The riders arrived in LA in one piece, after a long cross country trip. Here is a pic of my old bike, the “Steel Butterfly” and “The Mexican”. I My friend John owns the Steel B.
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The customer who commissioned the Efab bike “The Mexican”, has spent the last 10 days riding across the country with his friends. It makes me proud to know he is out there enjoying his bike!
Somewhere in Wyoming…
In between various customer projects, I have slowly been making progress on my engine. The Heads are twin cam 88 originally, but have been modified. I reshaped the majority of the fins, rounding them around many of the sharp edges. Here is an overall view of the cylinder, head, and rocker box mocked up.
A typical twin cam has aluminum cylinders with an iron sleeve pressed into it. I had Randy at Hyperformance make me billet iron cylinders. The advantage being that there is no way for the iron sleeve to become loose in the aluminum cylinder, because it is all iron! These are secured by a “head and base” stud setup, much like a knuckle, pan, or shovelhead would have been. Here a set of 4 studs hold the cylinder to the crankcase, and another set of 4 hold the head to the cylinder.
An evo or twin cam, traditionally, used a set of 4 studs that ran all the way through the head, cylinder, and into the case. This is a simpler way to attach all the parts, but not as strong.
In addition to the stud conversion, I have adapted the heads to use a superior head gasket method, the metal o-ring. On a stock twin cam (or any other harley) a composite flat gasket was used, sandwiched between the head and cylinder. They work fine, but can blow out if extreme cylinder pressures are achieved. The metal o-ring setup eliminates the flat gasket, instead using a series of steps machined into both the head and cylinder, with a copper ring integrated into it. All of the mating surfaces make contact with each other at the exact same time. This requires extremely precise machining, but results in a nearly indestructible union. I can only assume, too, that heat transfer between the head and cylinder will be improved, due to the metal to metal contact.
Here is the top of the cylinder. The surface rust inside the bore will be gone when the final honing happens.
You may have noticed that there are no oil drain passages in the cylinder. This is because I have re-routed them to the outside of the head and cylinder. This is good for 2 reasons. One is it keeps the oil cooler, since it is not touching the approx 300 degree cylinder walls. The second is that there is no chance of oil weeping between the head and cylinder surfaces, since it bypasses that area completely.
I had to machine a passage through the fins of each cylinder, through the wall, and into the oil drain passage inside the head. This was then tapped for a custom made fitting. Obviously, the original hole underneath has to be plugged as well.
Here is the stainless drain fitting coming out of the head. It has a 6 AN fitting on the end for hose attachment…
I have also added compression releases to the heads. Compression releases are simply tiny valves that allow the cylinder pressure to be bled off as the starter motor rotates the engine. This takes a huge strain off the starter motor and battery, and they simply pop shut when the first combustion occurs, allowing the engine to start. It is unusual to see them on motors with small displacement, but there is no downside to using them. Also, my compression ratio and the resulting cylinder pressures are far higher than either a stock evo or twin cam, so despite the small displacement, the starter will still need all the help it can get.
Installing compression releases is easy with the right tools. It requires a precise hole to be drilled and tapped, which enters the combustion chamber between the exhaust valve and the spark plug hole. More to come…
After a brief hiatus I am back on the “mini stroker” chopper project. I decided that it was the right time to make handlebars. The first step, for me anyway, is to make a wire form of what I want so I can hold it up to the bike and get a visual. This is not a precise thing, rather just a basic reference. I know roughly how much rise I want, and know roughly the whith, but that still leaves a lot of room for creativity.
I am making these bars out of 304 stainless steel, 7/8″ OD, .120″ wall thickness, seamless tubing. I will end up using about 4 feet of it, approx $80 worth of raw materials. This is opposed to the catalog bought, .049″ wall, recycled mild steel, chromed Chinese bars found on most “custom bikes”.
I start with the center bends and work outward. I have reference marks drawn on the tubing. This is so I can take the bars out of the bender, check them, then put them back in the exact same location for further bending. Speaking of bending, this is my bender. It consists of a typical bottle jack and various mandrels, a few of which I made specifically for tight radius handlebar bends.
For tight radius bends like these, I use two different mandrels, a gradual “starter” mandrel and a secondary tighter one.
