and wishbone if you want the car a bit lower? It's much easier to lower the car than raise it?
Andrew F

Hi Andrew,
yes I've sent Will an email enquiry

you can put spacers in to lift the ride height but not by very much at all

spacers to lower are easier but I'm not keen on doing this unless I really have to

I only enjoy driving the car not having to adjust or replace parts because they've only lasted months instead of years or because the wrong part has been fitted

I'm in my 5th year of ownership and I've done, or had done, quite a lot of work on the car and had to redo a lot more of the work already done than you'd imagine because of poor quality parts or wrong parts fitted

that's apart from the regular servicing work and changes to get the car how I want it

I probably wouldn't be quite so reluctant if the previous car hadn't been such a nightmare experience and severe money pit
Nigel Atkins

Nigel, What is the measured ground clearance on your car now with the "lowered" suspension? Standard was listed as 5" ground clearance for a MK3 MG, so given that your car is near standard that should give you a known starting point. The only thing - I don't know where the factory measured this ground clearance at, do you? Presumably the lowest point, which would be the exhaust.

Free spring length for your car is listed in the Owners' Manual as 9.59" so just slightly less than the figure you quote of 9.85"

Increasing the spring rate from the standard of 271 lbs to 340lbs will reduce the suspension travel over bumps (that is, not the overall travel, but the amount it compresses for any given force applied to the spring) So stiffer springs without change to their actual free length would give better clearance on uneven roads, potholes and speed humps etc. But the stiffer spring will also give a slightly raised ground clearance when "static". This is because it doesn't compress quite so far with just the weight of the car. It is normal to supply a 9" free length spring when uprated to 340 lbs, which should then compensate for the increased stiffness and more or less maintain the same static ride height. Anything shorter than 9" will certainly lower the car, very roughly in the ratio of 2 : 1 i.e. a 1/2" shorter spring would lower the car by roughly 1", although the ratio isn't linear and is complicated by varying spring rates.

In my experience, sagging rear suspension actually doesn't seem to effect the front ride height at all. Most "variable load" is taken by the rear suspension, and even carrying a lot of extra weight seems to have little impact on the front ride height which is dictated by the weight of engine and front bodywork etc.
Guy

It just occurs to me - if you are having problems with the exhaust pipe, what condition are your engine and gearbox mounting rubbers in? Maybe the engine is sitting low in the body, or twisting on its rubbers, so lowering the exhaust pipe at the front bend below the manifold?
Guy

excellent summary Guy.. I was going to write on the same theme but it would have been twice as long and not so clear!
David Smith

Hi Guy,
thanks for your comments they are genuinely appreciated

yes all say 5” ground clearance, for how low mine is let’s do it this way, from the road test done by Motor in May 16th 1964 on the Mk2 midget they show the ground clearance as 4¾” under exhaust pipe and 12¾” from bottom of door to ground, so if we add a ¼” this gives us 13” – mine measures just about 12”

I don’t know what ‘Owners manual’ you refer to Guy but it is wrong, if it’s an aftermarket general publication like Haynes then as I keep saying it has errors – Driver’s Handbook is the only accurate publication I’ve ever read on the car

standard springs CHA 129 are 9.85” free length

your explanation of spring rate was how I thought I understood things originally and I know what you mean about rear springs but you’re probably not loading 25 stone in the cabin and a week’s worth of underwear in the boot :)

I’d considered engine mounts but they are the same as when the previous standard springs were on and I asked for them to be checked when the engine and gearbox had to be taken out by a reliable garage to put right the poor work of the cowboy outfit ‘specialist experts’ – the 5-speed gearbox conversion, along with other faults and poor work, had been fitted too far forward so that a road side emergency fan belt change was made very difficult because the gap between the pulley and chassis cross member was less than the smallest profile of the fan belt

so no unfortunately it’s not the engine or gearbox mounts

until I remove the springs fitted I don’t know if they are really 1”, 340lb as the l*eing b*stard told me they were – also why say they drop the car by ½” and then later ½” to ¾” – bear in mind the whole front and rear suspensions were being ‘upgraded’ with the springs as part of this

perhaps I have 270lb, 1" lower ride height springs or they're originally described but badly made or something with the fitting (but I can't think what)

I was put off collecting the car on the agreed collection date as I was told by the other LB that they had a problem with the rear springs, that they sat the car too high at the back and were too stiff - by the time we got the message we were only 20 miles from them but at that time I had no reason to distrust them so we didn't go there, I wish now I went there and perhaps caught them out but that's life, if I didn't think I could trust them I wouldn't have left the car with them - another error of judgement

below is an out of focus photo of standard springs CHA 129 but you can see the tape


Nigel Atkins

Nigel,
The spring length I was quoting was from official Workshop Manual (BL Facsimile copy, not Haynes) so I doubt that it is wrong. However I see that it does also state that the late MK 3 Midgets from GAN-5 123837 onwards, had the 9.58 " springs.
I don't think that the Handbook gives the spring length, just ground clearance as 5" Not 4 3/4" as in the Motor road test - I thought you always believed the Handbook above all else?

Beyond the suggestions I have made, I cannot help further
Guy

Nigel,

Haynes quotes later models spring free length as 9.85", the same as you are quoting.

So Haynes is correct then?
Lawrence Slater

Also, where does it say 20mm reduction in ride height for TMG40901?

All I can find is this. And it quotes the same TMG40901 for both RB and CB, with a different height reduction.




