Making a custom seat (for a chopper)

[eichh]

I wanted to redesign my chopper which was going to require a rear fender chop and a new seat. The old seat sat directly on the frame and would vibrate your junk well beyond your comfort zone. So I needed to figure out how to keep it low profile because of my short legs but mounted on rubber to get rid of the vibrations. I have only done fiberglass once before but this worked out perfect. Ok to start I covered the battery and used masking tape to seal any gaps and taper odd joints That piece of wood is scrap I didn't use it.

Next I mixed up a tiny amount of the resin to see what I had tape wise that it wouldn't eat. As it turned out the transfer tape I use on decals worked great it stuck to the frame and was slippery enough the resin wouldn't stick to it (its clear in the picture). The 2 washers were placed where the rubber bushing will get mounted and the strip of aluminum is for support and something to screw the mounting hardware into.

Next was the glass work its self, I precut a bunch full pieces with relief slits in it and a bunch of random strips to fill and taper where it needed it. I forgot how many layers I did but it turned out about 3/8" thick. and the washers and support were cured into the resin so they were positioned perfect.

Here is the bottom side.

and top

Here it is cut out. Next I will mount the rubber bushings and mounting hardware.I used dry erase marker on the fender to figure out where to go.What I do need to know is what type of padding holds up nice ? I plan on upholstering it myself but I will update that progress in a few days.Maybe this will help someone out looking to do something similar.

[Duck-Stew]

Nice write-up, great work too!

Can't wait to see the final product... 

[Speeddog]

<bookmark>

[dbran1949]

Years ago I did some custom seat work very similar to this.  Down here in San Diego there was a place called UFO Upholstery Fabric Outlet

The thing I learned is to get the stiffest densest foam you can. What feels soft in the store is way to soft for sitting on. Get something that seems way too dense to be comfortable

[eichh]

I put these weird nut looking things on the inside of the seat and I will glass over them so they wont spin or pop out.

So then I made the bracket that will attach it to the fender.Drilled and countersank the screws so I can put the bracket on after the upholstery is on. These of course screw into the weird nut things.

Finally I polished the aluminum bracket that attaches it to the fender, glassed in the front tab that slips under the front bracket, sanded off the nasty chunky chow and gel coated it.


dbran, I hear yeah I need to swing by an upholstery shop and sit on a bunch of their stuff to see what feels right. I had some memory foam laying around but I just sank right through it. I am going to assume the hardest part will be riveting the vinyl or leather to the bottom.

[dbran1949]

If you are going to use pop rivets you might want glass in a thin metal strip around the edge on the inside (top) of the glass structure you just made. But you should rely primarily on contact cement

[eichh]

Here's the latest. The wife is the chemist at a carpet padding manufacturer so she brought home several differant density commercial grade padding squares.After a bunch of rearranging and sit tests I found a nice combo and layered them as shown. I had to wait till she left to get the turkey carver out ( in all fairness we have yet to carve a turkey with it) and that worked great to get the shape right.
Dbran would I use contact cement on the padding or just the bottom when I wrap around whatever it is im going to use.Or does anyone else know what steps to take from here. I plan on shopping for material tonight and attempting it tomorrow.

[Raux]

unless a woman is riding that, it looks like a ball buster with the center middle higher than the rest.

[TAftonomos]

I agree.  Get rid of that light tan foam in the middle/top, and blend the rest in.

[corey]

i say you cut a hole in it and fiberglass in a small dish for your balls to rest in.

[eichh]

The photo is slightly misleading. The top is Flat and about 10" wide where I sit on the brown section (the width of the frame). Its a long seat but I only use the back section.

[greenohawk69]

Other options to reduce or is that increase your chances of having kids in the future?   

1) Look at designing the seat more like a bicycle seat...space in the middle, as I have on my mountain bike.
2) Use Fox mountain bike seat shocks for a comfier seat.  Saw this on a cycle in HotBike magazine, June 2010, page 38.