The HammerHead Winter Trike

hammerhead winter trike
Hammerhead winter trike

 

 

This simple DIY project is designed to inspire you to build a bike to conquer a typical winter climate with snow, ice and slush. The Hammerhead is a two-headed monster that eats snow and ice for breakfast, and has no fear of Old Man Winter or his frozen wrath.

I designed this two headed bike to give myself a way of staying in shape during the winter months. I used to take my fancy, overpriced mountain bike out for winter rides, but soon realized that it wasn’t suitable in deep snow or around icy corners, and the bike was taking a lot of abuse every time I bit the dust (snow).

Obviously, a three-wheeled bike was necessary to maintain balance, so I rebuilt one of those old-style trikes (the kind with two wheels and a big basket in back) and tried to make it as light as possible by removing all parts that weren’t needed, and then added some knobby tires for better traction. The results were very disappointing; not only was this bike as heavy as a tank, but it also had no traction at all. Because that style of trike only drives one of the rear wheels, it mainly just spun around on most surfaces except bare pavement. Adding a differential (a gear system to spin both wheels and transfer power between them) was just too complicated and would add even more weight, so I decided to scrap this type of approach.

My new plan was to have two front wheels for stability and one rear driving wheel for traction. The two wheels up front (tadpole style) design is popular on low-slung recumbent trikes, making them very fast and comfortable, but it is not a suitable design for a winter bike for several reasons.

First, you don’t want to be slung two inches from the slushy ground while winter riding because you will get very wet from wheel spray.

Second, most people driving motorized vehicles will not normally expect to see bicycles in the winter months, so you want to be as visible as possible. A low recumbent trike is not very visible to drivers of motorized vehicles.

Third, is road salt. If you live in a community that routinely uses salt on roads and sidewalks, then this is a problem because salt will corrode metal. Why spend so much and money on something that will require many custom-made parts, and will end up rusted at the end of the year?

Hammerhead is not only as high as a regular bike, but it needs only regular bike parts and a little welding here and there. The design uses a regular mountain bike with two head tubes welded on each side of the frame in order to support two sets of front forks and wheels. Both wheels steer at the same time just like skis on a snow machine. In fact, the steering linkage that I scavenged is from a snow machine!

The trike is called Hammerhead because I thought the finished frame looked something like a hammerhead shark. You see it too, right?

Parts You Will Need

Now that you have a plan and a desire to conquer winter, let’s start by gathering some parts. As shown in Figure 1, you will need a complete mountain bike (stripped down to the frame), two front wheels, two head tubes (ground clean) and a matching pair of front forks. The critical requirement here is that both head tubes, forks, and front wheels be identical or very close in size. Even the tires should be the same, as any mismatch will cause the final bike to be uneven and wobbly.

bicycle parts for the winter trike
Figure 1 — Gathering parts for the Hammerhead trike.

 

 

The first step is to create the two head tube extensions. Each head tube is welded to a pair of 12-inch lengths of one inch diameter thin walled electrical conduit, or similar bicycle frame tubing. These two tubes are then welded to each side of the original head tube on the frame. Both tubes are welded at exactly 90 degrees to the head tube, as shown at the top in Figure 2.

If the original head tube is not as tall as the two new head tubes, position the new extension tubes so that they are able to mate to the original head tube. To make a good weldable joint, fishmouth the ends of the tubing to conform to the round edge of the head tube as shown in the lower part of Figure 2.

Weld carefully, tack welding only at first to ensure that the two tubes end up at 90 degrees to the head tube. Any error here will result in a front wheel misalignment, so check the angles with a 90 degree square as you work. Look ahead to see how the extension tubes will place the two new head tubes at the same angle as the original head tube and at 90 degrees to the frame tubing.

hammerhead trike has two head tubes
Figure 2 — Creating the two head tube extensions.

 

 

When you have both head tubes welded to their two 12-inch tubes, it’s time to weld them to the original head tube on the donor frame.

As shown in Figure 3, the extension tubes are welded to the original head tube so that all head tubes are at the same angle and so that the extension tubes are at 90 degrees to the frame tubing. You want each head tube to end up at the exact same angle as the middle head tube so that the caster angle remains the same as it was on the original bike. If you imagine two identical bikes standing side by side, then you can picture what we want here.
At this point, just make a few good tack welds around the joint to secure all of the pars together. A final alignment check will be made by installing the forks and front wheels to compare them with each other.

align the head tubes
Figure 3 — Weld the head tubes so that all three align.

