Just a little sprocketing

I mentioned some time ago that my Dad is rebuilding a Suzuki RE5.  The frame is set up to use later Suzuki Katana wheels.  Things like this are rarely a direct swap.  In this case, aside from basic wheel fitment issues, the Katana is made to use a 520 size chain, while the RE5 uses a 530 chain.  Swapping the RE5 to a 520 chain is pretty straight forward, but you need to buy a matching front sprocket and a chain.  It was decided that it would be easier to just adapt the RE5 rear sprocket to the Katana hub. 

The first thing I did was drill the new bolt holes.  In stead of doing the math to figure out where to put the new holes, I just drew up the bolt patterns in Solidworks.  From that, it was very easy to measure how far from center in X and Y the new holes had to be.  After center finding the hub hole, I drilled all the new holes.

Here you can see the new holes.  One new hole overlaps one of the old holes.  With a 5 hole pattern(RE5) and a 6 hole pattern(Katana) so close in diameter, you will always have an overlapping hole somewhere in the pattern.  On something like this, it doesn't make much difference.  Even a modern high power 2L sportbike doesn't have anywhere near enough torque to shear off the bolts. 

Then I set about enlarging the hub hole, it needed to be opened up by about 1/4".  The easiest way to do this on a manual mill is with a boring bar.  I had a whole long explanation of how these things work and how to use them, but it was just boring...

That's really all there is to it.  I don't have a pic of the RE5 sprocket on the Katana hub, but it fit like a glove. 

H1 , Chapter 6.

The next chapter of my H1 build has lots of nifty stuff in it.  At this point, I'd gotten most of my engine back together, and have most of the shiny bits bolted back on. While I was at it, I put some stiffer clutch springs in. Fortunately, it seems as though the clutch it's self was replaced not to many miles before I bought the bike, so it didn't need to worry about that.

With most of the bike it's self down to painting and bolting stuff on, the rear fender is the last big "fabrication required" project. A plain smooth fender like I've got is fine for a race bike, but this one will be street ridden. That means it's going to need blinkers and a tail/brake light. I started planning them as soon as I started planning the fender. I didn't want them to look like tacked on afterthoughts like you see on so many customs, and even a lot of factory bikes. I explored lots of options. What I decided on is very custom, very visible, and most importantly don't stick out like sore thumbs.

The blinkers are made out of 1/2" Lexan. I cut 1/2" off the bottom of the fender, 'glassed on some tabs, bolted the Lexan down and sanded to shape. I then ground out the back sides for some LED strips. I've got 21 LED's shining out through the Lexan. More on the blinkers later, but here's a rough pic so you get the general idea:

Next up is the tail/brake light. This one took some finesse to get looking how I wanted. It's a straight forward process, but involves a lot of fitting. Like the blinkers, this lens is going to sit flush with the fender so it doesn't interrupt the lines.

I'm using the oven method of plexiglass forming. I'd like to use Lexan, but it's not as forgiving as plexiglass when baking it in the oven. First thing I did was make a plaster cast of the back of the fender. I just used some modeling clay to make the walls after I'd figured out what size and where I wanted the lens.  Mixing in some plain white Elmers glue will greatly increase the strength of the plaster.  You don't need much, around 5%-10% of the water added to the plaster mix works well.

I let the plaster cure/dry out for about a week. It can take awhile for all the water to finally evaporate out of the plaster.  warming it in teh oven can help too, as long as you don't heat it up too fast(or it could crack).  Then I cut a piece of plexiglass, set it and the plaster mold in the oven and baked it at 300*F for 10 mins or so. It gets soft enough that, with some gloves on, you can smoosh the plexiglass into the plaster buck. It took a few re-heats to get the shape just right. Also, you can see the pencil on the plaster, that's about where the lens is on the fender. I found that if you draw it straight on the fender, the pencil line will transfer nicely to the plaster.

With some rough trimming, you can see how well it conforms to the fender.

The next part take a lot of grind, check, grind. Took me about a day of messing around to get it perfect. Once the hole is cut in the fender, the lens can be cut, ground, filed, and sanded to fit just right. When you're done, you've got a custom flush fit lens that perfectly matches the contours of the fender.

Then I dyed the lens. It's pretty easy, but it took a few test pieces to get the time & temperature right. Plexiglass can be easily dyed any color you want with Rit fabric dye. The secret is to heat it up. If the dye is to cold it won't take, if it's too hot the plexiglass can get soft and warp. Just under boiling seems to work best. I've had the best results with the dye heated on the stove to about 190*F, and a cook time of around an hour. More or less depending on how dark you want it, and a meat thermometer works great for watching the temp. The same process works for dying the clear fuel line the color of your choice.

