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Best new seat diaphragms?

Moss Motors
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Gerry Avatar
Gerry Gold Member Gerry Masterman
Prairieville, LA, USA   USA
Seat packings, installed properly, will not raise your seating height. There are/should be aluminum spacers that hold the seats up 5/8" or so. When I was making packings from 1/4" aluminum I made the spacers in the kit shorter by that thickness. The original wood strips just closed the gap between the runners and the carpet because the holes were larger than the diameter of the spacers

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JoeReed Avatar
JoeReed Gold Member Joe Reed
Cordova, TN, USA   USA
1978 MG MGB "Kermit"
In reply to # 3889176 by Gerry Seat packings, installed properly, will not raise your seating height. There are/should be aluminum spacers that hold the seats up 5/8" or so. When I was making packings from 1/4" aluminum I made the spacers in the kit shorter by that thickness. The original wood strips just closed the gap between the runners and the carpet because the holes were larger than the diameter of the spacers

So that means my 3/4" tall packings only make the seats about 1/8" or so taller than the original spacers/packings would have. Mine was missing packings and spacers originally. That's why I took the easy route of using 1x2 cut to the correct length and with the holes precisely drilled in the correct locations.

I wonder why the factory went with the option of 3 pieces per side instead of one simple piece? I don't see any advantage to the original method....




Gerry Avatar
Gerry Gold Member Gerry Masterman
Prairieville, LA, USA   USA
I've heard speculation that the true purpose of the packing strips was to provide jobs for the woodworkers that used to make the body frames for the T series cars. Using the alloy spacers and the wooden strips seem like a long way around the job to me

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Jwpotts Avatar
Jwpotts James Potts
Lexington, KY, USA   USA
1970 MG MGB
I rebuilt my seats 2 years ago with new foam and straps from Moss. One year later I stood up in the cockpit with one foot in the seat. I busted one of the straps. I think it’s cheap rubber. I’ve been told a cheap fix is to use a inner tube from a wheelbarrow and inflate 3/4 full. When I bought my car about 4 years ago it had a pillow stuffed under the seat.

geezer Avatar
geezer Silver Member charles durning
Magee, MS, USA   USA
1958 MG Magnette ZB "Chick Magnette (sold)"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT "Foghorn Leghorn"
When I rebuilt my seats I used the straps with the diaphragm. I find the seats to be more supportive that way.



"Whether you think you can do something, or you think you can't, you're correct"- Henry Ford

DrewM Avatar
DrewM Silver Member Drew Maddock
74 MGB roadster, Southern California, USA   USA
The seat straps Moss sent me when I redid my seats not too long ago were some other material than black rubber they used to use. I don't know what the material is other than "not black rubber," "very stretchy," and a lot better looking. Maybe nylon? More cloth-like than rubber. What it is I have no idea. Oddly, the picture of straps in the Moss catalogue still makes them look like the old black rubber straps. But maybe they just haven't changed the picture? I'm going to guess Moss was sick of bad rubber products failing.

Mine are much more flexible without being too stretchy. They feel a lot better than the rubber diaphragm without a doubt.

At first, I wasn't sure the new ones would support me well enough. So, along with the new straps, I added a couple of black rubber Moss seat straps I had lying around from a much earlier attempt. More is better, right? Mistake. After reinstalling the seats with both types of straps, the seats were waaay too hard. To avoid removing the seats a third time, I just reached under with some sharp scissors and cut the two black rubber straps under each seat and left them hanging there. You can easily tell the difference between the two types of straps just by feel. So fixing that mistake was easy. Thankfully.

The seats are very comfy compared to the old rubber diaphragm. They may be better than the rubber straps, but that's harder to say. I'm done with the old hard rubber diaphragms, that's for sure.

641-990
https://mossmotors.com/webbing-seat-cushion-include-hooks



Drew Maddock, So. Calif. USofA

MirrorTrim...Paul Avatar
Bedfordshire, Toddington, UK   GBR
We've been using webbing supports by Moss for many years for our rebuilt and exchange seats. The rubbers would fail and with the new nylon straps the stitching was so close to the cut end of the nylon it would fray and pull away under stress.