 

 

To ensure that the two head tubes are aligned with each other, put the bearings, rings, and forks on both sides and then install the two front wheels. Remember that both front wheels must be the same diameter, which is why both tires should be the same type. When you have both wheels installed, stand up the bike and place both forks in the straight ahead position for a visual inspection. With the parts only tack welded, you can probably make slight alignment adjustments by tapping with a mallet.

Once you are certain that both head tubes are aligned, weld around all of the joints, following the same order on both sides so that any distortions happen equally.

check fork and wheel alignment
Figure 4 — Checking alignment using the front forks and wheels.

 

 

To make this frame structurally sound, a set of trusses will be added to the front in order to triangulate the frame. The frame is somewhat rigid as it sits, but any hard force to either front wheel could bend the frame at the joint between the head tube and the new extension tubing.

With some simple trussing, we form a triangle on each side, making the frame extremely strong. Any tube with a diameter between half an inch and 1 inch will do for the trussing. I found some old lawn furniture with 3/4 inch tubing and cut a few pieces to make the trusses.

These trusses are welded from the top of each head tube to somewhere near the middle of the top tube on the main frame. The trussing should be installed a few inches head of where your knee will be when you are pedaling the bike. To find this spot, put on a crank arm and set the seat to your height, then mark it on the frame while you pedal. The main goal is to make sure your knee does not hit the tube.

truss tubing increases frame strength
Figure 5 — The truss tubing makes the frame very strong.

 

 

Stay tuned for more on this project. Part 2 coming soon.

 

AtomicZombie bike plans
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Human powered helicopter

It was great to hear that the Sikorsky challenge has finally been conquered. This challenge was put forward by the Sikorsky Aircraft Corporation way back in 1980 offering half a million smackers to anyone who could create a human only powered craft that would hover stationary in a space of no more than 30 feet x 30 feet for a minimum of 60 seconds at an altitude of at least 10 feet. Anyone who knows something about air flight will tell you that this a huge challenge, pushing the absolute boundaries of what is considered possible.

But, in July a Canadian team (Aerovelo) at the University of Toronto comprised of students, staff, volunteers and professionals claimed the prize with their human powered copter called “Atlas”.

The amount of engineering and trial and error that went into designing and building the ‘copter is daunting. Here are some impressive specs of the machine:

Rotor Radius: 10.2m (33.5ft)
Maximum Dimension: 46.4m (154ft)
Height: 3.7m (12.1ft)
Overall Weight: 55Kg (121.4lb)

Can you imagine what it takes to spin up a four 33 foot blades and lift yourself plus the 120 pound machine into the air, at the same time controlling the flight in three dimensions? WOW is all I can say!

Atlas ready for the winning flight

 

When you see the entire copter sitting there on the ground, you can really appreciate the engineering that went into making such a huge machine only weighing 120 pounds. The framework is made of composite rods and wire, so it is lightweight and just strong enough for the task at hand. The team went through many design changes over a year as they worked out the limits of the framework, snapping tubes and breaking many support wires along the way.

The Atlas transmission system

 

Everything about this craft is cool! Here is a shot of the transmission system which includes a high RPM fixed gear rear wheel that acts as a dampening system to smooth out the pilot’s pedaling efforts. This makes sense because there is little power at top dead center during a crank revolution that would lead to slowing of the rotors and would probably cause huge oscillations in the frame and massive power loss. This flywheel keeps the power output constant without really storing any energy and that would break the rules of the contest. On the left side of the crank, there is a set of pulleys and guide idlers that transfer power via cable to the rotors. Cable drive is necessary because a chain of that length would weigh too much. Check out the huge chainring; there must be 80 teeth on the beast!

The cockpit?

 

The pilot sits atop a carbon fibre road bike frame that is suspended in the main frame by wires. Craft control is accomplished by rods attached to what used to be the brake levers. I have not seen much detail on the control system, but would I imagine that it works by simply flexing the frame so that the pilot can change the angle of the rotors slightly to fine tune position while in flight. According to the rules, they have to stay within a 30 foot by 30 foot space for one minute.

One of the rotor flywheels

 

Every part of the craft is made using the lightest possible materials. This required some seriously detailed work from the team. The picture above is one of the four rotors, a huge spoked wheel made of composite materials and wire for spokes. If you think that lacing a 36 hole bicycle rim is a chore, just imagine making this wheel!

