DIY Bobber Motorcycle Seat


DIY Bobber Motorcycle Seat

Project: 1984 GL1200 Bobber Custom by Kartch Customs

Today I wrap up the seat on the GL1200  build with a run down on how pretty much anybody can build their own custom designed butt bucket.

So you built a custom motorcycle and need to top it off with a custom seat. Or, you already have a tricked out ride but just want something to make it your own. There’s nothing like making your own seat to say, “I’m pretty much the king of the world of motorcycles”. OK, that may be a little extreme, but fabricating your own seat is still pretty awesome.

This is a seat I knocked out for a recent motorcycle build where I took a stock 1984 Goldwing GL1200 and changed it from an old man’s touring bike to a custom one off custom cruiser. You can check out more of the details at Kartch Customs.

In keeping with the, “build it instead of buying it” theme of this build, I grabbed some sheet metal and drew out a seat pan shape that I liked and seemed to fit the bike. I used a grinder to cut the shape out and smooth out the rough edges. Using a mallet I pounded the metal over a 2″ section of pipe to give it the shape I wanted.

I am a big believer that the shape of your seat pan has the biggest impact over seat comfort. Even more so than the NASA approved foam you bought to impart buttock bliss to your seat. I try to curve the sides, the front, and rear of the pan to fit my skinny butt in the best way possible. If you can find a size and shaped pan that is comfortable in raw metal, it will be that much better when covered in foam and leather.

If you don’t have access to a welder or grinder you can always pick up an aftermarket pan from just about any custom motorcycle supply shop. A sweet pan can also be made out of fiberglass using some fairly simple skills one can learn from a few YouTube videos. Personally I would rather be burned by some hot metal than deal with the fiberglass itch.

From there I cut up some 1930 something Chevy springs and made up a suspension style seat. I had to fabricate some mounting brackets using some scrap metal, bolts, and some nuts. Since I was completely fabricating a completely new seat design and not using any of the OEM mounts or anything, my seat system was a little more complicated. You may be using stock mounts or even the stock pan which would simplify things a bit.

Once the pan and mounting system is in place the next step is to cover that thing with your choice of padding and covering material. I went super high tech and used some carpet padding I found in a dumpster for the foam and some leather from Tandy Leather. For the adhesive needs of this project I used contact cement for sticking things together.

The first step was to remove the pan and glue on some foam. You can see in the picture that I powder coated the seat pan. I live in Arizona and the reality is I could have shot it with some cheapo spray paint and the seat would still be around for cockroaches to chill on after we are all long gone. We just don’t get that much rust in these parts.

Some people get all crazy and use electric knives and such to remove the excess foam. I get good results from a razor blade. Use what you got. The foam doesn’t have to be perfectly cut. You just want it close to your final shape once covered.

Grab your chunk of leather and plop it down on the floor. Set your foam covered pan top down and trace around the leather leaving two to three inches extra all the way around. You need to be sure you will have enough to stretch over the foam covered pan while still leaving some extra around the edges. You will need to cut a section of leather that will fit over the top of the seat and a section that will fit over the top.

You will need to make cutouts for your lower section of leather to clear whatever mounting brackets you have.

I used some sandpaper to roughen up the surface of the lower pan to give the contact something to grab on to. I then coated the leather and the lower portion of the seat pan with contact cement. I use multiple layers of cement letting each layer dry between coats.

This is a shot of the lower leather panel glued into place.

Now you want to take the top leather panel and wet it down with some hot water to soften it up and then start to stretch the soft leather over the foam. I don’t usually use any glue at this point because I want to make sure I have the best fit possible before permanently attaching the two halves of leather together. I just use my palms to push and stretch the leather over the form. The leather is pretty soft at this point so you have to be careful not to scratch or dent it. It doesn’t take much time before the leather is molded into a good shape over the foamed pan.

I use some paint sticks top and bottom and C-clamps to hold things into place while the leather dries. I you need to add more hot water and make work things out a bit more, this is a good time to do it.

Once the leather has dried, go back and start laying down multiple layers of contact cement and then carefully put it all back together. Use a mallet and smooth faced hammer to carefully pound the mating surfaces together. At this point wet all the surfaces and carefully work around the shape of the pan to mate the leather in the best possible shape. A body hammer works really good for this step.

The next step is to trim and stitch the leather halves together. There are some great tutorials on YouTube on different stitch types and how to do them. This is one step that I prefer to farm out. I take what you see above to a local cobbler and have them trim up the excess leather and run the rest through their commercial sewing machine. Someday I will stitch my own when I have a little extra motivation. Someday I may sprout an extra arm.

Use whatever your favorite leather conditioner is. Some swear by Neatsfoot Oil and others use Olive Oil. Once the leather has been reconditioned post installation abuse I use a colored shoe polish to make is look more interesting. The more artsy among yourselves can carve designs into the leather or whatever else to “make it your own”. I tend to keep things fairly simple and straightforward.

There you have it! With a little patience anyone can design and fabricate their own motorcycle seat. This is just a primer of what is possible. The main thing is to have fun!  If you have designed your own seat, shoot me an email and I’d be glad to showcase what you have done here on Kartch Customs.  Hasta!