Wednesday, 30 September 2009

Rear brake master cylinder.

My idea of keeping the bottom part of the original Husky frame, rather than fabricating that too, has so far proved to be a good one. Most of the fittings can be used "as is", and the engine mounts are already there, which of course saves time. However, since my new swingarm has a kink just after the bearings (number 1) it is now impossible to mount the rear brake master cylinder in its original place - since that space is now taken up by the new, wider swingarm. Instead, I have mounted it on the outside of the original bracket with the help of a couple of small spacers (number 2) that will be welded to the frame before I send it off to paint.

Despite the fact that is now sits a little bit further out, It's actually not in the way of my foot, but the relocated master cylinder necessitated a slight mod to the brake pedal in the form of a new, straight, tab at the back (number 3). The original was bent inwards. BTW: don't you just wish you could weld alu like that? Thanks Kent. The original brake line was waaay to long for the now much shorter swingarm and has been replaced by a new steel spun one. If I can muster the energy, I will try to replace some of the ugly hardware on the brake cylinder with some stainless pieces. Damn, there is not too many things left to do now. Next up: getting the chain line perfect.

Thursday, 24 September 2009

Brake hanger, part 3.

I got my brake hanger back today after my friendly fabricator Indiana had shaved off some 6 mm, leaving the full 15 mm only where the brake caliper bolts to the hanger. These are my findings on the subject of laser/abrasive water jet-cutting of thicker alu pieces:

"Daws" mentioned that the program I'm using – Adobe Illustrator – is not very good at generating AutoCAD-files and that the resulting curves are not as easy for the cutter head to follow as curves resulting from a proper CAD-application. And he does have a point. Looking at the cut surface (see image 1) it's obvious that the cutting head/water jet hasn't described perfectly smooth radiuses (radii?). It looks a littble bit as if the cutter head has paused/started/wobbled around a bit. This may of course be a characteristic of the water cutting method, but I suspect that it has something to do with the file as well. He also cautioned me that the cut surfaces won't be 100 "parallel" but rather have bit of taper - also a characteristic of the cutting method. Again, he was correct. It wasn't super obvious though and I'm not sure I would have noticed if I wasn't looking for it.

So, is it a worthwhile method? Yes and no. It's a quick and relatively cheap way of turning out pretty complex shapes without having to resort to more complex CAD/numerically controlled milling. On the other hand, the resulting pieces are nowhere near as perfect as pieces done using a mill. I spent three hours cleaning up and smoothing/straightening the edges in order to make it look like I wanted (see image 2). The surface isn't perfect yet – I'll leave the final polishing to the anodizers.

Conclusion: I think I'll save this method for thinner pieces in the future. And I'll use the freeware application "Solid Edge 2D Drafting" that Daws recommended.

Tuesday, 22 September 2009

I give up.

Damn that Pareto guy and his damned 80-20 rule. You know the one that states that "80 percent of a company's revenue comes from 20 percent of its products" or "80 percent of all speeding violations are committed by 20 percent of the drivers" etc, etc. In my case it's: "80 percent of the build time is taken up by 20 percent of the components". Make that "stupid small stuff that I hadn't expected to be such a hassle".

At the moment it's the speedo issue that's driving me crazy. The speedo drive turns the cable 2,8 revolutions for every revolution of the wheel (I've measured it). When I mention this fact to people who sell speedos, the line goes quiet. Then they start babbling that "Most Harley Davidsons..." or "I know that old Shovels use a 1:1 ratio..." or something else irrelevant (99,999 % of all aftermarket speedos are for Harleys, it appears). And when I add that I now have a 19 inch wheel (rather than the 17 inch wheel of the Ducati 996 that the speedo drive comes from) they tell me – in order to make me go away – that I will never be able to get the correct gearing ratio. And without the correct ratio the speedo won't show the correct speed. And that means I won't be able to get my M.O.T.

"Well, change the speedo drive then", I hear you say. But, alas, I can't. The front spindle is 25 mm and the only speedo drive large enough is the Ducati one I already have. I've thought about some sort of solution where I could machine the spindle down to something like 20 mm (so that I can use some kind of jap speedo drive), but then I need some sort of sleeve to thread over the the end of the spindle, in order for it to fit the forks, and I don't like that thought at all. And besides, I don't want to throw away my exquisitely machined, hollow, stainless spindle.

So. Enough is enough. I've decided to eat my words, and go with an electronic speedo. I've found one from trailtech. It's called Vapor Stealth, it's black and it's OK looking. The superbly helpful technician I spoke with (why are all US help line operators so genuinely helpful and friendly BTW?) informed me that the installation is quite easy and even the RPM tachometer graph works on my Husky (despite the fact that it didn't come with a tach to start with), using a simple lead that wraps around the spark plug lead.
Looking at my front disc I now realise that the good people at Braking had foreseen my failure to sort the mechanical speedo and have machined a little eyelet for the sensor magnet into the disc carrier. Hm...

