How to make a custom seat.

[EXBEN]

I've been getting a few people asking about making a custom seat so because I needed to make on for the TL, I thought I'd through up a bit of a how to. Before I start just know the usuall disclaimer applies ( If you fuck up don't blame me).

There's many way's of making a custom seat for your bike, eg: a piece of neoprene glued onto the bodywork, a piece of checker plate screwed on etc... but when it comes to a bike your actually going to ride then a decent seat is the go. This is how I go about it.
Here is the seat unit Im using on the TL Im building at the moment, as you can see it has a full glassed in seat area which makes life easy for me, but if your bike has a cut out area you'll need to fill it in with cardboard & masking tape so you've got a reasonably even area to work with.

http://www.streetfighters.com.au/forum/upload/77964657654898.jpg

[EXBEN]

First I rub 3 good coats of release wax over the area I want the seat to go, the stuff I use comes from my local fiberglass supplier.
I like to make my seat bases out of fiberglass because you know it's gonna fit exactly over your seat unit.
I usually use 4-6 layers of 450gsm chopped strand matt depending on the type of shape required.
http://www.streetfighters.com.au/forum/upload/779646576150402.jpg

and then???

[suxukifreak]

You grab a beer......

[EXBEN]

Once the wax is dry you can start laying the glass down ( Im assuming you know how to use fiberglass ) for this seat I used 5 layers. After the first three were down I put some 6mm Tee nuts in the positions I wanted so that the seat base can be screwed to the seat unit easily, then the last two layers went down. I use Tee nuts cause they have some nice barbs to bite into the glass so they don't spin( You could also just use some squares of aluminium, about 4-6mm thick, which you could drill & tap ). The masking tape you see is there to support the glass so I can extend the front of the seat out a bit so it matches the tank nice.
http://www.streetfighters.com.au/forum/upload/77964657697243.jpg

Once the glass was cured I seperated it from the seat unit, turned it over & marked out the shape of the base I wanted.
You'll also notice I've drilled through the Tee nuts with a 5mm drill. Do this before you remove it from the seat unit so you get it in the right spot.
Then I run a 6mm tap through to clean out the threads.

[EXBEN]

Using my trusty angle grinder with a 1mm disk I trimmed out the shape then cleaned it up with a flap disk then sandpaper.
So now you've got a seat base.
Next up you need some foam, I get it from my local motor trimmer, the pink stuff is the go cause it's firm without being too hard & it gives good support.
Also get some 3mm foam, you'll see why in a minute.
http://www.streetfighters.com.au/forum/upload/779646576116222.jpg

I used 50mm foam cause you cut a fair bit of it away. You can see I've shaped it to match the seat base, this is so the foam doesn't want to spring off the base while your working it. I use a bandsaw to cut the foam but an angle grinder with a flap wheel works as well.
Next you need to glue it to the base, preferably use a good quality foam adhesive, I use the 3m stuff cause it works great & you don't get a hard edge on any joins.You can get it from somewhere like clark rubber.

[EXBEN]

Next comes the creative bit. You gotta decide what you want your seat to look like, personally I think you can't go past a traditional saddle shape for comfort.
Here I've rough trimmed the shape on the bandsaw then I use my air grinders with flat sanding disks to trim the shapes. You can also use you grinder with a flap disk but be carefull cause these can be quite aggressive. Take your time here cause your trying to get it as smooth as possible. Another tip for final finishing is to use an orbital sander, but you'd only use it to get the final few slight bumps out cause it's pretty slow.

http://www.streetfighters.com.au/forum/upload/779646576105166.jpg

You can see where I've added a bit of foam to the front of the seat cause I wanted it to go up in the front a bit more. This is where it pays to use foam adhesive that dries soft so you don't get a hard line in the middle of your seat( Believe me you'll feel it & it'll piss you off.)
Once your happy with the shape & finish glue a layer of the 3mm foam over the whole thing. This smooth's out any slight imperfections in the foam so your covering looks nice & flat.
Im using black Macrosuede as the covering.

[EXBEN]

Once again the spray adhesive comes out, be sure to coat both halves leave it for 15 seconds ( for this brand) then lay the covering on being carefull not to get any glue on the good side & be sure to get the position right cause this stuff sticks like a bastard instantly.
Work it from the middle out then flip the seat over & spray a bit more glue on the underside edge, & start wraping it over.
You'll need to cut a slit where the fabric gathers on the underside & you may need to remove some excess material. Stick it all down & give the underside a final trim. Depending on the material you use you may need to staple the fabric on as well.

http://www.streetfighters.com.au/forum/upload/77964657667749.jpg

So basicly thats it, all you need to do is screw it to the seat unit & your done.
All proper like ;)

[chopiesel]

good work thanks for that ben, i am making one for the tiller and wasn't sure if i should use glass or sheet metal for the base. you have solved that problem!

[Jockney Rebel]

you should do a how to book ......

[Iceman]

Top work Ben, I'll be needing to make a seat soon, so you couldn't have had better timing.

[Gix11]

Me too, and off course that goes "straight to the Pool Room" .......I mean "HOW TO" section of the website.

[fimpBIKES]

thanks ben

once again top work!

my gemo seat-unit actually came with a little fibreglass seat shaped bit so i guess most of the hardwork is done for me :)

[dane_ra]

Anyone who got to the fools run will know my bike desperatly need a new seat, cheers Ben

My bike also needs a lot of other new stuff, but thats off topic[:p]

[shift1313]

great how to there ben, is there an actual name for the foam you used? did you use random weave for its strength? i use random weave for molds and weave for final parts, for weight reasons. Just curious. I really like how you molded the seat foam to it as well, great job. Is the spray adhesive all thats holding your seat cover on? I tried to staple mine on(vinyl) with no luck, i might give this a shot. I also like the T nut idea. I stuck bolts in mine so the bolts go down through the tail but its not the greatest way.

[EXBEN]

Matt, Yeah I find chopped strand better for rigidity cause you don't want the base to bow up at the edges when you stretch the fabric on.
Woven also works fine, it's just personal preferance really.
If weight was going to be an issue I would make a carbon fiber one.
Because I covered the seat with macrosuede I could get away with only using glue,Vinyl always needs to be stapled on because it's quite rigid. I always use an air stapler cause they have more grunt than a hand powered staple gun. What were you using?
There's many way's of fixing the seat down & using bolts is quite acceptable, T nuts is just the way I like to do it.

[Gix11]

Just as an addition to this topic, this crossed my path this morning. Maybe old, maybe new, who knows?: http://www.diymotorcycleseat.com/

[DiscoDan]

that guy needs to get out more, it's a seat for fucks sake

[HueyonaBlade]

quote:Originally posted by Gix11

Just as an addition to this topic, this crossed my path this morning. Maybe old, maybe new, who knows?: http://www.diymotorcycleseat.com/

Your a Gem Si I have been freaking looking every where for this is this a sticky[?]

[Gix11]

No, but it can be...



....and look at that! Now it is!

[HueyonaBlade]

quote:Originally posted by Gix11

No, but it can be...



....and look at that! Now it is!


Cheers mate I know in the long term I will appreciate not have to delve so far into the archives;)

[Gix11]

Hey dave, are you on about the link to the seat website or Ben's topic? If it's Ben's topic you know it's got it's own page in the "HOW TO" section don't you?: http://www.streetfighters.com.au/ASF_howto.asp