Transmission and Axles

The transmission was the next big step to making the frame into a rolling chassis. Since VW designs their vehicles to have the motor in the back the axle runs through the transmission. There was a part number on the frame and we were able to determine the frame is a 1954. This means we would need a transmission modified, since the size of the transmission changed in 1966. I shopped around and ordered what we needed at the best price. It was supposed to take 3 weeks to arrive. It took seven.

I also ordered axle rods and axle tubes to go with it. I knew I was buying used axle tubes. Both tubes used were less than 1/3 the price for one new one. However, when they arrived I was surprised at their condition.

It was clear by their appearance they had been on the ground under the vehicle and years of weather had caused them to sink into the asphalt. I used the metal grinder with a wire wheel brush to get the big chunks off. A—was gracious enough to take the parts to work and sand blast them so they were clean and pretty.

Next we discovered despite careful research and ordering the right modified parts to fit our frame, the transmission did not bolt in correctly. I took pictures of the problem and posted questions for the experienced minds on The Samba.com as well as sending them to the guy I bought the transmission from. Eventually, Ry—coworker Ru—said the bracket the transmission was supposed to mount to looked like it had been welded on poorly. Sure enough…

C—cut it off and mounted it to the transmission. Then we carefully slid the transmission into place and bolted it to the rest of the frame. Once it was properly positioned C—re-welded the bracket on and then we were in business.

However, because of the design of the transmission the axles and axle tubes have to be put in and on the transmission first before it can be mounted to the frame. So we unscrewed the bolts and carried the transmission to another surface. This is what the transmission looks like without the gears or axles.

The problem was I forgot to order the parts that connected the axle to the transmission. I had all the parts that went from the outside of the axle tube to the wheel rims. I had no idea the differential gear and fulcrum would not come with the transmission. So another call was made, more money was paid, and time elapsed until the parts arrived. 

Finally, the fulcrums go inside the differential gear, the differential gear goes inside the transmission, the axle rods go inside the fulcrum, the axle tubes go over the axle rods, and the whole kit gets bolted to the outside of the transmission. Ta-Da! We are in business.

Here is a view of the transmission with both axle rods and tubes in place and the transmission mounted from the front of the frame.

Here is a view of the transmission mounted with both axles and axle tubes mounted from above the frame.

Just getting the transmission bracket welded on and the parts assembled and mounted took all day. We will have to save adding all the parts that go between the axle tubes and the wheel rims for another day.

I had hoped to have the rear wheels on in early March over my Spring break but that clearly did not happen. The transmission didn't arrive until Easter a month later but even then we did not have all the parts. 

Next step adding the bearings, shocks, and braking system. 

Oh... and in case you are wondering, the tag hanging from the transmission is to remind us there is no oil in it

:-)

Gas Tank

VW trikes differ from other 3-wheeled motorcycles by the fact that VW engines are in the back. This means that these vehicles have a tendency to be heavier in the rear and easily pop wheelies. Traditionally in the past VW trikes have had a gas tank mounted in the back near the engine. One classic design is using a Moon-Eye tank.

This is often used by sitting on top of the VW motor.

As a means to prevent wheelies we are trying to add additional weight to the front of the trike. One of the ways to do this is by having the gas tank up front. The down side of this is that many motorcycle gas tanks only hold 2-5 gallons of gas. I wanted to purchase as big a gas tank as possible to add more weight to the front end. Plus with a bigger tank I can go further without fueling up.

Keeping with the classic vintage look of the frame I went with a tank that is designed on airplane fuel tanks. I also decided to use tanks that were split and designed to rest on either side of the frame. 

However, these tanks required some modification because of the design of the frame. We already re-enforced the junction of the frame with the neck. Now we attached the tanks to the frame itself.

First we welded just a couple of places on one tank. 

Then we lined up the second side with the first and added a couple of tacks to hold the other one in place

Then the edges of the tanks (now that they were positioned evenly) were welded to the frame.

Finished welds

The next step would be to grind down the welds so they look smooth. Then to add Bondo to blend the parts together seamlessly and paint it with primer.

First you add the Bondo to fill in the gaps and crevices. 

The Bondo is sanded down and additional layers are added to fill in any imperfections.

The Bondo is used to level out the parts to make the tank and the frame seem like one seamless piece.

Then the whole area is sprayed with primer. Notice the tanks are no longer shiny bare metal.

Ultimately, the tanks and fenders will be painted midnight blue metal flake and the body of the trike will be silver.

Reinforcing the front end

As I mentioned in my previous blog VW trikes have a tendency to wheelie. To take extra precaution to keep the frame intact we added extra sheet metal plating to the front intersection of the neck with the body.

This is the original neck with plating in the joint.

This is the new neck piece with adapted joining plate.

Here is the new front end with reinforced steel plating welded on.

