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MG MGA - coupe seat cushions

I just finished refurbishing the seats for my coupe. They turned out pretty nice but I had a bit of a surprise when I first sat in the car. The bountiful headroom is gone! The seat sits a LOT higher than it used to. I even had to adjust the steering wheel out so it wouldn't rub on my right leg. I know the seat is sitting in the frame the way it should and I also got the cover on nice and tight. The cushions couldn't/shouldn't be any more compacted than they are. I ordered the cushions from Moss and they said they were interchangeable between coupes and roadsters. Now I kind of wonder.

Has anyone else ran into this issue? Just curious.
P.R. Fahey

I had the same exact experience. I have not yet solved this dilemma but have several ideas.

If I am not mistaken, the original seat foam was not a solid piece but instead had a regular pattern of holes in the central area of the undersurface. It seems that these holes were 10 to 15 mm wide and probably 50 to a 100 mm deep. This allows you to sink into the center of the seat. Am I dreaming this or was yours also like this. This may be the difference in sitting height that we have found.

So, I am looking for a source of holy (couldn't resist) foam. Either that or coming up with a cylindrical device to cut similar holes in the bottom of the supplied foam block.

Jon
J.T. Watson

The foam you're referring to has been taken off the market because it would feed a fire ( the holes would allow the whole cushion to combust)
You might find some at an old upholstery shop, but I doubt it.
mike parker

I have some (used) original coupe seat foams and they have the holes you mention. I'll try to get some pictures/measurements if you like.

Neil
Neil McGurk

I have a 1600 roadster and a 1600 coupe and the cushions in the latter are much lower (just ask my comparatively diminutive wife who has trouble looking over the dashboard!). Both were trimmed by a (now deceased) very experienced trimmer.
Barry Bahnisch

I also have an original set of roadster cushions from which I have not removed the covers yet. It will be interesting to compare.
Neil McGurk

Neil,

Images and measurements of your seat cushions would be helpful.

Jon
J.T. Watson

I have an image of my roadster seat taken during the rebuild. I would find it odd if the seat squabs were different between the roadster and coupe. There is so much more headroom in the coupe to begin with. I checked my parts book and P/N for the seat frame bottom is combined with the back so there is no way to compare P/N#s of the base.

The original cusion is obviously made by pouring the foam into a mold. There is a number in the foam. One of my cushions reads "TYPE AO3298" on the side of the foam.




C Schaefer

My old seat cushions also had the cut-outs. I wanted to reuse them but they ripped apart because they were stuck to the upholstery. Had I known what I was going to experience with the new seat foam, I would have kept the old foams and tried to make them work. This new seat foam has totally changed my driving experience in the coupe. I don't like the position that I have to have the steering wheel. (too close) And I miss the feeling of sitting on top of the road. I will probably take the covers off and try to trim the foam. To me, it's that bad.
P.R. Fahey

Gentlemen,
I re-built my coupe seats a couple years ago using Moss upholstery. I have to say that I did not experience the dramatic difference that several of you describe. The seat cushions, to me, fit and feel fine. I'm about 5'10" and weigh about 190. The old cushions had been recovered many years ago however. I had the covers made at an upholstery shop. They were installed right over the old covers and had some additional wadding. Perhaps that's the difference. I'm about to do the seats in my roadster. The cushions are so flattened they sit very low. I'm always finding little bits of dried-out foam underneath.
Regards,
Gerry
G T Foster

I don't know if this will help, but, in the MGA Handbook, on page 13 there is a profile view of a coupe the shows exterior and interior dimensions. For the seat cushion it shows the following:

Height (highest front part) is 7 inches
Depth is 20 inches
Width is 17 inches

There is not a comparable list for the roadster.