Two months ago the supply of these parts from Moss became difficult and the quality was so poor as a trim company we decided to manufacturer our own. We only make small batches at a time however it means we now have full control on the quality.

I suspect Moss will rectify there manufacturing issues in time, but for now were going to continue using and sell our own. Webbing supports will provide a softer seat and are ideal for those who are a little taller and need a bit more headroom. For those who prefer a firmer ride the diaphragm is certainly the way to go however retro fitting to a later type seat may require additional clip holes in the frame.

ingoldsb Avatar
ingoldsb Silver Member Terry Ingoldsby
Calgary, AB, Canada   CAN
1971 MG MGB
Quote: I've heard speculation that the true purpose of the packing strips was to provide jobs for the woodworkers that used to make the body frames for the T series cars.

The urban legend (that I heard) was that there needed to be some wooden parts in the car to allow members of the woodworkers union to continue working on the cars. Previous cars had much more substantial wooden components (in some cases, involving the frames). By throwing a few wooden strips into the car the rules were satisfied and everyone was happy.

I've never known whether this was the actual reason for the strips or just an urban legend. Lloyd might know.



Terry Ingoldsby
terry.ingoldsby@DCExperts.com

JoeReed Avatar
JoeReed Gold Member Joe Reed
Cordova, TN, USA   USA
1978 MG MGB "Kermit"
Interesting thoughts here, from using webbing AND diaphragms together, to simply preferring one or the other. I've got the webbings on the way from Moss...

One thing I may try is to provide a little support above the webbing (between the webbing and the burlap & foam. Since I'm replacing some of my carpet while the seats are out, I've got several good, used pieces. I'm considering taking the pieces that were under the seats and cutting them down to fit above the webbing. My thinking is that they'll provide some support by spreading the load just a bit among the webs. Someone mentioned maybe using pegboard, but IMHO that would be too stiff. The carpet with it's semi-stiff but still flexible backing might be just about right.

I'll do one seat like that and try it out. If it doesn't feel right I'll just yank it back out. Otherwise the carpet would be going into the trash anyway...

Having seen all the horror pictures of floorpans on this forum, I really appreciate that this car is so solid and rust free....not even any surface rust anywhere on the floorpans (original paint on them)....all captive nuts in place....




Captain Dave Avatar
Captain Dave Gold Member David Blakey
Clinton, TN, USA   USA
1967 MG MGB GT "Lil B"
1971 MG MGB GT "Cornbread"
The GT had plenty of wood in it. The spare tire cover is made of heavy plywood and covered with a vinyl pad and carpet. It is fabricated in two pieces with a rather industrial type hinge assembly. The Door Capping on the front doors is wood covered with interior matching vinyl. This is true on the roadster also. The rear quarter rails are also constructed of vinyl covered wood. The back support for the rear seat is also wood if I remember correctly. The woodwork is actually quite sophisticated and I'm sure took some nice tooling to accomplish. While interior trim plastics were in their infancy at the time, with production starting in '62/'65 it was probably about the best they could do with what they had on hand.

BTW, Moss asks $500 a pair for reproductions for the '62 - '65 roadster version. Less for later models.

Still I wonder, why the wood "insulators" under the seat rails? Maybe it was something the apprentice could do.

JoeReed Avatar
JoeReed Gold Member Joe Reed
Cordova, TN, USA   USA
1978 MG MGB "Kermit"
Well, that was fun! Got the webbings installed on the frames. Ordered them Monday from Moss.....delivered Wednesday (using the cheapest shipping option).

Installation would have been easier if I had screwed the frames down to the workbench, but got it done with the use of a couple of bar clamps and my big ass Harbor Freight pry bar. Looking forward to seeing how much better they feel....just gotta put the seats back together and install them, after first gluing in sill carpet on the drivers side.




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