Here is the final piece that has been ground down and is now ready to weld the tanks on. Once the tanks are on the plate will be covered with Bondo to hide the seams, sanded for a smooth finish, painted with primer, and finally painted with color.

Here's me in protective mask and goggles sanding down Bondo in case you were thinking C was doing all the work  :-P   It was cold in the shop so I'm wearing a beanie too.

Front End

As I mentioned before, one of the things that give choppers their cool look is the rake of the front end (how far the front tire is from the frame). In the old days bikers would cut the front end from the bottom, bend out the front axle until it was where they thought it looked good, and then stabilize the weld. Well, nowadays we know their is trigonometry and physics involved. I needed to buy a front end (as cheaply as possible) that would not only go with the look of my trike, but make the math work too.

I started by looking at modern Harley Davidson trikes. I gathered specifications for all the frames they used to create trikes. I decided to go with the FXFD Fat Bob. I wanted to use parts that would be easy to find. I wanted to use a front tire that would be compatible with a wide front end. The Fat Bob had what I was looking for.

Most chopper front ends are sold based on length. They are marketed as +2, +8, +14, -2, etc. This means that they are two inches over, or two inches under market length. Market length is 29". Using my online triangle calculator (mentioned before) I figured out I needed to buy a +6 over front end.

One of the issues with VW trikes is the VW motor sits in the back. This means most of the weight is behind the driver. Since VWs are rear wheel drive the combination with the weight in the rear means that the trikes tend to pop wheelies. I needed to buy a front end that was heavy and would handle being slammed into the ground after a wheelie. Some biker enthusiasts would argue a classic springer front end would provide more shock absorption and wheelie impact.

  However, I didn't like the look of the springer. I preferred the look of a glide front end.

However, these would be less resilient to rough roads and slamming down after a wheelie. So I decided to go with a more modern look which is known as an inverted glide. Instead of the front end forks being thicker at the top they are thicker at the bottom. I combined this with a wide front tire to go with the wide VW bug tires and ended up with a pretty classic look.

It is called an Inverted Wide Glide. We haven't hung it on the frame yet, because we want to get the tanks welded on and the frame painted, but in case you're wondering what it might look like...

Even though you're just eyeballing it in this little picture you can see the shock absorbers and springs are hidden inside the tubes, which is the design of a glide front end. You can also see how the fat tubes of the inverted wide glide work well with the frame it is next to.

Rake and Trail

One of the things that gives choppers their cool look is a raked out front end. The rake is the angle of the front fork from the body. Think of it this way... if you draw a line directly down from the top of the frame to the ground perfectly perpendicularly this is the 90 degree angle of your right triangle. From where that line (or plane) hits the ground to the spot beneath the front wheel is the second side of your right triangle. The line that goes from the top of the frame to the wheel is your hypotenuse.

So before I knew what kind of front end I needed to buy and what size to get we had to figure out what the rake was on the current frame. If a chopper has a front end that is too long the bike (or trike) won't be able to make a U-Turn. Those of you with big cars with a crummy turning radius can relate to that.

Now there is physics and trigonometry involved in the front end rake of a chopper. Due to the pressure of the vehicle and the resistance of the ground the front wheel wants to spin not round and round north to south but round and round horizontally. For a chopper to be safe the physics must be right so that at both low speeds and high speeds the front wheel does not have too much side to side wobble, nor does the bike (or trike) have the propensity to try and flip ass over front end.

Years of practice, and eventual mathematical computation has taught chopper builders that the ideal rake is between 30-45 degrees. Old bikes where the rider sat upright had a smaller degree of rake on the front end. New high speed "crotch rocket" motorcycles often times have less than 28 dgrees of rake on the front end. The typical Harley Davidson motorcycle has between 28-32 degrees of rake.

C gets out his old school engineering tool, the plumb bob, and hangs it from the neck of the trike frame. I stick a piece of doweling in the neck for visual effect.

As the plumb bob hangs perfectly perpendicular to the ground due to gravity we have the back leg of our right triangle. Based on the readings we learn that this trike frame has a front end rake of 53 degrees. That is too much. We will have to adjust the rake.

However, making a chopper safe to ride involves more than just what angle the front end rakes out from the frame. I can use a right triangle calculator (because I suck at math) to figure out how long a front end to order, but we also have to worry about the trail.

Trail is the horizontal distance from where the steering axis hits the ground (our perpendicular line) to where the front wheel hits the ground. The trail is calculated in inches. The greater the amount of trail the more stable the front wheel is but it also makes the wheel harder to control. If the trail is too small (or negative) the chopper will have little to no wobble at low speeds, but be difficult to handle at high speeds. If the trail is too great the chopper will handle sluggishly at high speeds but will wobble at low speeds. To have a safe ride that is easy to handle 2-4 inches of trail is ideal.