The hardest part of making bars is keeping everything symmetrical. The exact location of the bends, the angles relative to each other, equal pullback on each side, etc. This is all done through bubble levels, angle finders, and measuring them against a flat table. There are a minimum of 6 mandrel changes, each of which entails some dis-assembly of the bender. Oh yeah, the material is springy, so I have to “overbend” each bend past the point I want, then let it spring back slightly to where I want it.
Almost done with the bending stage….
The next stage is polishing them. Sounds easy enough but keep in mind I cant just go straight to the buffer- First I have to sand them. The buffer can only take out microscopic scratches, not the deeper ones left from the manufacturer. For that I need my trust Burr King sander, set up with a slack belt, and a variety of sanding grits.
Not a great pic I know, but trying to simultaneously sand the bars and take a picture was not easy. Same for the buffing. Needless to say there were about 2 hours worth of sanding and buffing to get them to a mirror finish level.
I threw the grips on there to see how it looked. I am happy for now, but there is always the chance that they will need further modification as the bike evolves.
I’m sure I will get many comments on my “sweet chrome apes” from the local do-rag crowd. Followed by “how much for a set uh dem?”. Followed by a look of disgust and confusion…
I recently returned from another trip to the legendary Carls Cycle Supply, home of Matt, Miss Brittney, And OG Carl.
(pictures are all from my dirty I phone, so they aren’t great)
I had previously helped Matt on his Born Free 4 winning knucklehead, so I was honored he asked me once again to come help with some fabrication on a new project. This project, unlike the knucklehead, is a type of bike I was not previously very familiar with- a 1923 Harley race bike. Though it has a similar motor to the bike Matt raced in the 2012 “Cannonball”, every other part is completely different.
The bike is for his wife, the lovely Brittney, who plans to race it in a series of vintage dirt track exhibitions, along with many other period bike enthusiasts. What makes this bike especially unique is the fact that it has no transmission, and no brakes! It doesn’t have a starter either, or any clutch. It is about as “chopper” as it gets really. This is the style of bike that would have been ridden on either wooden tracks (aka board track), or later in the 1920′s, oval dirt tracks.
After a series of delays and layovers thanks to Delta, I made it there. First thing to make: a seat…
Now, keep something in mind here; Matts shop is a restoration shop. He and his dad have been building 10 point perfect (and I mean perfect) knuckleheads and panheads for many years. However, it is not a shop set up for heavy fabrication. This means that the tools I am used to using are not available. This includes brake, shear, bandsaw, plasmacutter, plannishing hammer, fixed dollies, and sander.
That doesnt mean I can’t work, but it does mean I have to get a bit creative with my methods.
With a sandbag and some hand dollies, it is possible to make most basic sheetmetal shapes. This is also a good reminder to new chopper builders that you don’t have to have a ton of expensive tools to make bikes, just some patience and ingenuity.
They do, however, have an awesome mill. Here I am using it to rough out a seat pivot from a block of aluminum I found..
Here is one of the inner tank panels- the easy part…
The tank design is 2 piece, hanging over the backbone of the bike on piggybacked strips, bolted directly into the tube.
The design for the tanks is very mailbox looking; square and boxy but with radiused edges. This immediately made me nervous because trying to keep thin sheetmetal panels dead flat (while curving the edges) is almost impossible! You see, flat sheetmetal is very weak and becomes warped as soon as any part of it is welded. When sheetmetal is formed into a curved shape, it gains body and becomes stronger. This time I had to keep about 80 percent of the tank panels flat, while curving and welding some areas. Did I mention This thing is going to be polished raw metal? ughh
They didn’t go for my paint scheme.
Here they are welded and hand sanded to about a 100 grit level.
Now they are down to about 600 grit..
We decided, partly due to time restrictions, to paint the top and side panels of the tank the same color as the frame, and only expose the polished sides of the tank. This was a relief because it meant I could rely on a small amount of bondo to smooth the welds around the gas caps and mounting strips.
The tanks will be sealed before the final side polishing occurs. I left that in Matts capable hands.
I also made a basic sissybar out of steel round stock, and made a little oil tank, which Matt later finish welded and added fitting to.
Then I was back on a plane, headed home after another great trip!
