T8erbug's GSF600 Bandit

[Guest]

I haven't been posting much on my other thread for a while and it's because I picked up a commissioned project. It's a 600 Bandit that I believe is a second generation. The frame was a challenge and not nearly as good looking and workable as the first gen. But I took on the challenge to pretty it up a bit. It's just about done now, so this thread (as opposed to my other one) won't take 5 years to finish

Also, I used photo$ucket (the dollar sign is an 'f' now in my mind) before, so now all of my old threads are junk. I'm going to just insert the images for now and see how that works.. Suggestions on image posting are welcome!

IMG_1849.jpg

This is how she looked in the classified add when we bought her.

[T8erbug]

Stock Form




Unfortunately, by this point I'd already taken the tail body work off. These pics were more for my personal use so I could plan/map out what I was going to do with the rear end of this bike.


Without the seat



The hideous frame/tail section of this bike.. All those tubes at such weird angles... and that pinched 1.5" tube meeting up with 1" tube. Gorgeous

[T8erbug]

Cutting Away

[T8erbug]

New Subframe


Started laying out the bends








The main hoop was the toughest part. I'm not sure if you can tell, but there are 5 bends on that sucker. This was my first real project with my bender so there was definitely a little learning curve. My bender is awesome! The only downside to it is the bend offset is right around 4-5" so getting bends in tight spots and close together really takes some planning. You've got to know which bends to make first to make the other ones possible. It also helps to do the mirror of one bend right after the other side if you can. I tried to do them all in series on the first attempt and ended up with an asymmetrical hoop.




I forgot to mention I found a guy selling a Bandit 1200 locally without the engine. I was able to get a killer deal on the whole rolling chassis. Unfortunately he had cut the frame to get the old engine out quickly. It worked out for me though because I was able to pick the bike up in two halves and stick it in the truck of my little car haha

[T8erbug]

Also, the CAD program I used to design this subframe is totally free and very usable for anyone with any kind of 3d CAD experience. If you don't have experience, this is a great program to learn on. It is called Fusion 360. It's got full CAD capability and they just added a sheet metal module. It also has a true 3d CAM package that is incredible! If you do any kind of design, sheetmetal, plasma cutting, machining, then this program is a must see. (they're certainly not paying me to say this stuff) I'm a huge advocate of what they're doing right now because of how supportive they are of the DIY community. I don't think it will be free forever, but it's certainly worth using while it is. It's made by Autodesk (the same folks who made the legendary AutoCad). What's strange about the whole deal is that Autodesk already makes a full-featured 3d CAD program called Inventor.. and it's horrible.. and people actually pay for it. Autodesk's Fusion 360 is (for most folks) every bit as good as Inventor and in many cases far better. So, if you've always wanted to get your hands on some CAD software like Solidworks or (insert dream CAD here) then you seriously need to give it a look. Did I mention it's cloud based? In other words, you can totally run the program on a laptop or other less powerful computer without bogging it down. Anyways, check it out. Cool stuff. And it's how I designed 95% of this bike.

[T8erbug]

Subframe Tabbing and Setup



Me and my buddy Ben made these sweet little seatpan supports that accepted the factory seatpan rubber bumps. This project features a bit of recycling of factory parts and pieces throughout. I think it will help keep the overall feel of the bike as a factory bike. Custom bikes are cool and all, but it often seems the builders overlook the little things that make a bike feel well-built. Using zip ties and hose clamps are things I am trying to steer clear of haha. By using some of the Suzuki parts I cheated in making the bike seem like more of a factory build (which is weirdly what I want). I guess ultimately I just want the bike to look and, more importantly, feel like a well-built machine.

