Let's talk about seats

"BaconSandwich is tasty." (baconsandwich) 02/27/2020 at 23:15 • Filed to: Design Details, design, seats

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There’s a few questions on my mind that have been bothering me for a little while. They’re about seats.

I have a very rough understanding of how car seats are made. There’s some sort of stamped metal frame, with a few metal springs hooked over it, and then a bunch of polyurethane foam (or something similar). All that gets wrapped up in a nicely stitched covering.

Supposing a person wanted to make their own custom car seats, how difficult would it be? Would it be legal? Would it be safe? Would it turn out half-decent, or, in typical Top Gear fashion - “ambitious, but rubbish”? After seeing the concept interior for the Porsche Taycan (back when it was called the Mission-E), I really kind of thought they were interesting seats. Supposing a person wanted to make something similar, would it be possible? Is it possible to buy polyurethane foam kits, and cast the foam yourself? Does a seat like that even have a metal frame? (I imagine for the concept car, the requirement is “make it look good”, not “make it work, then make it look good”. So who knows - does it even have a metal frame in the back, or is it plastic/carbon fiber?)

Here’s another set of interesting seats - this time from the Audi AI Trail concept. Those side bolsters make it look pretty difficult to climb in/out, but they seem to have a similar look in my mind.

The closest I can think of off the top of my head would be the BMW i3 seats, which I still think look pretty good:

A little more traditional compared to the other concept seats, but at least these ones meet safety criteria and are actually attainable.

Now the other big question about seats that has been bothering me. How does the seat reclining mechanism work? It’s not like I recline my seat very often, but from what I remember (at least in the Civic), there doesn’t seem to be set detente positions. You can set it back at whatever angle you want. If that’s the case, how does the seat back remain rigid in an accident? What manner of mechanical witchcraft allows it to be positioned at an arbitrary angle, and when set, not move? Or am I just not reclining my seat often enough to notice that there are actually set positions every few degrees? If there were set positions, I could imagine some sort of notched metal piece that allows a pawl to snap into position, locking it at that spot.

And to think these are the sort of questions that keep me up at night...

wafflesnfalafel > BaconSandwich is tasty. 02/28/2020 at 00:38

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I really liked those highly bolstered, open, cloth seats in the older Honda Preludes - those were super cool and very functional.

SmugAardvark > BaconSandwich is tasty. 02/28/2020 at 01:00

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Best advice I can give you, go to a local junkyard and buy a cheap seat out of something. Disassemble and tear that bad boy apart. Once you’re done, try and reassemble all the mechanical bits. If you can stitch (I, for one, am atrocious at it), try and put the outside material back together as well as you can .

I’d personally recommend doing it with an older seat without any electronic bits, at least for the first time.

As for reclining mechanisms, I don’t know that all seats are the same. But here’s a great video that explains one that I’m familiar with:

just-a-scratch > BaconSandwich is tasty. 02/28/2020 at 01:08

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I have all the confidence in the world that if I made a seat, the first ten attempts would be garbage.

Also, in my experience manually adjusted seats have finite locking positions for reclining. I can imagine that a lot of powered seats have wo drives or other mechanisms that would not require a secondary locking function to stay in place.

Most OEM seats are frame seats that offer good passing and adjustability.

The other major category is the frame seat. Those use a thinner corrected seat back to provide rigidity. They’re often lighter and thinner than frame construction.

I hope that's useful and not too remedial/basic.

SilentButNotReallyDeadly...killed by G/O Media > BaconSandwich is tasty. 02/28/2020 at 05:24

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I welded up the recliner mechanism of the driver’s seat in my Lada Niva back in the day...this was no mean feat as it was still in the car....and stuffed full of coconut fibre and encapsulated in Soviet era vinyl.

Other than that...I'm not skilled enough to comment.

Minardi Gras > BaconSandwich is tasty. 02/28/2020 at 09:55

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The Elise Club Racer was sold with some very concepty seats that presumably met all the relevant safety criteria. No recline here though.

BaconSandwich is tasty. > SmugAardvark 02/28/2020 at 19:06

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This video was actually quite helpful.  It definitely makes more sense now.

BaconSandwich is tasty. > Minardi Gras 02/28/2020 at 19:07

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Interesting.  They seem like a hard shell made from (something?) with some padding.  Pretty neat looking though.