Custom seat questions, shaping foam & adhesive use?

[cggorman]

Been a long while since I posted here but I was hoping I could get some tips and/or opinions on my first custom seat project...

I've got the pan formed and I'm laying on foam now.

The pan is 1/4" aluminum
Foam is 1/4" neoprene. Probably 3 layers.
I'm using Barge contact cement to laminate the foam.
The cover is leather. "Black Motorcycle Side" from Tandy. 4-5oz weight. I believe it's chrome tanned. It's soft and somewhat stretchy.

I still have to make the cutting pattern but I'm planning to do it in three pieces. One for the top ane two bands around the sides. The joints will be butt stitched by hand with a cross stitch using Ritza 25 (Tiger) 1.0mm thread.

I'll include some pics below to help explain, but here are the couple questions I have...

1. Given three layers (5/8") of foam, would there be significant benefit is cutting out some reliefs for tailbone and sitting bones? Any real world experience riding on an ergonomic shaped seat would be helpful. I've only ever had "flat" seats. I'm thinking a bit of shape might be more comfortable, but I'm not sure.

2. Once the foam is done, is there any difference between cementing the leather to the foam or leaving it "dry"?


Thanks all!


The pan


Stitching trials



Ready to shape foam...maybe? how/where? The silver lines are sorta where the highest pressure areas are with me on it. Was thinking of dishing those areas by 1/4" - 3/8"...


Cement leather to the foam?

[rockman96]

1. Given three layers (5/8") of foam, would there be significant benefit is cutting out some reliefs for tailbone and sitting bones? Any real world experience riding on an ergonomic shaped seat would be helpful. I've only ever had "flat" seats. I'm thinking a bit of shape might be more comfortable, but I'm not sure

Not an expert by any means, and I took my foamed pan to a custom upholstery shop to be covered, so can’t speak for that aspect.

I did fab and foam my pan though... I’m thinking you will eventually redo what you have for padding. Instead of cutting down areas, I would suggest building up the surrounding areas. From experience, 1-7/8” of foam gets to feeling pretty thin when you’re putting down miles.

In case you’re interested, I made my pan by laying rags in and across frame strategically for clearance, wrapped with 5 or 6 layers of suran wrap, and laid down fiberglass. The pan is form fit, and almost snaps into place.

[TriNortchopz]

Looks like you have a good start on your seat. Here is a thread about building a seat which may have a few useful tips or ideas for ya:

From: Choppers Australia, The Chopper Shed

Padding Steff's seat...

...I've not found anything as comfortable and long lived as 'consolidated' foam... made in various wieghts. I buy it in 2" and 1" slabs. Consolidated foam is far superior to high density foam...Padding is made up of a number of separate pieces glued together and to the seat and then shaped with a knife and finsihed with an angle grinder...I use Selleys' Quikgrip(Kwik Grip) contact adhesive. It is very strong once set...You don't want any pressure points. Rider's seat base has also been trimmed at the front with a knife to prevent pressure on the rider's inner thigh muscles...Now out with the angle grinder to smoothly contour the seat...To finish the seat, I glue on a thin layer of softer foam. This makes for a nice smooth finish and also gives a nice soft layer...Don't run a bead around the edge unless you like cutting off the circulation in you legs!... Don't use buttons, they create hard spots that become very annoying on a longer trip. Under your seat cover run a layer of plastic to prevent water getting in at the stitching and and soaking the foam...When making your own seat, put a temporary cover (panty hose work great!) on the foam and ride the bike for a week in case you need to remove a bit of foam...If you want to do lots of riding... take care at this stage to make your seat comfortable as you can within your overall design.
See more,including the full seat build here:

http://www.choppersaustralia.com/forum/viewtopic.php?f=60&t=7128

and some FOAM BASICS:
The goal here is to provide a simple, very basic understanding of some key characteristics of foam so that you can make your seat more comfortable. That's pretty much it...
Firmer Foams Used Primarily As A Base Layer

Softer Foam Primarily Used As Top Layer

http://diymotorcycleseat.com/foam-types/

[Tattooo]

Very nice start...

