Revisiting an unfinished prototype – sociable tadpole trike

In 2001, I decided to tinker in the garage with my angle grinder.

Once in awhile, I like to dig through my photo archive labeled “the Graveyard” where I keep photos of unfinished or failed bike and trike concepts made over the years. Sometimes these ideas just fail completely, or they become too complex to make into plans since I try to ensure that anyone with nothing more than a basic welder and a grinder can do the same work I do.

So, I was waiting for some microcontroller code to compile the other day and I want for a photo trip down memory lane and found an old project called “the Sociable Tadpole Trike” and it sparked some new ideas.

I remember building this thing sometime around 2001 or so. I scoured the ‘Net for any examples of a side-by-side (sociable) tadpole trike (two wheels up front) and there was nothing out there at all, so I thought it would be cool to make the first one. Without any forethought, I spent a free Saturday cutting up tubing to make the trike. I don’t think I even measure a single tube, but sometimes that’s how it goes when you are driven by an idea – cut first, measure things later!

I had some leftover machined 20mm tubes that were part of another project and they fit nicely into a 20mm hollow axle hub wheel set that I built the year before (these were eventually used on the Warrior and Viking Trikes). To make the front steering, fashioned a bracket from two pieces of angle iron and then welded the 20mm tubes to another tube that held some brass bushings. A bolt acted as the kingpin. The odd angles shown between the kingpin and axle tube are there to allow for center point steering (this makes the wheels pivot in their center on the road).

My first attempt at center point steering.

This steering system worked out quit well, but I never used it on any of our plans because it requires four machined tubes to be made and unless you have your own lathe, these small jobs cost a lot to get done at a machine shop. But, for this prototype I decided to just use whatever bits I had on hand in order to make the trike functional in the one free day I had to work in the garage. Yeah, back in 2001 I had a garage to work in, so I didn’t have to dodge the weather all of the time!

The prototype trike required machined tubes for the steering system.

The Sociable Tadpole Trike went together in a hurry and actually looked pretty good when it was done. The steering was almost perfect and the frame seemed stable and strong. I even had an independent transmission system rigged up that ran the two cranks to a transaxle that had independent derailleurs for each rider and a main drive system to the rear wheel, but sadly, I did not take any photos of this unit. I thought for sure that this trike would make it to the plans page, but after rigging up some temporary seats the next day, I found an unfixable flaw in this design – elbow room!

My prototype Sociable Tadpole Trike
 

It seems I misjudged how much room two people sitting side-by-side would need, especially with the captain having under seat steering, so the trike would need to be almost 5 feet wide in order to steer properly and not have the rides sitting shoulder to shoulder. I made the trike exactly 4 feet wide, and decided that a 5 foot wide trike would be too wide for any practical use. Eventually, this design was flipped around and made into the Kyoto Cruise Sociable Delta Trike, which was no wider than 4 feet.

But, the point of this musing is that I intend to revisit this concept once again, and have a wild and crazy idea on how to make the trike less than 4 feet wide, have an independent transmission, suspension, and need only simple components. Are you ready for this one? Front wheel drive and rear wheel steering!

Yeah, that’s right! It will have fixed front wheels driven independently like on the Kyoto Cruiser and run a linkage to a rear steered wheel.

Now, normally I would recommend against a rear steered vehicle as they have quirks, but in this case, the width of the trike along with the riders being placed over the front axles would make the trike stable. I wouldn’t use it as a racing trike, that’s for sure, but for a fun sociable trike, I think the rear steering would work just fine, and allow for a nice stable ride with a great turning circle.

Richard Buckminster Fuller, inventor of the Dymaxion

There was an interesting rear steered three wheel car called the Dymaxion invented in the 1930s by Richard Buckminster Fuller and it seemed to be quite maneuverable and stable from the text I was reading. The length and width of the trike seem to make the difference, which would make sense if you think about how a rear steered vehicle would handle.

A short wheelbase rear steered trike would want to oscillate due to momentum of swinging the rear during a turn, which would then cause the pilot to counter steer and create a hard oscillation that could lead to a rollover. Add speed to this equation, and you have a ride that would not be easy to tame. Add a wide track and a longer wheelbase to the vehicle and it should steer more sensibly, allowing the vehicle to make nice tight turns and handle in a controllable manner.