I have been committed to a trailer fender for this bike since the gestation. I have never used one, but always thought they were cool on the right bikes. I like that before there was a huge chopper aftermarket, this was one of only a handful of options for the home builder.
I stuck with stainless steel throughout the process, polishing it as I went. Fender, struts, bolts, etc. Many people ask why I use stainless steel instead of chrome, a good question. For me, the main reason is durability. Chrome is only a paper thin coating of metal, bonded to the surface of the base metal. While extremely hard, chrome has a tendency to flake off, especially ”show chrome”, the type used for cars and bikes. Stainless is not a coating, so it cant flake off.
The second reason is that chrome interferes with part fitment. When two parts have to interact (bolted together), I like metal-on metal contact, which means two perfectly flat surfaces against each other. I try to never have chrome, paint, or powder-coating between two parts. The reason is obvious; as the bike flexes and vibrates, the weaker material will break down and compress, leaving you with a loose connection.
Third is because chromers are, frankly, a pain in the ass. It costs a fortune to get a bikes worth of parts plated- far more than the cost of the raw material in stainless. It is not unusual to have a frame plated for $3000, and within a year all the welded areas are rusted. And the time factor too, weeks and weeks waiting, can be very frustrating. Its another sub-contractor, and another variable, that I don’t need to deal with. There are good ones out there, but they are hard to find. I’m sticking with stainless.
What I decided to do was mount the fender using a flange at the back of the toptube, and two struts per side. The fender itself is 13 gauge stainless, and combined with the 6 mounting points, should be quite secure. Here is the flange, about halfway through the process of machining. Prior to this pic I was in the lathe. This part started out as a 6″ long by 4″ round solid chuck of steel.
The surface you see here is slightly concave, which matches the surface of the fender perfectly.
For the fender itself, my usual routine is to make bungs or tabs that the struts can attach to. These are usually welded to the sides of the fender. I thought that if they were actually one solid piece of round stock inserted through the fender, they would be far stronger, as well as perfectly symmetrical. This bike afforded me that possibility because I wanted the fender to be mounted high above the tire. This gave me the clearance I needed. Here is one protruding out through the fender side. I have tack welded it, and will do the final weld later.
The rods were milled out for the portion under the fender to increase tire clearance and save some weight.
What is the downside to stainless? It is hard as hell to work with! It is extremely hard on tools, warps like crazy when welded, is expensive, and hates to be formed in any way. If you want it shiny, or even a consistent matte finish, I spend hours prepping it. This can involve hand sanding, bench sanding with an orbital sander, using the Burr King heavy sander, or abrasive cutting compounds on the buffing machine.
Here are a few pics of the strut making process. They have been sanded to about 500 grit in this pic, and will be sanded more, then buffed:
This part was a bitch to get symmetrical- the top section of the front struts.
Here she is now. The fender isn’t fully polished, because I still have to do the final weld around the rods. The strut sections have been polished piece by piece, because there will be no way to hold the entire assembly up to the buffer. The back of the seat will be attached to the front strut assembly.
strut to frame mounting
Next post- seat pan making….
Finished the axle adjusters for the new bike. I have done many different types on my various bikes, usually trying to re-invent them in some original way, but this time I chose to do a more conventional style. That being said, I tried to make them very strong, accurate, and made of stainless steel.
The nuts are billet stainless with a self locking ring built into them. They don’t wear out after repeated use like a nylock nut, and are more secure than a lockwasher.
I also made some progress on the frame. Next step is the fender mounting.
Trans is finished, except for one block off-plate I still have to make.
The front motor mount.
This coming weekend (Jan 19th/20th), I will be at the IMS show at the Javits center in NYC. I will have Icarus with me! come check it out.
This is the first batch of gen 5s. These are the best yet. I have listened to feedback from guys running the gen 4s and taken measures accordingly. Price has gone up $25, but the materials are better. $375 plus shipping. These are weld on. Many people have asked how to weld them to a regular steel frame, and its easy, just use 309 filler rod. It welds the same as regular steel- no special skills required.
These are designed for kickstart bikes, as a response to typical cheap-shit weld-on stands snapping from the bouncing. Remember, you don’t look cool when your stand snaps off and you faceplant into your air cleaner, as your paintjob gets smashed into the pavement! And, of course, there will be people watching when it happens. Get a leafer and never worry again 203 315 9908