In the forum of the website ratrodbikes.com every year there is a big bike building contest going on, a so called BuildOff. It usually runs from may 1st until beginning of september. Besides honour and respect from other builders from all around the globe and a homemade trophy from last years winners, there is no money to win. The judges at the end are all the members of the forum.

This is my entry from last years BuildOff: The "Campground Buggy Trike". This bike ended up on 7th place out of 41 finishers and won a special award. That's my best result so far after participating 5 and finishing 4 times.

It all started as a beat up bare bones NSU ladies frame with matching fork, probably from the late 50ties, a negleted baby buggy from the 60ties and a decomissioned therapy trike. The plan was to marry these three into a trike with a trunk.

After all I ended up with a very fun and practical ride! So regarding the contest: no price needed, I got mine already! (But I would appreciate your vote anyway). See also the video in the last step ;-)

Supplies

Parts

frame of a 50ties ladies bike (NSU)
baby buggy of unknown origin, probably from the 60ties
therapy trike (Haverich, about ten years old, still produced)
rear triangles from another frame, that had already been transformed into a stool before
vintage 60ties car rear lights (from Opel Rekord P2)
various (vintage and new) bike parts
various electrical parts (switches, cables, battery, ....)
Ikea parts (I never throw Ikea hardware away, never!)
grey cardboard
plywood
tape rolls

Tools

basic set of bike tools
basic woodworking tools
corrugated cardboard
soldering station

Paint

set of quality cans from Molotow
tape
tomato paste ;-) (curious? got to step 11)

Step 1: Mock-Ups, Sketches and a Basic Plan

First I had a good look at all my parts and pieced a basic mockup of the frame together and thought about where and how to place the buggy as a trunk.

So I had to take apart the therapy bike and mount the rear axle to the ladies frame. This gave me a first idea how to continue from there on and come up with ideas an a basic plan to work from.

The mockup happend almost a year before the start of the actual contest (which is all covered by the rules: you are allowed to do mockups, just don't start building before 1st of may)

Based on this mockup is my first crude sketch and later in the build I even made a rough 3D version with SketchUp.

Step 2: The Basic Trike

First I had to put together the basic trike and make it work. So I went at it and took apart the trike. The ladies frame was already releaved of all the unnecessary parts when I bought it.

Adding the trike axle to the frame was really easy, as the rear end of the ladies frame was of similar form as the trike. Both had horizontal dropouts.

I added a stem and an apehanger handlebar, a frontlight I had on stock and grips (needed to extend the handlebar length for this, see pictures). I also added front brakes and a chain. All parts came out of my parts boxes, saved from older builds.

With the trike axle on it, there was no more need for the stand so I took it off and while at it I also exchanged the pedals to some black ones I found in one of my boxes, as the original ones were toast.

As the whole frame sits much lower due to the 20" rear wheels (compared to the original 28" the frame was made for), the pedals now are very close to the ground. Clearance is around 1-2 cm. So on uneven ground I hit the flor with the pedals quite often. Changing the crank was no option, as these type of bottom bracket crank combination (Glockentretlager) is really hard to take out and when doing it, the risk of frame damage is very high. So after a while I decided to swap pedals with another bike. With the sturdy red BMX pedals that are on now (last picture) touchdowns are no problem anymore...

So the trike was ridable now and ready for further additions....

Step 3: Base for the Trunk

I put a lot of thougth into how to construct a solid base for the trunk without welding. What I came up with was using parts of another rear triangle and fix them to the dropouts of the trike. first I mounted them to the outside, but that didn't work due to clearance issues with the trike axle. So I swapped them to the inside. That worked much better.

Then I slowly started bending the remnants of the seat and chainstays horizontally. With some brute force a heavy old vise and an old fork as lever extension I finally got a halway levelled platform for the trunk through som trail and error.

Step 4: CAD - Cardboard Aided Design

With the platform ready, it was time to make some design decisions. The easyest way for me to do this is through CAD (as in Cardboard Aided Design). It's hands on, analog and cheap.

First I transferred the side panel to packaging paper and from there onto cardboard. this cardboard side piece got mounted on some slats that could rest on the platform from the last step.

Like this I could move around the "trunk" to find a good position for it that flowed well with the rest of the bike. As you can see on the picture with me sitting on the bike, I also needed to make room for my heels while pedaling.

It became pretty clear at this stage, that the buggy had to be rebuilt. With that in mind, I could also decide of the final width of the trunk as the original buggy was to narrow to fill the space inbetween the rear wheels to my satisfaction.