Now, this is just my “guess” on how the thing will actually work, but I have been thinking about making this my next trike project for 2013, since I really miss the aspect of cruising side by side. If this new FWD Sociable Tadpole Trike actually works, it may be the base for a full body, since it would be easy to make one due to the fixed front wheels and the teardrop aerodynamic shape. In fact, the body might look like a mini Dymaxion!

Well, there you have it, a new idea is born and it will involve some things that have not yet been tried, so I am all charged about either making a new plan or adding to my folder called “the Bike Graveyard”.

~ Brad

Apples, Sparks and Skitters

Summer is definitely a lot better than winter! Let’s face it, when it’s -30C out or even -10C, you cannot work in an unheated space. I have tried this in the past, and even if you can keep your hands warm somehow, the welder won’t run right, causing sticking and burn-throughs nonstop.

There are good and bad things about summer as well, but for the most part summer beats winter any day. Along the pathway down the hill to my building shack are several apple trees and Saskatoon bushes, and I find myself living on the fruit for days on end when I work on a new project. A few gallons of ice water and the apples are usually enough fuel to keep me going for eight hours or more.

Thanks to a lot of rainfall lately, the Saskatoon berries are almost ready to pick, the raspberries are coming along and the apples are about half way there. I look forward to “living off the land” once the berries are ripe, but will probably have to deal with that bear again. Oh well, I have a plan this year, and it involves some “MacGyver-like” contraptions.

Of course, summer does bring it’s annoyances as well and yesterday they almost drove me completely mad. Yeah, you already know what I am going to say…black flies, ticks and mosquitoes! It was raining yesterday afternoon and then the temperature went right up to 30C, so I took the opportunity to head down the hill and see if I could get the Transporter Cargo Bike together for this morning’s blog, but the mosquitoes were so bad that I had to run like a coward back into the house.

Since there is a 60 foot difference in height between the old shack I work in and our house, the climate is completely different down there much of the time. Up on the hill, it is always dry and breezy, but down the hill, it can seem twice as hot, muggy and often no breeze at all. Add to that the fact that my shack has no doors and you have mosquito hell sometimes.

I did manage to get the wheels and chain on the bike, but after dropping the bike twice to swat humming bird sized mosquitoes off my neck, I gave up in frustration. The grass was too long, the place was humid like the rain forest and water was leaking through the roof, so it just wasn’t a productive afternoon. I am really looking forward to getting the new bike out for a test run, so I will see what the weather has in store for me today.

So far, the Transporter Cargo Bike came together very well and only needs to have the brake and shifter cables installed to be usable. I also have to come up with some kind of latch to hold the kickstand up, but have a plan on the drawing board for that. The other tricky bits will be the rear shifter and brake cables, since they need to be more than twice as long as those on a regular bike. I do have some long throttle cable that was purchased off a roll from a motorcycle shop, so I think that will do the trick.

Well, that’s it for this morning; not too much to report on the new bike. If it dries out a bit today, I may get the chance to add the cables and get a few action photos of the completed bike for tomorrow’s blog. Hey, I wonder if I could weld and grind with a mosquito net over my face.

~ Brad

Painting under the stars

Yesterday I managed to get a full day in on the latest project “the Transporter Cargo Bike”. It was a hot one, but now that I have power running down to the old shack, I was able to stay somewhat cool by aiming a huge fan at myself as I welded and grinded away on the almost completed frame. My goal was to complete all of the welding and have the frame painted before the end of the day, but with all of those round tube trusses to weld and the fact that I had not yet figured out the kickstand, I knew it would be a late one tonight.

Since the Transporter was really turning out nicely, I decided to go all the way and add a front disc brake. Actually, this worked out well for the plan because I could now show the steps needed to remove the brake studs from the front fork and install them at the rear and then show how to make a disc brake mount for a front fork that had none. Since most of the stopping power is needed at the front of a bike, the disc option was a good one for a cargo bike that may see loads topping the few hundred pounds mark.

