Triumph Repair: TR7 Seat Foams, frame rail, steel seat

Question

foam rib   QUESTION: Howard,

  You gave me great tips on seat rebuilding in December, I got sidetracked on door repair but now I'm back to the seats.  Have you ever has a problem with the sizing of new seat foams ?  My new seat back foams appear much larger than the original in some dimensions.  Along the top of the back foam - where the hole for the headrest is, the new one is 19 inches wide, the original is 17 1/4, and when placed on the frame it sticks out noticeably at the top.  The new seat cover appears the same width as the original.  Also, the foam rib inside the side panel that fits just behind the frame rail that forms the side bolster is much further back and interferes with the mail seat back rail.  I've attached a photo, my thumb is on the old foam rib, small finger on the new.  I'm tempted to cut and re glue - or am I missing something ?

  Thanks,

  Steve

ANSWER: That "Ad on" rib fits behind the small steel bar (which is your lateral support in turns) and in front of the main steel seat back bar and I found them glued to the main bar in some cases. I have never purchased any of the new foam as I have been able to reglue the foam that had come loose. I would have much preferred to see BLM make a one piece foam back but the British manufactures have always made things out of several pieces when they could make it in one piece.
Are you saying that the new foam is only pieces and not a complete back? If it were mine I would assemble all the foam and if it is too wide or too large, cut a piece out and reglue it. That's if the manufacture won't correct the problem.
Howard  

---------- FOLLOW-UP ----------

QUESTION: Howard,

  The back foam is several pieces glued together, it's the position of the side rib that is the problem.  Interesting you mention you have seen this rib sometimes glued to the main frame rail, that's where it seems to be positioned but if I glued it to that rail, the seat would be too wide for the seat cover.  Maybe that is the design, since the top piece is almost 2 inches wider than the original.  I think the foam may have been made for several car seats - maybe a Dolomite seat was wider ?  Anyway, it will be a lot easier for me to cut and glue than to ship it back, but I will have a talk with the seller.

   Thanks,

   Steve.

ANSWER: Taking the seat apart I noticed that there was some glue in that area. It was not glued to the rail then the rest of the foam added. The whole completed foam back with the side boards attached was one piece and a small amount of glue held the whole unit in place as they covered it. I have not had all the years of TR-7 seats apart so I don't know if they made any changes in the foam. I do know that they changed the covers as I had at one time, 5 TR-7s, of 74 to 77 models. 4 coups and one roadster. One of the coups I modified to run on Ethanol Alcohol in a grant I received from the DOE. Story is on my web site. http://mg-tri-jag.net/alcohol_fuel.htm
I did not have the need to take all the seats apart so I don't know what was inside all of them.
You might research some seat parts to see if all years have the same part numbers. I just know that the seat covers were different.
As I told you I am building a set of "7" seats for my MG V8 conversion but I don't remember what year TR-7 they came out of. I believe it was a 76 model. There were a lot of changes made in 77 but I don't think the seats changed only the covers.
Howard

---------- FOLLOW-UP ----------

QUESTION: Howard,

  I cut the foam ribs off and re glued them more forward to fit between the front rail and the main rail just like the old foams.  I also cut away some of the width across the top and pulled the sides in to better follow the frame.  The seat cover fits good, I'm going to glue the foam to the frame, apart from pulling in the flaps tight, have you ever glued the inside of the seat cover to the foams to better follow the shape ?  I was thinking of gluing along the inside of the side bolsters of the seat bottom foam to get more of the 'bucket' shape.  I'm also going to try your suggestion of pulling the flaps through the holes in the diaphram.  The problem with the vinyl covers is they are thick and stiff and just want to flatten the foams...

   Thanks,

   Steve.

Answer
I only pulled the added inside flaps through to make them pull in and did not glue the covers to the foam. I have finished one seat and am working on the other now. On the bottom I laced heavy cord through the flap and run the cords down through the foam and through the holes in the seat diaphragm to pull the seat bottom down. Some other cars do it that way. The back on the one I did is just pulled through the foam and glued like the original was but I am not satisfied with how it looks so on the second seat I am going to run a heavy cord across the back between the rear side rails and attach the flaps (which I cut into several thinner flaps) so as to bypass the back webs and each will be secured to the new cross cord. I think that will draw the center of the back in more than attaching it to the foam which I don't think the foam has enough rigidity to hold the center back in. I had a trim shop custom make my seat covers and I am installing them. I wanted colors to match the color scheme of my car. If my second seat back looks better I will open up the first and do it the same way. I document just about everything I am doing to my car so if it works I will post a few pictures of the seats on my web site.
Howard