Friday, 18 September 2009

Brake hanger, part 2.

Do you remember the abomination of a brake hanger that I showed you a while ago? Well, the time has come to make a proper one. This is how I go about it. There are of course a lot of ways that you could do it, but this is an easy one, especially if you are familiar with Adobe's wonderful vector-drawing application "Illustrator".

The prototype made from scrap pieces of steel (top part of image) is fundamentally correct, but has an awkward shape that I want to improve on. I also want to add some "meat" to certain parts of the hanger now that we're switching from steel to aluminium. So I put the prototype on a flat-bed scanner and place the resulting JPEG-file as a background image in a new Illustrator drawing.

Using vernier calipers, I take some really exact measurements of the real thing (length, width, size of the hole for the steel spacer) and make sure that the scanned image of the hanger gets the exact right size in Illustrator. Now that I have the scanned image as a background/template in the right size, I can draw a nicer looking hanger "on top of it" and still get the measurements correct and the needed holes in the right place (lower part of image). Once satisfied, I do a printout of my new hanger in 100% and check against my prototype.

Finally, I export the Illustrator file as an "AutoCAD Drawing"/dwg file and send it off to the laser/water cutters. If all goes according to plan I will receive a 15 mm thick alu part cut to my specification next week. This part will need a little bit of milling to get the right thicknesses (its thicker at the back) but it's still easier than doing the whole thing in the mill.

The reason why the hanger is a little bit longer than normal is that I want to be able to secure the "tuning fork" part of the hanger to the little stud inside the swingarm that keeps the hanger from rotating, using a screw. And in order for me to get to that stud it needs to be welded a little further forward on the swingarm – to clear the brake disc. The hanger will be black and most of it will be hidden by the black swingarm anyway so that's no problem.

Wednesday, 16 September 2009


Can anyone point me in the direction of a mechanically driven speedo that would work together with my Ducati speedo drive? I can't find one I like. This one from Deus is passable, but surely there must be a firm somewhere that specialises in old school mechanically driven speedos?

Tuesday, 15 September 2009

Star Bars.

Well, that's the name: Star Bars. Supplied by Outtacontrolla from his "Red Max Speedshop" at a very reasonable 80 quid including postage and packaging.

When I unpacked them my first thought was: damn they are REALLY wide. But once on the bike they give that flat special flat track look that is so hard to describe to people who never heard of the sport. And they look quite well made too. Glossy black [of course] anodising, matching the forks perfectly and with a really nice matte, almost crackelated finish on the "bird pearch" as we call it i here in Sweden. And what's even better: they don't have any ugly painted logos or anything like that. Just a small and tasteful "Star Bars" embossing on the central part of the bars. You see, we want the designer stuff – we just don't want it to be too obvious:-)

Sunday, 6 September 2009

Picture, thousand words, etc.

Now, if you've been in any way inspired by my little build and is currently sitting in your garage, espresso in your left hand and angle grinder in the other, thinking; hm, that old Gold Wing might look good with a new frame and some 19 inchers, then by all means go for it. But before you tear your bike to pieces, do yourself a favour and take lots of pictures, from all possible angles. Trust me, you will thank me later. I am at the moment trying to modify my wiring loom to fit my now totally modified bike, and the pictures I took before starting the disassembly are really worth their weight in gold (if a digital image actually weighs anything...?).

On a side note: looking at my "before-pictures – what a terribly messy job the Italians did with the wiring on my original Husky! It looked like a Calcutta street corner, loose wires hanging everywhere. I promise to do a much neater job this time around.

Wednesday, 2 September 2009

Angle of dangle, part 2.

I've said it before, but it bears saying again: it's a good thing I don't do this for a living. I've been dicking about with the angle of the muffler and the connecting pipe now for days, without finding that elusive, perfect solution.

I tried the shallower, scrambler-looking position (see last post) for the muffler for a couple of days, but I just COULD NOT get the
link pipe between the 2-into-1-pipe and the muffler to look good. The angle and curvature of the link pipe clashed terribly with the angles of the frame. It looked like an afterthought (which in essence it was - but don't tell anyone...). I now have a whole heap of discarded pipes on my work shop floor, and a new-found respect for people who make exhausts as a regular job.

As you can see, I have now gone with a much steeper angle for the muffler, which makes the link pipe much easier to get right. It's now parallel with the support strut for the seat and doesn't break with the overall lines of the bike. The increased angle (which was suggested by "Outacontrolla" BTW) actually looks more flat track than Scrambler as well. Or is this just my brain trying to justify my decision to give up on the other position? Hm. Next up: moving the mounting point for the muffler a little bit backwards and fabricating a little hanger to replace the strip of duct tape. I don't fancy the "clamp hanger" that came with the muffler.