The cardboard template method of making a front disc brake mount went well, and was easy to do thanks to the “weld it in place” method of aligning the brake hardware. I will probably make this into a separate mini tutorial for the main page, since disc brake hardware is becoming very common and inexpensive these days, and is fairly easy to install.

Now, I was faced with how to design the kickstand. A good kickstand is a key feature on a cargo bike; it has to hold the bike stable while the heavy loads are moved on and off the platform. Obviously, a flimsy side kickstand would be pretty useless, so I worked out a stand that would raise the front end slightly off the ground and level the bike on both sides for maximum stability. This type of kickstand is called a “center stand”, and turns the bike into a trike, with three points hitting the ground (two stand legs and the rear wheel). After some testing, the stand proved to work very well and was made out of nothing more than some tubing and bits of flat bar.

When I finally finished all the welding and did a little sanding on the rough spots, the sun was already setting. I decided to paint the bike under the moonlight and brave the mosquitoes that were now coming at me in large waves.

I decided to use brush on paint this time since this bike would be taking a beating and living outdoors mostly. Instead of a perfect paint finish, I opted for a slathered on thick coat that would be easy to retouch as the bike was used like a piece of farm equipment. Under the dim light of the moon, I slopped on the paint as thick as peanut butter, painting the bugs right in as they landed on the tacky paint! I could barely see what I was doing, so I figured the paintjob would be less than pretty in the morning, but yellow is somewhat forgiving and the goal was durable paint, not a showroom finish.

Next morning, I took the frame out for inspectio, and wadda-ya-now, the yellow paintjob wasn’t all that bad! There were a few spots needing a bit of retouching and some runs near the joints, but at a distance of 6 feet away, it looked as good as a spray on paintjob. I may use brush on paint a lot more in the future since it requires no primer, and costs only $10for a can that would paint 3 bikes.

The only drawback to the department store rust paint is the selection of colors: black, white, grey, red, green, blue, orange and yellow. Knowing that I can make any color imaginable by mixing red green and blue, I have a cunning plan for my next brush paint job – mix ’em and see! By using the color picker in Photoshop to get the RGB values, I “should” be able to concoct a similar color by converting the decimal value to a volumetric mixing value.

Well, that completes the first official plan of 2013, so if the weather holds out today I may get the chance to assemble the Transporter Cargo Bike and show it off in tomorrow’s blog entry. I am looking forward to hauling that old freezer out of the bush and then loading a few hundred pounds of firewood onto the cargo bed to make some fun videos of the bike in action. Type y’all tomorrow.

~ Brad

Update – Head tubes and bottom brackets for your bike projects

We are updating the AtomicZombie store to begin accepting pre-orders very soon. Because we do all of this in our spare time, we have to direct our attention to our “real” jobs and thank you for your patience.

AtomicZombie is a two-person operation – Brad and Kat – and there are only so many hours in day to get things done. We’re doing our best for our AZ family and aim to keep expanding our worldwide community.

We appreciate your understanding and continued support.

Yes, head tubes and bottom brackets are being made as I type this. We expect begin shipping orders in late April or early May.

However, we will be accepting pre-orders within a week. So, stay tuned to the forum, AZ newsletters, blogs and social network sites like Facebook for announcements.

Bike builders news November 12

 

In this issue:

 Feature article by RadicalBrad of AtomicZombie.com:
Building a Velomobile – Part 1

Do you want to save money and leave the gas guzzler at home more often or for good? Do you want to learn how to build an eco efficient transportation alternative? Atomic Zombie will show you how!

This issue features our newest project, an electric assist velo for a delta trike similar to the Aurora Delta Trike. The build blog will include videos later this month. The velo build will be a regular feature in our newsletter and blogs. The brainstorming sessions have begun. Read all about it in this week’s issue.

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Hub flanges and axle adapters for your bike projects
Bike builders community chat
Bike builders gallery – new additions: recumbents, trikes, choppers, tall bikes, kids’ bikes, cargo bikes & more

This and archived newsletters are here.

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Thanks for your feedback, and keep those suggestions coming.

See you in the Builders Forum.