If you want to use Lexan(polycarbonate) instead of plexiglass, there are a couple things to note.  First, Lexan absorbs moisture like a sponge.  If you just try to heat it to it's forming temp, you will end up with plastic full of bubbles.  This is caused by steam forming in the plastic and having nowhere to go.  You MUST pre-dry Lexan before forming it.  The general rule of thumb is to bake it at 250°F for one hour per .010" of thickness, so 1/8" Lexan should be baked for 12.5 hours.  Second, Lexan forms at a much higher temp than plexiglass.  It needs to be heated to around 375°F to be moldable.  Third, You cannot dye Lexan, it just won't work.  If you want some color other than clear, you either need to start with that color plastic, or use one of the few paints on the market that will stick to polycarbonate(regular spray paint won't stick well).  The paints made for RC car bodies(NOT standard model paint) are made for polycarbonate and are available in translucent colors.





Now, back to the blinkers.  The first thing I did was get one of THESE $10(shipped!!!) 40 LED 3rd brake lights(and if you don't shop DealExtreme, you should. They have all kinds of nifty stuff at dirt cheap prices. Shipping is sloooooow, but it's free.  The price you see is the price you actually pay, no extra shipping or handling. Stuff is so cheap, you can't afford not to buy it :D  http://www.dx.com/p/40-led-third-brake-tail-light-for-vehicles-12v-10524#.Vf97V5cqvXw

Then I opened it up, and cut the circuit board in half, giving me two 20 LED strips. I got out the Dremel and ground a slot in the back of the Lexan for the LED strips to sit in. Unfortunately, Lexan(polycarbonate) doesn't dye like Plexiglass does. The dye just doesn't take. I tried some other things, but couldn't get consistent results. That means I had to paint it. I used white, then black on the top(the white base coat helps reflect any stray light). I used SEM Color Coat, which sticks to Lexan fantastically.  The edge and bottom are painted with Duplicolor's Metalcast red. It's basically a red tinted clear in a spray can, made to give chrome an anodized look.  It also sticks to the Lexan like a champ.
http://www.duplicolor.com/products/metalCast/

Here's how it looks. It's just taped together for now, the final pieces will be siliconed together to weatherproof the circuit board. It lights up nice and bright, and reasonably evenly. The dark strip is one of the bolt holes through the Lexan. You can't really tell in the pic, but unlit, the lens is a nice deep red.  Off:

On:

Just for kicks, here's what the blinkers look like lit up when they're installed.

That's all for this chapter.  The end is approaching... :)

H1, Chapter 5

More work on the H1.  The pic doesn't really show, but the fins aren't just sanded clean, but fully polished. The paint and sand the fins trick works nice and is pretty quick, but having to actually fully polish the edges of the fins turned out to be really time consuming.

More shiny bits.  I still have some final buffing to do, but I ran out of polishing compound.  I also left the big gouges and scrapes. There's not enough metal left in some of them to sand out. And they character and are a nod to the bike's previous life(but mostly I'm just lazy).

You'll remember I flipped the headlight ears upside down to get the headlight lower. The point of that was to get the gauges mounted lower. I finally got that part done. The pod still uses the same mounts, it's just on the other side of the top triple clamp. I had to cut off then drill out the factory studs on the bottom of the pod. Those studs are cast in so the won't come out, and they're harder than @#$%(for no apparent reason). Took me 2 hours and many drill bit resharpenings to get the holes drilled through. Then it was just a matter of trimming the center cover to clear the triple clamp. I'll seal it up when I do the final assembly. I'm still using the stock rubber mounts, and some stainless bolts that I'll polish nice and shiny. The ignition key still works just fine, and the pod sits like it was made to be mounted there.

The gauge pod was the last of the major "before it comes apart" fabrication.  With that done, I stripped the bike down as far as I'm going to. Once I get everything cleaned, I'll paint the frame, swingarm, and engine case.  Just pulling the forks off really transformed it from "most of a motorcycle" to "a pile of parts" haha.

Got my frame cleaned and painted(and yes, I took the rear wheel off before I did it).  Most of the factory paint was still in very good condition, so I only painted the parts that are visible when the bike is assembled.  It also saved me the trouble of having to strip off the wiring harness.  I've seen lots of black cylinders on H1s and H2s, but I don't know that I'd ever seen an engine with black cases. Since I've got a black and shiny theme going on, I decided the cases should be black too. I also put a fresh polish on the rear brake drum while I had the wheel off.

