Car seat base

[mikecg]

Hi I did not get a reply when I called it a diaphragm but I am now calling it a seat base. The rubber seat base that has hooks and supports the seat cushion.
Any thoughts on a replacement or alternative method of repairing the seat?

Ta Mike

[dapinky]

Mike,

It all depends on if you are looking for a DIY 'fix' or an OE solution......

..... the rubber diaphragm (C100U0117F) hasn't been available from Lotus since 2007 when they sold off their stock of them for a tenner each, so unless you can find one on a shelf somewhere, it is unlikely that you will be able to replace it with a new item.

Second-hand may be an option, but condition will be unknown.

If it were me (and I didn't have any way of using OE parts), the choice is to use the old one as a pattern for an upholsterer to recreate one, or use something else.

I have seen someone use a piece of 9mm or 12mm plywood slotted into the frame - this is a bit springy and is reported to work well.

The S2 uses a metal (sheet steel) seat base, so a piece of steel plate of a suitable thickness could be an option - I suppose it depends on what weight it needs to carry. My 110Kg would need something more substantial than a 70Kg driver.

[Jamie N]

Another option is just to get other seats, lots of possibilities these days, S2K ones are nice, or MK7 Celica, plenty others, many far nicer, better constructed and more ergonomic than
the originals if you are not too fussed about originality.

[Tuga2112]

you can fabricoble your own replacements as well

i got a sheet of rubber and 4 strips of 2mm thick metal a handfull of bolts and fence wire.

cut rubber to correct size, drill plenty of holes along the strips clamp it between metal strips. half the holes will be used for the bolts to clamp the rubber. and the other half is used to thread the fence wire to attach to the places on the seat where the springs used to attach.

i have a couple o pictures somewhere. but cant find them sadly... im sure in a couple of months time they will turn up

[mikecg]

Thanks guys, some very useful ideas to consider. When I bought my M100 the cockpit had been completely re-upholstered and is still looking very good so keen to keep it all matching. The rubber or wood options sound potentially the easiest to execute.

Mike

[Tuga2112]

[mikecg]

Much appreciated

[wayne]

Mike, I have a new OEM seat diaphragm available if you want it, unfortunately I paid a lot more for it than the £10 that they may have been sold off for, I really do not remember how much I paid for it but If you want it you can have it for £50 plus shipping. I think that this is roughly what it cost me.

I also upgraded mine to an Aluminium base that I made, I think that I posted details on here a few years ago if you can find the post. Sorry, I dont remember how to attach pictures. PM me if you need pictures and details.

If someone could find the post for the aluminium base it could be helpful. I also sent the details to SJ Sportscars and I think that Steve remade them.

[RonR]

The only 'seat diaphragm' thread with your contributions appears to have been lost in the ether - HERE

I have a pair of the SJS ones ready to fit, didn't realise they were to your design, Wayne!

[mikecg]

The only 'seat diaphragm' thread with your contributions appears to have been lost in the ether - HERE

I have a pair of the SJS ones ready to fit, didn't realise they were to your design, Wayne!

Ron, how did you get on with the SJS seat base kit, I must do somthing before the new driving season. I have slide a couple of large books under the seat to keep it firm.

[RonR]

I've not got around to fitting the seat base kit yet Mike, still using the Porsche seats at the moment.
I also have a seat heater kit ready for the job so I must get on with it soon!

[wayne]

The only 'seat diaphragm' thread with your contributions appears to have been lost in the ether - HERE

I have a pair of the SJS ones ready to fit, didn't realise they were to your design, Wayne!

I gave the dimensions to SJ's as I had no interest in making any more. Think SJ's went with self tapping screws and I used pop rivets as it what I had available. Other than that I think that they are still the same. Material may be slightly different as I used aircraft grade aluminium.

I have not yet fitted the PAX seat one on my car yet as it hasn't failed and I don't sit in it, so I still have the spare one but its not for sale.

The seat difference is amazing. It's well worth the upgrade.

[mikecg]

The only 'seat diaphragm' thread with your contributions appears to have been lost in the ether - HERE

I have a pair of the SJS ones ready to fit, didn't realise they were to your design, Wayne!

I gave the dimensions to SJ's as I had no interest in making any more. Think SJ's went with self tapping screws and I used pop rivets as it what I had available. Other than that I think that they are still the same. Material may be slightly different as I used aircraft grade aluminium.

I have not yet fitted the PAX seat one on my car yet as it hasn't failed and I don't sit in it, so I still have the spare one but its not for sale.

The seat difference is amazing. It's well worth the upgrade.

I have just received the SJS seat upgrade kits which are to be riveted. I need to buy a cheap rivet gun but other than that I have no instructions. Wayne can you offer any advice/tips etc. I have the seat out and can see the split diaphragm and its clips.

[mikecg]

I've not got around to fitting the seat base kit yet Mike, still using the Porsche seats at the moment.
I also have a seat heater kit ready for the job so I must get on with it soon!

Ron I have received my seat "Conversion" kit from from SJS but it is far from straightforward as to how it is to be installed and SJS provided, only after asking, limited and far from complete. I have written to them with some quite significant requests as it appears you have to carry out not insignificant modifications to the frame and the S/S plate to install.
I know they have copied Waynes design but this is their product now and hopefully they can support how to use the "Conversion"

[mikecg]

Has anybody installed the Seat Base Conversion that was designed originally by Wayne but now manufactured by SJS.
I would love to discuss how the installation was achieved. Thanks

[wayne]

After speaking to Mike today there is a significant flaw in my design that I passed along to SJ's. Anyone thinking of buying one should put it on hold for now.
I have ideas on how to fix it but would welcome ideas from the rest of the forum. I have no intention of remaking these parts and passed the idea over to SJ's who currently offer kits that don't fully work and offer no fitting instructions. Please don't blame them, it"s probably my fault for giving them a design that my trimmer fitted and didn't tell me that they made modifications to it.

[mikecg]

I have now successfully fitted one of the SJS conversion kits which I am absolutely delighted with. The kit is great quality but comes with no instructions as to how to fit it. Without significant help from Wayne and Ross at SJS i would not have been able to complete it. It is not at all obvious.
I have taken lots of pictures and will try and put together a PDF to help others. Once I knew what the do it was pretty straightforward and did not take very long and the finished installation is amazing.
I think Wayne is being a little hard on himself. The conversion kit design works well but Wayne did not install his, he got an upholsterer to do it but was able to see how it was achieved. There is more than one way to indtall it.