Urethane seatfoam carving, etc....

Today I spent the morning cleaning up any irregularities in my seat pan, evening up the exposed amount of frame rail, sanding sharp edges, etc. Then I set about the business of carving my set. The cushion I rode yesterday and the day before is going to be the correct firmness, so here goes.

In the first four pics, notice the line down the center, and the arrows. The arrows are to exactly define the point of dead center in the uncut cushion. The line connects the arrows. There were other lines I used to ensure symetry, but they have been sanded out. Mark it up as necessary to keep yourself even on both sides. Symetry affects both the looks and the performance of the seat cushion...your back will tell you how if you get it crooked. I use kind of a grid to keep track of where I want material removed so I so it the same on bothe sides.

Here's the rough cut foam, from the turkey knife. I did this on the bike, using the lines and the frame to guide the rough cut.
Leave some for sanding...
Here's the sanded cushion, sanded to shape with 40 grit on a rubber sanding block...

and from the side...

That's the basic platform. I need to load som more into photobucket..be right back.

Here you see how the foam doesn't fit on the pan. This is because the pan is formed to everything on the bike that was under it whan the fiberglass was layed...

So I used the turkey knife to mark and cut out relief areas to match up with the pan so the foam is a form fit on the bottom...

That puts it down on the pan, and the vinyl pulls it the rest of the way down...just a little bit...

Here's the first stage of making the bum stop. Foam is cut to thickness required (leave some for sanding) and glued on with spray adhesive. It's just like one piece of foam, now.

Next the foam is cut with the turkey knife and sanded down...


Then I made a four piece cover for test riding and keeping on for a few days while I'm sick of doing the project ...:sick:

On the bike it rides low, gets me out of the wind, doesn't cause the buffeting I asked about yesterday, and feels the same at 90 as it does at 60! Turn in is quick, and foot initiated turning is much more effective...a hard push down on the outside peg and in you go...very nice.

I will make some small cosmetic changes to the front of the foam, after I ride in this good weather for a few more days. The bike looks great..yeah the seat looks handmade, but that will change soon. For now I'm very happy to be back on the road and be on the home stretch...just taking a project break because I really get grouch if I don't ride. Ive ridden well over 200 test miles in the last 36 hours, so I'm not grouchy now

ronboskz650sr wrote

Turn in is quick, and foot initiated turning is much more effective...a hard push down on the outside peg and in you go...very nice.

Huh? I've never heard of this before. Or if I have I've forgotten it. Foot initiated turning. If I could get a little more detail on this I'd appreciate it.

It never worked very well with this bike before. I believe the push on the opposite peg actually causes a slight, involuntary push on the opposite bar, but some of the sportbike magazines don't say that. Basically, you just stand on the outside peg, just short of coming off the seat. I've only been able to get it to work a little bit. Never tried it hands off, guerss I should. When I do it now, the bike begins a turn to the opposite side immediately, and many of the curves around here suddenly became total no-brainers. Even some that used to need significant pressure on the bar, just don't anymore. I think it's the 2-3 inches lower seat height. I weigh almost 220 in gear, and that's a pretty big chunk of weight to move that much lower in the cg. Plus the bike is now a full 20 pound lighter than stock...aftermarket exhaust, center stand removed drag bars, and a new seat without fender. Alot of steel is gone from this bike, and the front fender is next to get chopped. Probably not going the fiberglass route on it due to fork bracing. All that adds up and my bike has changed character totally! I love it!

Less weight sitting still = Less weight to throw in and out of corners.....Wow, physics applied to real life stuff! You said sumthing about upholsterer??? He gonna take "guidance" from you re: what yer looking for? Looks cool, by the way......

Thanks, Pat! The upholsterer knows my concept thoroughly, and helped me come up with the type of seat cover i want, for this look. He will attach the cover to the upright portion of the tailpiece (stuffing the vinyl into a metal band behind the cushion) , so the cushion is nearly flush (as close as possible) with the top of the glass piece. His ability to do that really depends on my final sizing of the foam. He told me what he needs that way to make my idea work. Great guy, BTW...and very busy!

Today a biker at church asked me why I was going to use an upholsterer..."I thought that looked pretty good" was his description of my test seat while we were eating lunch. He did look at it up close, too. Actually I think the paint is so good it draws the eye away from the vinyl...it is really glossy.

So...I have enough vinyl left from my $6 Walmart bolt to make one more, maybe two. I can whip one out in about an hour and a half, now that I understand how to make a 4 piece cover like this one. Yes, I'm going to try again. What is there to lose? Might just hit it on the head this time! I have to modify the seat/tank junction a little anyway, so here we go again! Not til the weather gets worse, though :laugh: :laugh: :laugh: .

Ron, you're wicked productive. You do nice work.

Thanks, Chet. I'm trying new things, and just loving it...but now I must ride. Last three days testing the seat has been so great, i'm waiting til bad weather to finish it up. I only took a week to paint the tank, due to some bad painting days after i got started, and it felt like a lifetime! I just love to ride. I need a rat bike, or some rainy days to finish up the seat cushion. Then, I need to finish up the paint, on the forward surface of the tail, and a small 1/8 inch touchup on some tank damage (stupidity at the pump). Overall, the bike is plenty rideable and very good-looking except on close inspection. That stuff will just have to wait now...I'm re-hooked on riding it! :laugh:

What density foam did you use for your seat? I'm about to build a lower/straighter seat for a KZ1000 and I'm not sure what to get. I have easy acess to any type on the market (I have immedeate family in the upholstery buisness)

I don't know, but the upholsterer thought it would be too firm. I sat on a sample on a wooden stool, then bought some, thinking I might need some softer stuff on top. Didn't need to do that after test riding the firm stuff...so, it's really firm, I just don't know that much abut it.