H1, Chapter 4

Let's start this one with a quick pic. The trimmed part in the pic is actually the first mold I made(you can see the shiny inside). It's trimmed the way it is so that when you lay a part up in it, it leaves a very distinct line to follow when trimming the actual part. Having a guide saves a lot of time down the road. You can also trim the part while it's still in the mold, using the trimmed mold as a guide. That's what I would have done here, but I wanted to be sure this part was going to come out of the mold.  The part it's self gets trimmed with a cutoff wheel in the 4 1/2" grinder.  It gets rough trimmed, then the edges are sanded to their final shape.

Got'er trimmed and sittin' on the bike. I fit on it exactly where I wanted to, nice and comfortable, and not so upright.  You can see as well that the rear mounting tab of the tank actually sits on it. That's part of the plan, makes the tank sit where I want it as well as provides a front attaching point for the seat/fender.

Truth be told, I barely got the fender out of the mold.  I had to fight like heck with the thing to get it out of the mold.  Since the whole point of the mold was to have an easily reproducible part, I wanted something better.  So, I used my newly molded fender as a buck to make another new mold.  Like the original mold, the fender gets bodyworked, recoated in resin, and polished to help keep the new fiberglass from sticking.  In order to get the parts out of the mold easier, I decided a two piece mold was the way to go.  It's actually not a whole lot more involved than a one piece mold.  A piece of particle board gets hot glued to the buck where you want the seam to be, then you cover half the buck with fiberglass:

Once it's set, you pull the particle board off and you're left with half a mold and a flange:

Then you prep the other half of the mold and lay it up against the flange.  Before pulling the mold halves apart, it's a good idea to drill some bolt holes through the flange so they're in prefect alignment.  While I was at it, I also made molds for the seat pan, and fender undertray.  For the seat pan mold, I used modeling clay to create a gap on the seat pan lip so there's room to wrap the upholstery around the fiberglass.  I also used clay to fill the rear tank mount to lay up the seat pan mold.

Here are the three molds all ready to go:

With all 3 molds made, I could finally make part #1.

I got it trimmed and fit to the bike. I trimmed the seat area out, bonded in the under tail piece. I also glassed in some steel tube that will serve as a support for the front seat/fender mount. The same hole also serves as the rear tank mount. The rear fender mount uses stock tailpiece mount holes, and the stock splash guard still fits with some minor trimming.

The COOLEST part of this whole project is that unlike ALL the other cafe style fenders available on the market, the stock seat hinge and seat latch STILL WORK. The storage area in the tail is specifically sized to hold a can of starting fluid or quart of two stroke oil. Even the helmet hook still works :)

Got the fender primed and rough blocked, and moved on to other stuff. I did some minor porting on the cylinders. I also made myself some UFO's.  If you've never heard of UFOs, they are little plastic pieces that fill in the bottom of the slide on slide type carburetors.  They are worth a few percent HP gain on 4 strokes and are generally not worth it.  On a two stroke though, they can often add 10% more power and you generally get better low and midrange throttle response. They are commercially available, but of course they don't make them for my specific carburetors.  So, I made my own.

I got a chunk of UHMW from e-bay and went to carving with the dremel. Took some time to get the shape right so the slides would close all the way, but after the first one, it went quickly. You can't really see it because of the white plastic, but the shape is really quite swoopy. With the stock and UFO'd slide next to each other, you can really see how it helps airflow through the carb, especially at lower throttle positions.

Then I moved my headlight and gauges. I never liked how high the gauges stuck up above the handle bars.  It was even more noticeable with the drag bars. The gauges sticking up interrupted the flow of the lines of the bike. So, I decided to move everything down.  This turned out to be a super easy mod. 1: flip the headlight ears upside down and swap side to side. 2: cut off gauge pod studs and drill out gauge pod for bolts. The gauges nest perfectly on top of the headlight, and will use the stock rubber mounts with some through bolts. It brings the gauge pod down to the level of the tank, much more gooder...er better, much more better...  If you compare it to my original profile pics, you'll see how big the difference is. I'm not quite done, that's as far as I've gotten with it, you're all caught up through today.

The big kick off!

To kick of this chronicle of the semi-random things I do, I thought I'd post one of my my proudest achievements.  It's the only project that I've ever actually dubbed "finished."  It's the build of my 1975 Kawasaki H1 Cafe Racer.  If I get to it, I'll post the whole build long.  For now, enjoy :)