Regards,
Gerry
G T Foster

I used the new foam from Moss. It didn't have the holes like the original foam did. You sit "on" the seat, not "in" the seat like the old ones. It's a little like sitting on a bar stool and trying not to slide off the side. I am seriously considering dissassembling the bottom cushions and cutting some sort of relief holes in the middle of the foam to allow me to sit in the bucket seat that I remember from 47 years ago.
Ed Bell

C Schaefer is absolutely right. Coupe and roadster cushions were identical. The hole diameter is about 1 3/4", but it should be noted that the moulding allows a "skin" around the surface and so the compression characteristics would not be replicated by cutting an open cell foam.


Neil McGurk

Here are the holes, (which I believe are still available seperately.)

LOL Neil


Neil McGurk

NOS holes or repro,Neil?
LOL Gary
gary starr

The old cushion squabs are made of Latex, and they rot with age. Mine left the floor looking like it was always covered with sawdust, and they were not very comfortable.

When I first fitted the Moss replacement cushions they were much too high, so I removed the covers again (with a blue cloud over my head) and took a normal wood saw to them to trim them significantly down.

After that the original seat covers (and I do mean original) were an easy fit, and the seat was much firmer and more comfortable than before.

Remember that if you have original latex bases, they are probably nothing like they were 50 years ago in terms of the support that they offer. Using modern closed cell foam is going to change the feel of the seat dramatically compared to what was there before. If it's too hard or too high, use a softer foam or less of what you have. The bases are also nothing that you couldn't make yourself using standard foam and a sharpknife (or a saw !)
dominic clancy

Best way to cut foam is to use an electic knife like this-
http://www.cooking.com/products/shprodde.asp?SKU=178660
If the Mrs already has one don't let her catch you using it,to them it's just like when they borrow our tools!
gary starr

My wife doesn't own an electric knife and has a tough time even finding the kitchen. (I'm safe. She'll never read this.) I was able to fix my seats using a regular wood saw. I took the cushions out on the deck to cut. Good decision. Quite messy. Anyway, just using a regular hand saw, I cut off just the square part on the bottom. You know, the part that is SUPPOSE to fit in the little basket but doesn't. I then used scissors and trimmed the piece that I cut off so it would fit in the bottom. My seats are now very acceptable. Maybe a tad taller than the old cushions but not annoyingly so.

Thanks for all the responses.
P.R. Fahey

Ahhhh! Your replacement cushion wouldn't fit in the basket? That is the root problem. Sounds like the replacement cushion materials were OK but the craftsmanship was a bit lacking.

Glad you got it all worked out.
C Schaefer

Who says I would never read this......

Just wait till you get home.



f fahey

Good one, Mrs. Fahey.
P.R. Fahey

At the risk of offending somebody, I am amazed at the number of "correspondents" who do not know what they are talking about! I have both a 1600 roadster and coupe, both restored nearly 30 years ago from very original cars (and subsequently multiple prize-winners- I only added that to show that they are not "lash-ups") and the headroom in the roadster is about 3 inches higher than the coupe! The seat cushion in the coupe is approx one inch lower than the roadster which no doubt was to compensate for the reduced headroom.
Barry Bahnisch

Hi Barry,

Very interesting. I have both coupe and roadster seat bases that still have their original factory covers (and foams). One of the coupe bases is shown in the pictures.

I have not yet taken the roadster base apart and my comments rely on the other photo and information kindly supplied by C Schaefer.

I can also measure the cover sides as an additional indication of the original base height, although I would expect some variation there due to both original fitting and age.

I shall report back shortly!

Do your cars both have there original foams and covers?

Neil
Neil McGurk

Barry, your comments are well taken. My statements are based on my personal experience as I have owned a coupe and a roadster at the same time. I only have the roadster now. At the time, the coupe was well worn and the roadster freshly restored. The differences in seat "cush" were obvious. Very much so. But in my small sampling the headroom was noticably better in the coupe. I had no other reference point to go by.

