Monday, December 10, 2012

XS750 Restoration, Part 11 -- Sculpting in Foam

Despite my prep work last time, I am not ready to start building the fiberglass seat pan. I need to fabricate a steel hoop to tie the two halves of the rear of the frame together. Unfortunately, Lowe's had 1/2 inch diameter steel tube, and they had 3/4 inch solid round steel, but they did not have any 3/4 inch diameter steel tube. Consequently, I'll probably pay a visit to some of the airplane shops at Merrill Field some time this week to see if I can round up some 3/4 inch 4130 chrome-moly. How sweet would it be to build the whole frame from 4130? Unfortunately, that's just a bit (a lot...) beyond my skill level :) Consequently, I decided to get started on the side panels to cover the electronic/battery bay.

I started with a small sheet of foam that I purchased at Michael's, in the floral section. I cut it to roughly the same size as the opening that I wanted to cover.

Next, I marked the backside of the foam to match the inside of the tubing on the frame and cut the foam to fit between the tubes.

Cut, sand, fit, and repeat...

...until it fits. Well, at least when directly from the side. Unfortunately, the frame is not straight. It's curved at the top, and therefore, there is a gap between the foam and the frame. No problem -- one of the nice things about building fiberglass parts from foam molds is that if you screw up, or if a part doesn't quite fit, just glue a piece of foam to your work in progress, then cut and sand until it looks like you want it to. Unfortunately, the $10(!) Elmer's spray adhesive I bought...well, it sucks. Supposedly, it can take up to an hour to dry (grrr!), so we'll see if the left-hand panel is a single piece tomorrow, or if I need some different glue.

While the glue was drying on the left-hand panel's foam plug, I got started on the right-hand panel. There is one snag, however, that makes the right-hand panel a little more difficult than the left. If you look right in the middle of the triangle, you'll see a thick, black wire with a heavy rubber boot covering the end. If I am not mistaken, that's either the starter solenoid or the master battery contactor.

In either case, it sticks out far enough that the foam plug has to be carved out to clear the boot, so I marked the approximate size of the contactor, dug out a piece of 60-grit sandpaper and started recessing the foam.

Unfortunately, at this point, after test fitting the foam, I dropped the foam plug and broke off a corner. Okay, no problem -- as we've already mentioned, you can simply glue pieces back on if you make a mistake. The fiberglass needs to be smooth, presentable, and attractive, but the foam plugs can be a hodgepodge of glued together pieces, so long as you can sand them smooth before starting your lay-ups. However, as I mentioned up above, the spray adhesive I bought doesn't stick very well, or at least doesn't provide much initial tackiness. So, I glued the pieces back together and set them on my work table to dry.

To be continued...

Saturday, December 8, 2012

XS750 Restoration, Part 10 -- Commitment

Once again, it's been a while since I've written anything about the bike. That's due to a combination of factors: I've been waiting on parts, it's not terribly exciting to post "spent an hour stripping paint from the tank" ;) and it's been too cold outside (like 0F, +/- 5 degrees) for the last couple of weeks, so I haven't even been spending that much time working on the tank.

However, I have gotten a little work done since my last post. First, the stainless steel brake lines from SV Racing arrived. I think I could possibly have gotten Goodridge lines from Bike Bandit a little cheaper, but first, as I've said before, Blair is a great guy to work with so I like to support him and second, SV Racing's lines came with all of the banjo bolts I needed for the bike, which makes up quite a bit of the difference between his pricing and Bike Bandit's (although admittedly, not all). The finished brake lines look great, although I think I could have ordered the top line from the brake handle to the tee about an inch shorter. Still I'd rather have it an inch too long than have it an inch too short, so I'm happy.

After installing the brake lines, I hit a bit of a slump, unfortunately. Stripping the tank is no fun, and after a couple of weeks of nothing but grinding away at an unattractive, but quality, paint job, I was starting to get a bit demotivated. However, I had a little extra time the other night, so I grabbed the seat from the bike, and starting ripping the old upholstery off. Hmmm...I don't know. What do you think? A little naval jelly, and the seat pan should be as good as new, right? Yeah, I don't think so, either!

Fortunately, I was goofing off on YouTube the other day after work, and found a video of Herm from Dime City Cycles showing how to build a fiberglass seat for a cafe racer (and part 2). Dude makes it look SO easy :) so on the way home from work today, I stopped by Michael's and picked up a big flat sheet of foam, two packs of foam blocks and one can of Elmer's spray adhesive. Total cost: $31, although I think I'll need one more pack of foam blocks, and I still need the fiberglass and the polyester resin.

When I went out to the garage tonight to start laying out the new seat, however, I realized that my bike wasn't ready for me to start working on the seat yet. For a cafe racer seat, the rear frame of the bike needs to be perfectly flat, or at least, very nearly so. My bike, however, still had the rear fender (which sticks up above the frame), a storage compartment mounted on top of the frame, tabs for the seat hinge, and a bizarre, bulbous appendage on each side of the very back of the frame, to which a half-dozen bolts and the rear turn signals are attached. I started by removing the fender and storage compartment, then temporarily reinstalled the gas tank, so I would know where the seat pan needs to begin.'s starting to actually resemble a cafe racer, now!

But these things have GOT to go! do the stock seat pan hinges...

...and -- eventually -- the air box mount tabs (but not until I know I am happy with the K&N filters!).

Okay, well, there's the vision. Am I brave/stupid enough to dig out the angle grinder and start hacking away at the frame to make the vision a reality? What if I cut too deeply and damage the frame? What if I don't like the look of the finished seat and frame, and want to go back to stock? What if I end up selling the bike to someone else who wants to put it back to stock?

I read somewhere that fear prevents us from being successful, and I want this bike to be a success!

I took a deep breath, and...'s an action shot of yours truly removing the seat hinge tabs. While I was actually doing this, there were sparks flying everywhere, but they didn't show up in the photo <shrug>

I don't know how long I was out there with the angle grinder -- all I know is that we had just finished dinner when I went out to the garage, and when I came back in the house, my wife was already asleep! -- but I managed to cut all of this extra metal off the frame. I want to add a hoop to the rear of the frame to tie the two sides together. As I understand, that's best-practice for a cafe racer build, so I'll assume that those who have come before me knew what they were doing (not a big assumption -- it makes sense to me).

Here's the "after" photo, showing the new, lighter, trimmed-down aft end of the bike.

Next, I temporarily reinstalled one of the side panels. Ideally, I'd leave the side panels off, and trim the side panel mounting tabs to shave a little more weight off of the bike. However, then all of the electronics would be exposed and open to the elements. Unfortunately, the side panels extend beyond the down tube on the frame, since they initially were intended to cover the air box as well. I've removed the air box, so I don't need side panels quite this long, and IMHO, they ruin the lines of the bike. Consequently, I guess I'll need to fab up some custom fiberglass side panels as well as a custom cafe racer seat. I'm gonna need more foam...

At this point, I decided to call it a night. It's late, I'm tired, and...I ran out of things to do for now :)