[T8erbug]

Seatpan Making

This was overall a decent yet horrifying experience. First time I've ever worked with fiberglass. While it was a little overwhelming at first, by the third or fourth layer, I was more dialed in on what I was doing. Getting the catalyst:resin ratio just right for the ambient temps and working time was one of the bigger challenges. Also, viscosity was a pretty big challenge. Having the resin mixture too thick makes rolling out the bubbles much more difficult. It also makes having uniform thickness and saturation of the resin next to impossible. By mixing your resin and catalyst first, then adding acetone to the mixture, you can achieve a more manageable viscosity. I'd compare the unthinned viscosity to maple syrup or slightly thicker while the thinned version is closer to water. Be careful how much acetone you add. I've read that if 10% or more of your mixture is acetone you will have curing problems.

Building the plug was also tedious and labor intensive. There are a BUNCH of things I'd do differently if I had to do it over again. Here's what I'd do if I were to build the plug over again to minimize work, cut hours of labor from the process, and have a higher quality plug (which results in a higher quality part):

At first I thought my mistake was using the pink builder's foam.
The pros of using the foam are:

• easy/quick to shape
• cheap
• availability

The cons:

• cannot be used as a plug until a hard, smooth, sandable finish has been applied
• melts when paints or chemicals are applied
• lots of debris while working with it

When I first finished the seatpan plug I thought it was a huge mistake to have used the pink foam. While it helped me quickly get the shape I envisioned, I couldn't just prime it and sand it. So, I used body filler to achieve a hard surface layer. It has worked for past projects just to achieve a shape but I realize now my mistake was not in using the pink foam as a building material, it was completely in using body filler as a surface layer. The body filler heats up as it hardens and while it's hot it can slightly melt away the foam underneath it. So, you have to add more body filler to fix things that become misshapen. By the end of it all you change the shape so much by adding the body filler you end spending more time sanding and reshaping than you did to get the original shape from the pink foam.

Conclusion 1:

If you're going to use pink foam to shape any sort of body panel and use it for a plug, there is a better method for attaining a hard, workable, surface layer.

https://www.youtube.com/watch?v=MAinuf5I_dw

This video series is excellent for demonstrating what I should've done. The polyester resin will not eat away at the foam. Therefore, you can use the pink foam to quickly rough out a shape, then add resin and drape a thin layer of fiberglass over the plug. This gives you a good hard surface to sand, prime, and wetsand. Then you can lay your part up on the plug and get a good clean release.

Conclusion 2:

Just machine the plug out of MDF, give it a quick hand-sand with 300ish grit paper, and prime it. I realize not everyone has the machines/tools to make this one work, so the pink foam method with thin glass layer is a great alternative.

Here are some pics of the shiz-show:






After prime and wetsand

[T8erbug]

Seatpan

I didn't mention gelcoat. I had some aligatoring in the gelcoat. It bummed me out a little, but overall it turned out really well and bonded to the fiberglass perfectly. In this situation, you'll want to purchase unwaxed gelcoat. It will only cure fully in the absence of air. This is how it bonds so well to the glass. Once it is surrounded by the plug on one side and glass on the other, it will start to fully cure. If you're adding gelcoat afterwards, you'll want a version with wax. The wax will rise to the air-side of the gelcoat and help it fully cure.


Applied gelcoat


First layer of glass was mat to get into all the corners and etc.


Next layer I used cloth. I then alternated between the two and finished with cloth.

[T8erbug]

Seatpan Continued










Note the studs were glassed over from the back

[T8erbug]

Final Touches

I got in touch with an upholsterer that will do the seat for me. He asked that I lay out a pattern for him, so I quickly roughed one out with sharpie on the seatpan foam (which is camping mat by the way! Only cost about $6 a mat). I also mocked up the headlight and got the wiring figured out. Not pictured is the new speedo, which I've almost got fully wired up. I'll explain that in a later post.

[hannibal]

Wow, I'm amazed by your skills!

[Buffalo Bill]

All very neatly done with great attention to detail! Nice reduction of metal mass on the sub frame.
Very useful info about molding fiberglass shapes.

[LarsKroghStea]

Nice work!

[nvr2old]

Really nice work. That's some major surgery that you've done to the sub-frame..could lead to a disaster, but you did a great job on that and especially the seat pan, too. Hard to believe it's the same bike. Can't wait to see further progress.

[LarsKroghStea]

Nice work!