I tried to find any quantitative data from "back-in-the-day" to support either position. I had thought I read some years back about the coupe being taller but I must have been confusing it with the MGB. I searched my reference library and the Internet. The only "data" I have found is a side view of the Twin-Cam roadster with some dimensional data. That document stated the OAH with the top up is 4'2". I also found other data elsewhere that the MGA coupe and roadster were both 50" OAH. So from the outside of the car, they are (or shall we say, were when new) both the same OAH. Obviously the distance from the floor to the ground would be the same for both. Inside, the differences in Interior headroom can only be accountable to 1)seat cushions; 2)coupe headliner gap; and 3)whether you measure to the convertible canvas or the the top frame member. Granted the headliner may take up more room than the frame. All other things equal, would make the roadster headroom slightly higher if both seat bottoms wered the same. If, as you say, the coupe's seat bottoms were lower, then this may negate the differences.

Neil's cushion photo from his coupe with the moulded P/N matches the P/N in the cushion from my roadster. Was mine seat bottom originally from a coupe and found its way into a roadster? I cannot say for sure; 53 years is a long time. When Neil looks at his roadster seat bottoms, we should know more definitively about the seat squabs. Until we find better historical info, I stand corrected that the coupe has less headroom than the roadster.

Chuck

C Schaefer

I only have a roadster so I have lttle to offer this discussion than to quote the Coupe headroom (top of seat to roof - item D in photo) as given in Olyslager's MGA Coupe & Roadsters. The measurement is 37 inches.

Steve


Steve Gyles

I should have added that item E (height at the top front of seat above the floor) is 7 inches and overall car height is 50 inches.

Just measured my Roadster seat. Floor to piping is 6.5 inches, although mine is a rebuilt seat using a kit supplied by Bob West.



Steve Gyles

Looking at the original road tests in "The Motor" they give the following. The open car was tested in 1956 and the coupé in 1957.

open coupé
seat to roof 37.5 38
floor to roof 42 41
floor to cushion
(front) 6.5 7

I would suggest these are all within limits the same.

Does anyone want any other figures?

I'm now hoping my table will look OK after transmission.
Malcolm Asquith

Its taken the spaces out of my table. The first number after the definition is for the open car and the second for the coupé. The last line of figures refer to the front edge of the seat cushion.

The overall height was given as 4ft 2 inches for both cars. The tyre pressures were 17 front 20 rear for both cars using Dunlop 5.60-15
Malcolm Asquith

I found the Autocar road tests on http://www.mgaroadster.co.uk/
You can look there for the articles. They have the 1500, 1600 and Twincam (1958 1500 style w/ competition seats). Their results are:


car OAH headroom seat cushion height
1500 4'2" 34-1/2 6-1/2
1600 4'2" 36 7
TC 4'2" 37 8



From this, Malcolm's, and Steve's data, I think we can conclude that the measurements must have been made with a rubber tape measure and cannot be used as absolutes. The accuracy at best is within 3 inches!

Chuck
C Schaefer

Well, I have now stripped down the roadster seat bases and the foam is exactly the same as the coupe seats! So indeed the coupe and roadster did have the same seat base cushion foams. Dunlopillo Type AO3297 and 3298 for LH and RH.

But, the coupe cover was glued to the seat foam across the front seam, whereas the roadster had (a small amount of) wadding on top of the cushion! This gives a different profile on the seat cushion and would have made the roadster cushion (very slightly) higher.

Barry, maybe the CKD cars in Oz used local cushion foams? (i.e. were trimmed locally) with different types for coupe and roadster.

Neil
Neil McGurk

For those like me who like numbers, here is the complete key to my earlier post.

Steve


Steve Gyles

Given the interest that this topic has generated, I have removed a cushion from each of my cars. The coupe seat foam appears original (having had a comparatively sheltered life in the closed car) but I am not sure about the roadster (which was, as suggested, trimmed here in Oz). The coupe seat is definitely lower all around, and if, as has been suggested, the foams were the same, perhaps the trim shop took a thin slice off the bottom (rather than tool up for a thinner foam for the relatively low production). I think that the factory must have been anxious about the coupe seat height and this may account for the styling change, the longitudinal roadster pleats would have had a tendency to gape if the cover had been pulled down tight.
Barry Bahnisch

This thread was discussed between 26/02/2009 and 07/03/2009

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