[Dougtheinternetannoyance123]

Not an expert sexspurt either but heres my take based on my experiences,,,,, in some I take to one of several local shops when I need something complicated or nice details I cant do.

I have reupholstered a ton of stock British Bike seats myself and pretty good at it IMHO, And can tutor on that, But customs it seems its ALL about the foam, Many use 2 different types sandwiched as each type has unique properties, I personally would NEVER glue the upholstery to the foam, you need it to be able to slide and move a little. As to gluing to the base, Some do and some dont, In all the seats I have seen there is no rules, but most stock seats dont glue the foam to the seat pan. I have used a 3-m spray adhesive in some cases though......

Foam when it ages gets powdery and on vintage seats even though they look great, if you sit on them or even touch them the seat dandruffs powdery stuff all over. Foam has climbed in cost a HUGE amount in the last 10 years. I used to order a new seat cover for a vintage triumph and SOMETIMES order the foam too, recondition the base, etc etc, But now even at dealer cost Its cheaper to just replace the whole seat if availible. (Not related to a custom I know, but just speaking to my experience)

I have about 5 corbin seats currently, and on the gunfighter style on my sportsters I have one I LOVE,, very thin foam, and just cups my ass perfect, I can ride all day,. I have another on the wifes sporty and it hurts me in a certain spot on long rides but is comfy as hell for her. I HAD another one for a while and sold it. Same style gunfighter but was called a "Sundowner" and had a little backrest that fit thru a hole in the middle of the seat. I *THOUGHT* it would be good for some trips. You can pull the backrest out, or pop it in. The backrest was too far fwd, pushed my nuts onto the tank, and it was VERY uncomfortable for even short rides. So point is, even from the same company and seat to seat it can vary.

I used to do dealership work too,, and some of the customers were long distance touring types, We sold and installed a number of these ugly ass seats, But DAMN were they ever comfortable. People loved those things. You can buy off the shelf or take measurements and send in for a custom made for you. I bet you can learn some stuff on HOW they make such a comfortable seat,, (We had some on the shelf, but most are custom made)

See: https://day-long.com/

" COMFORT… AS WE DEFINE IT!

The Day-Long Touring Saddle is a saddle shaped seat specifically designed for driver and passenger comfort, incorporating our patented Support Suspension System. Each motorcycle seat is individually made to be the perfect seat between person and machine, according to your personal physical requirements."

-------------------------------------------
PS> Check out their "Foaminator"
See: https://day-long.com/foaminator/

hat Was Then…
For years Russell Cycle Products has depended on outsourcing our foam saddles that we incorporate our Support Suspension System into.

With no control over the finished product we were at times sent useless saddles that were to hard , to soft, or inconsistent in density.

This led to many problems when it came time to balance foam density with suspension system tension.

The marriage of foam and suspension system is complex to achieve the Day-Long comfort we are famous for.

The Foaminator | Russell Cycle Products
This Is Now…
In April 2008 Russell Cycle Products purchased our own Foam processing machine shown in the picture. We named it “The Foaminator”. The unit was custom built for us to meet the need to precisely pour the exact gram weight saddle for each individual Day-Long custom seat. By controlling the gram weight we can in turn control the multiple density’s required for total Day-Long comfort We can now calculate to a higher degree the proper gram density per customers weight factor. The processing has exceeded our expectations and we feel the comfort levels have greatly improved.

Here at Russell Cycle products we are constantly working to achieve the ultimate comfort levels. We believe this investment will move us one giant step forward in achieving that goal. As we always say “No two are alike”.

[cggorman]

Dammit! I'm not getting notifications of replies to my subscribed threads. I didn't realize this had some traffic. I forged ahead thinking it went under the radar.

Sorry.

Anyways, here is a photo progression up to today. I still have a little to do, but the important bits are done. I hope it holds up!

The raw pan was bent up by Pete at Rocket Bobs (many thanks!). I did the rivet holes and welding (160 amps isn't enough to 1/4" fillet welds, but I got it. Ugly, but strong. Hidden anyway.

The thinnest areas have about 1/2" of foam. The thickest are about 3/4". The batting is only about 1/8" uncompressed and just to hide some of my foam carving sins.