To make this rebuild as easy as possible, I then built a full scale mockup out of cardboard. I decided to run the front wall along the seatstays and let the sidepanels protrude outside of the pedaling area.

Step 5: Dismanteling the Buggy and Improving the CAD-design

Very carefully I took apart the buggy. It was mostly built out of grey cardboard, mounted on a wooden frame. For now I kept all the parts for future reference.

To find out if the cardboard mockup had the right size I fixed the original sidepanels to it with some clamps and string. It was tight, but enough clearance and I really liked the look of it.

Step 6: (Re-)Building the Buggy-trunk

The rebuild of the trunk started of with some precut 6 and 8mm plywood and grey 2 mm cardboard.

First I made the new sidepanels (6 mm). I'll later mount the original panesls onto these so they had to fit as perfect as possible.

Next was to join the sidepanels with bottom and front. for this I used flat dowels to be as precise as possible. the panels were than glued together and also nailed from the outside. Better be safe than sorry...

For the curved side I added several strips of ply to support the bended area. As preparation for the cardboard I also angled the rear edge of the underside of the bottom panel with a file.

Next was fixing two layers of cardboard to the curved end of the buggy. The first layer was glue onto the edges of the ply panels and stapled down starting from the top, ending with some exccess cardboard on the bottom edge. After that I added a second layer. This layer was glued on on the full surface and also stapled down on the edges. To let it dry I tyed some cheap corrugated cardboard ont the curve with some string. Like this I let it cure for a day, to be sure that all the glue had really dryed.

With the glue dry, I smoothed the lower edge, so that the curve flowed almost seamless into the floorboard.

After some testfitting I started sanding down the green paint from the sidepanels. With that done, I glued and nailed the original sidepanels to the new trunk.

With strips of ply I then finished up the rear top edge of the trunk and filled the remaining gaps in the front.

Finally I walled off the curved front and back section with some thin ply to create room for the electronics.

Step 7: Marrying the Trunk to the Chassis - Horns and Sirene

Next I placed the (car) horns and a sirene I purchased on a flea market a long time ago behind the front wall. Now the trunk was ready to get married with its chassis. First I fixed it with some standard hardware to it to determine the right spots for the drive-in nuts. As the front of the chassis was a bit to low, I added some spacers I had left from a broken IKEA stool I had taken apart before throwing it away.

At this point I started to use the bike as a daily ride on the campground. Like this I could make shure that everything worked, before I later painted it.

Step 8: Taillights

After a long waiting time filled with hundreds of searches, all of a sudden this magnificent taillights of an old Opel Rekord P2 magically appeared a well known auction site. I could get them for a fair price and as soon as I had them, I started searching for options to mount them. I decided that arranging them in a classic horizontal line suits the trunk best.

The only problem was, how to mount something flat on a curved surface. Here a very helpfull fellow bike builder stepped in an pointed me to the technique called frenching. I quickly realized, that this was the solution to my mounting problem and started looking for fitting cardboard tubes. I found out that standard tape rolls had the exact size necessary...

My largest hole drill was a bit to small, but some grinding took care of the missing millimeters. From some 4 mm ply I made a baseplate to mount the the lights to and the glued the taperolls and baseplate in to prepped holes of the trunk. I place the rolls just deep enough, that the tips of the lights still show a bit, when lookes at from the side.

With the rolls glued in and the glue dryed, I cut off, what was to long and mounted the lights.

Step 9: Paint Job (Trunk)

For the paint I searched for inspiration on many classic cars sites. Basically I wanted to have a two-tone paint job. After looking at many pictures I decide on a combination of black, white and ruby red. The reason behind this is the fact, that one of my previous bike builds an it's trailer where painted in the same ruby red and the frame was already black and I wanted to keep it that way, only with subtle changes.

The other important decision was, that I wanted to make look old and used, so I studied a lot of pictures and videos about fauxtina paint-jobs.

To decide on how to paint I used a image editor on the PC to create various combinations of red, black and white and compare them. Finally #11 made the cut.

Before sanding the whole trunk, I treated all the little holes from the nails and several older dents with filler and roughly sanded it when it was dry. After fine sanding the trunk I clear primered it. Another sanding session and a second coat of clear primer then. Then I sprayed the inside white and taped and covered it all up when it was dry.

On the outside I finally did another fine (wet) sanding and I could lay down several coats of black. This is my base coat that tells me when I have to stop sanding when working on the fauxtina later.

Next was a thick layer of rust. I used a set ranging from brown to orange and yellow. I tryed to get it as irregular as possible, even spraying with two cans at the same time. It's sometimes really usefull to train the weaker hand to do the same as the stronger one... ;-)

Next was the white section, that got taped of as soon it was dry, to paint the red and finally the black swosh got painted.

