DIY: Custom Seat shaping

[setasai]

Just wanted to put up a place holder. I just started my custom seat shaping for the rider's seat. Pulled off all the staples and put contact cement on both the seat and the foam of choice. I know some have recommended I use 3M's super 77 adhesive spray and stuff but I have contact cement lying around the house and so I'm using that. At least for the first layer.

Wish me luck, photos posted after I finish.

Update 2011-11-12: I must bow down to those that suggested super 77 adhesive spray instead of contact cement. Contact cement did not like the foam I was using for the seat and would not adhere at all. Switched to super77 and now it is setting. Tomorrow will begin the shaving process.

Update 2011-11-13: Ok here are some photos of the first revision of the shaped seat.
My goals:
1) remove the forward pitch as much as possible
2) raise the nose a bit to prevent sliding into the tank
3) add some support on the sides and a dip in the middle to cradle the butt
4) remove the hump in the middle contacting the tailbone
4) raise the overall height an inch or so

It wasnt as difficult to shape as I thought it would be. Since I didnt want to destroy the original seat foam, I slapped on a few layers on top and shaped each one as I went. I used an angle grinder with a masonry disc. I also strapped/bungee'd the seat down to a wide sawhorse so it wouldnt move while shaping.

The black lines are the locations I want to shave off. The shape is based off of what I see on the corbin seats. Today I've decided to give it a rest because my butt is numb to the changes after getting on and off it so many times.

Any ideas/help appreciated. Btw, this is another one of those ATGATT moments. Foam dust is NOT good!

[setasai]

Update 2011-11-14: Ok I've decided to scratch this whole thing because it just wasnt working the way I wanted it to. I'm considering switching to a different density foam and see what I can get out of it. So far no biggy, only spent $30 so far. $15 on foam sheets and $15 on 1 yard of marine grade vinyl.

[gfloyd2002]

Bad news. I was hoping your end product was uber comfortable, and got rid of stupid slope that jams one's nutz into the tank, a la a Corbin but at a fraction of the cost. And, in my fantasy world, after you recreated a Corbin for less than $100, I was going to pay you to do one for me.

[setasai]

Haha my thoughts exactly. Im still working on it. Its a little different from some of the other diy's online because those tend to be for non-sport bike shaped bikes. Seats for say a cruiser or a dual sport start out with an easier shape to get reshaped in my opinion. Even the profile of the pregen seats look easier.

We'll see though. Im still doing research on what is necessary to change the shape without shaving the original foam. Ill update this place holder when i make another change. It really comes down to how to carve and shape it. Buying foam isnt too big of an issue.

I've found 5 and 9 lb rebond foam but i still am afraid to carve into the original foam of the seat so instead i add more foam and carve that. So far i found, to no surprise, that gardening pads are too stiff. I may switch to carpet rebond foam next. Its only $30 for a massive sheet of 6x9ft.

Does anybody have some tips on the ergonomics of a good seat? Like add foam here and flatten this region but be careful on the slope of this part? That kind of thing?

[00NissanNinja]

I had pics of where I added foam in that DIY that is linked in the DIY Directory. Basically I built up foam in the places I circled and made the seat have a little less forward pitch. I shaved the original foam down though to have a flatter work piece to shape the foam on. Try seeing if you can find foam that is used in automobile seats. Its easy to work with.

[setasai]

Originally Posted by Phil7153

I saw this: http://www.kawiforums.com/ninja-250r...-seat-mod.html

He just cut down the stock foam, but im sure you could just slap on some two-part expanding foam and go to town on it. :shrug:

Yea I saw that. I guess my major grip with that is grinding down the original foam. If I mess that up I have no original to start off from. Give me some time to rethink this and who knows... maybe i'll get the guts to do it.

EDIT: I went outside to see how much is shaved and how I would go about it but came to the realization that the way he shaved it makes it impossible to use the very back end of the seat. Which I often use on freeway riding so I can tuck down real low. I have a pretty long torso and if I were to sit so close to the tank and tuck down, My helmet would be right above the bars. That wont work.

Originally Posted by 00NissanNinja

I had pics of where I added foam in that DIY that is linked in the DIY Directory. Basically I built up foam in the places I circled and made the seat have a little less forward pitch. I shaved the original foam down though to have a flatter work piece to shape the foam on. Try seeing if you can find foam that is used in automobile seats. Its easy to work with.

Those are exactly the locations I'd like to change. What density foam did you use? Were they more or less dense than the original foam.

I think my mistake was thinking I could use a denser foam on the top. I should probably use the same density foam as the original so forces are transfered better instead of creating more pressure points.

Automobile seats... hmmm yea that's not a bad idea. Maybe I can find a junk yard or something to purchase a few pieces of foam.

Thanks for all the ideas. I'll keep you all posted on how it turns out.

EDIT: looks like your method may work out better since it allows for the utilization of the entire seat. Still looks like I might need to shave the original foam though.

[00NissanNinja]

The top layer is denser than the layer I put under it. I think my top layer is just a tad less dense than that of the stock seat. So in my middle layer is where I did all of my shaping. I used less dense foam to help distribute weight in those areas, then wrapped the entire thing in one sheet of denser foam to increase support and make everything nice and uniform. I didn't shave the stock seat a whole ton but I did shave it down towards the back to give me more area to work with. Depending how you shave your added foam or if you aren't worried about height increases you may get away with not shaving it down to much.