To figure out the trail of the front end once you know the rake you need more than geometry (like we did in our right triangle exercise). It requires trigonometry.

Now, as you recall I mentioned above, I suck at math. Luckily, not only now thanks to the internet do we have online triangle calculators, but we have rake and trail calculators.

We knew we would want a maximum rake of 45 degree angles. Besides, that would be easier to build than a 42 or 44 degree angle. With a simple right angle triangle ruler we had a measure for where the neck should go.

Step #1 level the trike

Step #2 measure 45 degrees and mark frame

Step #3 cut down neck angle (since we had to replace the neck piece entirely it was cut off)

Step #4 weld new neck on at proper angle

This is not the final finished piece, but it is as far as we got that day. There will be more welding to reinforce the strength of the neck. VW Trikes have a tendency to pop wheelies so we want to make sure the neck is strong enough to handle it.

Just behind the frame you can see a piece of sheet metal up against the wall. We will use metal from that to blend the center piece between the tubes of the frame to make it cleaner and stronger. Eventually most of this will be covered by the gas tanks.

The frame

I was so excited when we got the frame back to The Shop. The first step was going to be sandblasting the frame down to its bare metal. I was told by C that they had a sandblasting machine at The Shop and I just had to get the material for it.

I went to The Pep Boys and bought an enclosed carport canopy and went back to The Shop to try and convince C and his brothers to help me assemble it. Once it was up we went down to Home Depot and bought an industrial power strip some clamp lights to make the carport a useable space, after all winter was coming. Even if it is Los Angeles we still have to deal with darkness and the humid ocean air. I also bought a large roll of heavy duty plastic drop cloth. I went back to the shop and got it all set up. It was clean room quality, or as close enough to it as I was going to get.

The next day I began researching sand blasting materials. Little did I know that high tech cleaning involved either crushed walnut shells or micro rubies. Who would have guessed? However, the more I read online the more it seemed do it yourself sandblasting was pretty problematic. All the sand blasting materials to purchase via the internet were pretty pricing if for no other reason than shipping costs. Eventually, I went back to Home Depot to see what they had. They had no idea. I talked for five different people about sand blasting media and eventually waited around for 20 minutes until their "expert" was free. He directed me to a $5 bag of sand and told me that was what people used, even though the bag said not to use for sandblasting on it. They were no help. I bought the bag and schlepped it back to The Shop.

C and the brothers assessed the situation. R had dug out the sandblast machine for me. C was concerned. I told him about all the research I had done. After conferring with A and R they decided I probably should outsource the sandblasting job just to be safe. I agreed I did not want any of the Brothers put in health jeopardy from flying silicon micro particles from the sand.

Back at the computer researching sandblasting businesses in my area I was trying not to get discouraged. Of course this was going to be more expensive than I expected. Of course The Brothers were going to proceed cautiously. I proceeded forward without complaint since it was my project. I learned about powder coating and while it had an appeal it was too expensive. I tried using the web to find pricing and turn around time information, but despite being the 21st century this was near impossible. Finally I resorted to old fashioned phone calling, but even this was challenging as many businesses had closed or I was dealing with contractors who were out and about.

Finally, I found a place in the neighborhood. They would not quote me a price without seeing the item. I met C at The Shop early one morning before work and we took the frame to the metal working shop. One day turn around and the same price I had been quoted elsewhere. A deal was struck. We left the frame and picked it up the next day.

Now we had a clean frame, a place to store it, and primer and Bondo to repair it.

Phase 1: Research and Design

As I began my process it was clear I was in charge of finance, research, and design. Each month I planned to set aside a few dollars towards my project. I scoured informational pages on building VW trikes. Guys had been doing this for decades and there was a lot of information out there, both through chopper websites and VW aficionado websites. I had a lot of homework to do. I thought C and his brothers might be able to use the spare parts. No, I was told, there was no extra space at The Shop for more vehicles until some other project was finished or a vehicle was sold. There were webpages where guys would build frames for you, but that was thousands of dollars I did not have. Several of them sold instructional manuals on how to build your own, but most of them believed it was a bad plan (because they wanted you to buy one of their's). Solution, buy a frame.

I began with Craigslist and The Samba. One guy in San Diego wouldn't sell me his frame because it was too much for a little girl like me to handle. Geesh! I gave C the contact information and let him work on this old coot. To know avail. Eventually, I found a guy in the desert who was emptying out unfinished projects from his yard. He said it was a '69 VW bug rear end he welded to the front end of a Harley. He said any standard Harley front end would fit it. Deal!

Mid-August I got C to load into my car, because it had working airconditioning, and out we drove to the desert. It was actually hotter in the Valley that day than it was in Lancaster, but either way we were glad to have the AC. The frame was ugly. It definitely needed sandblasting, but no structural damage, just cosmetic patches. $200 and a handshake. Now the project has officially begun.