Lawrence Slater

Guy,
I appreciate your help I was just trying to get the facts right to help me, you and others

as I didn't make it clear I think you misunderstood what I meant, the ground clearance for my year and model is 5"

I quoted the Motor Mk2 test as it was the only one to have the information 'ground clearance 4¾” under exhaust pipe' as this answered your question of where the measurement was taken from

my car is 5" so that's why I added the ¼” to make the 12" measurement more accurate

I believe in the Driver's Handbook so much as it's the only accurate book I've read on the car (and you are proving it here)

if your Workshop manual shows 'that the late MK 3 Midgets from GAN-5 123837 onwards, had the 9.58 " springs' then it is a typo as Lawrence has already put it's 9.85"

from Workshop Manual AKD 4021 (15th Edition) from the DVD I always suggest - http://www.rimmerbros.co.uk/Item--i-HMCC3009DVD

Free height 9.85” (25 cm)

(and shows 18 cm when fitted)

(General data 19 – Sprite and Midget – Issue 5 – 86124)

from page 133 of Terry Horler's book –
'The front suspension was carried over from the 'round-arch' Midget but at GAN6-171478 (January 1978) the coil spring free length was increased from 9.85" (250.2 mm) to 10.2" (259 mm)
Nigel Atkins

I have an original BMC workshop manual which quotes spring free length for early models (948cc) as 9.4" (23.8cm) and ground clearance as 5" (12.7cm).

For Sprite mk3 & Midget mk2 it gives spring free length as 9.59" (24.4cm).

It doesn't show any change in data for the Sprite Mk4 Midget Mk3.

Dave O'Neill2

Lawrence,
the two different copies of Haynes that I’ve got are NOT correct

they update the publish date but not fully the contents to that publish date

1974 issue – nothing in the Chapter 13 Mk3 Supplement but on page 144 for the Mk2 shows Free length - 9.4 in. (23.8)

1982 issue – page 214, Mk3 (except 1500 models) – 9.59” (244 mm)
Mk3 (1500 models) – 9.85” (250 mm)

so, NO my two copies, at least, of Hayes are NOT correct



that info from Moss is more than they put on their website which is where I got the 20 mm from – ‘a uprated road/competition spring with a reduction in ride height of 20mm’

http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=1609
Nigel Atkins

Hi Dave,

I'm not imagining this or misreading it, I can't print it off or scan it as it's on the protected DVD so you'll just have to take my work for it -

from Workshop Manual AKD 4021 (15th Edition) from the DVD I always suggest - http://www.rimmerbros.co.uk/Item--i-HMCC3009DVD

Free height 9.85” (25 cm)

(and shows 18 cm when fitted)

(General data 19 – Sprite and Midget – Issue 5 – 86124)

ETA: no date but says it covers up to Sprite MkIV and Midget MkIII up to and including Car Number GAN5-153920 (1974 Models)

right just found it, it was published 1973
Nigel Atkins

Nigel,
My mistake in typing, I transposed the last two digits in my last message. Sorry!
Official Workshop Manual gives two spring lengths for the MK3 Midget. Early cars - 9.59" and late cars 9.85". My Handbook (MK 1V Sprite) doesn't quote either.
Changeover for the spring length is given as car GAN-5 123837. What number is your car?

In many ways, this is probably not relevant or helpful as you have already had your springs changed over so you are starting from a different point anyway. What is right for your car is what suits you, your driving style and where you drive. Nothing more really matters, does it?
Guy

No worries Guy I’m Kung of Typos

My car is in the RFL paying number up in 130,000s

There is a bit of relevance as I had new standard ride height and rate spring fitted for two years before the current suspension set up (uprated recon lever arm damper were put on very shortly after I bought it as they were about another £1 over standard)

I can’t remember the exhaust suffering so badly with the previous springs and suspension so it has to be from my ill fated work done by the cowboy out fit of ‘specialist experts’ or the springs they used

With Lawrence posting that photo of I guess the Moss catalogue their spring range now makes more sense, trying reading their web site and being certain about how many and what uprated springs they do

TMG40901 340 lbs, slight height reduction (fast road) drops the front 20 mm I believe but MSG40906 400 lbs is at standard height but is described as fast road/sport

now I know these things aren’t linear but 340 lbs is a roughly 25% increase where as 400 lbs is nearly a 50% increase over standard plus the description of sport suggests more semi-track – would 400 lbs make things too ‘stiff’ at the front for the roads I like to drive on, also bearing in mind my rear springs are standard

perhaps I need to start a new thread asking that from those with that rate of front springs
Nigel Atkins

I would be a little wary of the Moss catalogue information.
The reason is that according to their figures, the same two springs used on the 1275 and 1500 cars seem to respond in different ways for the two cars.
Note that the stiffer 400lb spring gives a slightly higher ride on the 1275 car than the 340 lb spring. It is what one might expect if they were the same length, but different spring rates.

Then look at the effect of the same two springs on the 1500 model. The stiffer spring this time gives a greater reduction in ride height. Something must be amiss with their information. One might expect both springs to give a reduction in ride height compared to the standard 1500 springs which are longer. But why would the stiffer spring reduce the height by more?
Guy

Yup Nigel, I scanned my moss catalogue, published feb 2004, but also found the same info in several other places.

My Haynes (Pub 1977), also gives the "early" spridget models as spring free length of 9.4", but doesn't define early and late to years.

Also Nigel, if you want to paste something here from your protected DVD, just get it on your screen, and then press the PrtSc key on your leyboard.

-- You may need to use the shift key to do this.

That will load the page into the clipperbopard.

Then open paint (or similar), and on an empty screen use edit/paste. This will load the clipperboard of your copied DVD page, into paint, or your chosen program.

Then just do a save as xxxx.jpg

From there you can upload to here or anywhere you like.
Lawrence Slater

This thread was discussed between 07/02/2012 and 08/02/2012

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.