In it's shiny intermediate stage the trike quickly got nicknamed as Clown-Trike. To avoid further joking I quickly went at it with some fine wet sanding paper to sand away the shine and to let the rust and black come through.

Step 10: Wiring

With the paint job all done, I finally could focus on the eletronics. The plan was to make front and taillights fully 12V battery powered. And there where also horns and sirene and I wanted to incorporate indicators into the taillights.

Power source is a 12V motorbike battery.

First step was to build a base for the battery to sit on. Then I routed the cables for the taillights trough the side panels (this took a lot of trial and error and even more patience) and connected the taillights.

The frontlight was already electrified and converted to LED in a previous project. When I powered it up the LED decide to die so a transferred it to halogene. As a little special I added two red LED strips I had left as underfloor lights.

I added several switches and buttons to the front plate: a main switch in the center, two push buttons for horns and sirene on the left.

Main lights and indicators relais (the two little orange boxes) are operated from the handlebar through two vintage NOS motorbike control switches.

When all was connected and operational I added a fuse and a little control panel to see the status of the battery and cleaned up all the wiring.

To be able to access the battery quickly I added some camper hardware to the top panel of the front compartment.

Step 11: Final Touches

The original frame and fork where showing years of use and I wanted to keep that vibe, but in the same time I wanted to optically tie together the frame and trunk with some little design touches.

First I took care of fork an frame. When I started, the fork was decorated with strips of white tape. This had to comme of first. Than I taped of some kind of swoshes on fork and frame, inspired by the swoshes on the trunk. No comes the secret ingredient into play to create/keep the effect of the beat up paint: tomato paste (others use mustard, but that was, what I had on hand and both work the same way).

After taping up the desired design, I coverd all the parts that had no colour or showed marks of use with small dabs of paste and then spryed white over it. When the paint has dryed, wo wipe off the paste and take of the tape and voilà, it looks like it has always been there...

Also the headbadge needed some attention. In it's earlier life someone had just painted black over everything, including the headbadge. First I brushed and scraped of all the black paint. Then I carefully filled the lower parts with ruby red. When the paint had dried, I took some fine grit sandpaper and carefully sanded away the excess paint on the upper parts.

In one of my many parts boxes, I still had a alternative chainguard from my NSU. Already painted in the right colour, just a bit to shiny. I treated it with some light brown and black overspray and mounted it with some makeshift hardware.

Earlier on I had ordered some nice stickers for the front wall of the trunk. And a built not bought for the rear. I also added a little cover for the two push buttons (drawer pull).

The front wheel got a new whitewall tyre and winged nuts and the modern grips got replaced by some mor fitting vintage NOS grips.

I don't remember when, but at one point in the build, I realized that haveing a standard break lever is not very practical, as the trike tends to roll off, so I installed the break lever from the thrapy bike that had the option to lock it and so keeping the trike parked.

Step 12: Fotoshooting and Videos

As this bike was built for a contest it was necessary to take some nice pictures of it. So I took my trike on a spin around the campground through the ouskirts of Berlin-Kladow

Step 13: Final Words and Possible Additions

The 12 V battery I used proved to be to weak, so in the long term I'll need a stronger one and I really have to exchange all the standard and halogene bulbs to LEDs

The trike as it sits now is single speed. Maybe I will build in a 3-geared hub at one point, but that would need some specially machined parts that I cannot afford to let them ade right now.

I already started building a cover, also made from cardboard. Maybe I will finish it at some time, we will see.

But before all this, I will need to replace the left rear axle. The whole system ist built to be taken apart and at some time one screw must have become loose therefor the left axle started to wander to the outside. When it reached it's weakest point, it snapped and left me stranded in a park. I had to push the trike about 2 km back home, balancing it on its remaining two wheels. Lucky me it is a standard part of the company manufactoring the therapy bike, but it cost almost as much as I spent for the complete trike when I bought it from its previous owner... :-(

At the moment the trike is parked in a old trailer next to my caravan and waits to be reawoken. And it will happen pretty soon, as this bike is so much fun to ride, it really begs to be moved.

The fun in this project was, that it involved a lot of different skillsets, as it was not only about building a bike, I had to do woodworking an papermache, but also electronics. I learned a lot of new things on the way (frenching...), which will come in handy in further projects. And after all it helped me clear my mind from all the covid and teaching related stuff, especially over the summer break and allowed me to start into the new school year with a fresh mind!