[setasai]

What density do you think the stock seat foam is? More or less than 5lb?

EDIT: Has anybody tried using memory foam? I wonder how well this works.
http://www.sport-touring.net/forums/...html#msg556520

[00NissanNinja]

Don't quote me on it, but I think its less than 5 lb. Its not a large piece so It shouldn't be really dense. I think I tried some cheapo memory foam from bed bath and beyond and it just wasn't dense enough to make a real difference, but a better grade (i.e. not cheapo) of it might work better than what I found.

[cliff0529]

In that one write up you linked to, he was using a medical supply type foam. I'd try that first, it's designed for people in wheelchairs to keep them from getting bed sores (pressure ulcers, pressure wounds, etc). It might be a little more expensive, but it's designed to spread the weight and not completely collapse under your weight.

I've wanted to shave down my sportbike's seat and put a little medical grade gel padding in it and then put a really thin layer of foam over it to help smooth out the edges and see if that would help. But the gel pads are expensive and I haven't got around to messing with it. I think the brand I was looking at was Akton Polymer. A 18X18X5/8" sheet is $80! That would probably be enough to do 2 seats though. I'd shape the foam, then cut out a 5/8" deep recess to lay the gel insert in....

http://www.arthritissupplies.com/sit.../product/CAC53

[setasai]

Have you tried gel pads? I hear that if you dont have sufficient foam on top of the gel pads, they can actually made the seat feel worse because it caused pressure points.

[cliff0529]

Not really...We bought our touring bike in Cali and rode it home to Georgia. We borrowed an Airhawk cushion and a gel seat pad. Both my wife and myself preferred the gel pad (it was nothing more than a gel pad in a velour cover with a sticky bottom to hold it in place on the seat) and it extended our riding distances pretty well. Went from 100-110 miles before we were ready to stop to riding out entire tanks 180-190 miles before we were starting to get the "butt burn."

I have heard people say that it causes a weird sensation as the gel kind of moves around under you a bit and that it takes a while to get used too. However, the pressure points are caused by the foam and gel "bottoming" out. That Akton stuff is not supposed to bottom out and I've seen it used in many nursing and rehab facilities to keep pressure wounds to a minimum. Another drawback to gel is that it doesn't breathe and actually holds heat on hot days, which can cause monkey butt.

[setasai]

No perfect solution then I guess.

EDIT: I just found a store that sells only carpets. I asked about their rebond foam and they gave me some for free to try out. I think its 6lb but the only densities they had were 6lb or 8lb. If it works out well, I'll go back and get some 8lb memory foam rebond sheets and make another one. It would have cost $0.50 a sq ft for the 6lb and 8lb was $0.80 anyway.

[setasai]

I asked this upholstery shop to give me a quote on how much it would cost to reshape my seat and this is the reply.

Hi Brian this is fili from Abys the price to fix this seat is between $120 -$160 l would need you to come with your bike we will add foam and shape it as you need it until it gets comfortable the we re upholster it so it is a proses but we make sure that is done the way you spect it

Talk about unprofessional. Still though, $120+ is alot of money. I'm going to be getting an electric carving knife and another can of adhesive spray so that would bring the cost up to $60. I hope this ends up working.

[Jiggles]

Originally Posted by setasai

I asked this upholstery shop to give me a quote on how much it would cost to reshape my seat and this is the reply.



Talk about unprofessional. Still though, $120+ is alot of money. I'm going to be getting an electric carving knife and another can of adhesive spray so that would bring the cost up to $60. I hope this ends up working.

I'm pretty sure sweat shop workers speak better english. And they are so much cheaper

[setasai]

Ok here's an update on Rev2. I did some more researching and found somebody that did a similar seat reshape/mod on their versys.

Found HERE.

I thought it was a great idea and so I scrapped all other ideas I had about remaking the entire seat and decided to go small. Small is easy, small is safer, hence small is good.

The basic idea is to add some padding to the front and then shave down the back a little bit to flatten the bowed out portion. That is exactly what I did. I added some carpet 8lb foam in the front half of the seat, and then use an angle grinder with a 150grit sanding disc to flatten the back. The problem is that the rear middle is bowed upwards and that irritates my tailbone.

Some equipment I used that made the process easier:
$20 pneumatic stapler from harbor freight w/ T50 Arrow staples - look at photo below for exact length and model
I had a manual stapler but it just wasnt going through the plastic. This pneumatic stapler worked great.

Variable speed angle grinder is best but I didnt have one so I got variable speed controller instead. Then use a 150+ grit sanding disc so that the surface stays as smooth as possible and also so that you dont end up taking large chunks of foam off.

The outcome came out pretty good. It doesnt require too much effort and seems be in the right direction for more comfort. Pitch is lessened, height is increased a little, and the seat is flatter on the back so that there is less friction on the buttcheeks. Cradle isnt perfect and height isnt exactly where I would like it but I cant complain since it hasnt cost me much at all and I was still able to fit the original cover back on.

I'll probably make more adjustments but for now this isnt bad. Thanks for reading.

Oh and btw, had I not tried to mess around with all that other reshaping ideas, I probably would have only bought the stapler and staples. Which means, a more comfy seat for 2 hours and $30.