So, a big AtomicZombie congrats to Team Aerovelo for rising to the challenge and pressing forward after many broken frames, snapped wires and crash test flights! A lot more info on Team Aerovelo’s Atlas craft can be found on their website here: www.aerovelo.com

A unique highway lowracer

A big wheel forkless lowracer

 

Even though my bike building has come to a bit of a halt this year, that doesn’t mean I’m not coming up with new ideas on a daily basis.  A few times a day, I like to find a quiet place to relax with a notebook and sketch up new project ideas. I have really missed my Marauder. I think it may be time to make another long wheelbase lowracer so I can get out once in awhile to feel that burn as I push both machine and engine to the limits. The terrain out here is not the same as the city, so my lowracer will need to have suspension to take me down the gravel road out to the highway. There isn’t much traffic on the paved highway around here and the ride would certainly be challenging thanks to hills and tight corners.

Another option is to transport it to a nice stretch of country road about 15 minutes from here where there is very little traffic and fairly smooth straight terrain. There are many cyclists using this stretch. I can just see myself eating roadies up once again as I slip under the wind and pass them one by one!

 

Some forkless bike examples

 

This time though, I want a very unique lowracer that has 700cc or 26 inch wheels on the front and back, a rear suspension, over seat steering, and no front forks. Yep, you read that right, no front forks! I have two designs for a forkless bike: one with a hinged triangle and the other with a wrap around frame that allows the front wheel to pivot much like the front wheels of a quad or tadpole trike.

Having no fork over the front wheel would mean that a larger wheel could be used without obstructing the pilot’s view. This will also smooth out the ride, so it would be a decent chassis for an aerodynamic fairing, allowing the rear suspension and long frame take up the bumps. Suspension is a must on a faired lowracer since these things can easily reach automobile speeds, making the smallest bump feel like a pothole. The forkless design and long wheelbase configuration also keep the front of the fairing low so that you can see the road ahead rather than having to peer around the body. This type of streamliner would not be all that great for pack racing on a track, but out on the open road, it would be a real blast!

 

A crazy pivot fork bike

 

The easiest forkless design is shown in my sketch and in these cool examples, where the hub pivots on a kingpin held in place by a single tube that wraps around the wheel, leaving space for the turn. I would run a connecting rod up to a control arm just behind the front wheel and then use dual cable steering to get around the curved tube so that there would be less flex in the system and tighter side tolerances for a fitting into a full fairing.

My other version involves a hinged triangle with the pivot very low behind the wheel to keep the tiller effect minimal. I have tried this in the past on this crazy ride called “Tour De Hell”, but the result was a bike that had serious bad attitude and took a lot of practice to ride smoothly.

Of course, having a short wheelbase and a huge amount of tiller, this bike steered like a front end loader, swinging from side to side and causing serious steering feedback. I think this system would work out on a long wheelbase recumbent if the pivot had more caster and was placed much lower to get it closer to the axle. I am not sure if I will actually try the pivot fork design since the other method would defiantly work as expected.

Perhaps this winter I may cut some tubing and lay out my new forkless highway lowracer. I always wanted to build a long wheelbase lowracer and then go all the way on a fiberglass fairing so I can get out and push the limits of what is considered possible under human power. I certainly won’t be heading to Battle Mountain to race with the big boys of speed, but I would certainly have fun smoking past road bikes doing 50 MPH on a faired lowracer down our country roads!

~ Brad

New Plan Online – The Transporter Cargo Bike

The Transporter Upright Cargo Bike

 

Well, it’s finally online! The Transporter Upright Cargo Bike is the latest addition to the AZ plans page and is ready for download. It has been a real battle trying to find a few hours between the rain to get the bike photographed, but the weekend played nice for an entire day. I had fun moving some cargo around the yard and down our windy, hilly dirt roads and everything worked perfectly.

This plan takes a typical department store mountain bike or road bike and converts it into a rear loading cargo bike, leaving the front section of the bike in its original form. By keeping the part bike mostly unmodified at the front, the ride and stance is much the same as any bicycle, so you can head out into traffic and maintain eye level with those gas guzzlers.

A typical yard sale mountain bike

 

This plan is highly adaptable to your needs, and includes a rugged frame that can carry many different types of cargo carrying systems. The Transporter can be made to practically any wheelbase and the entire plan only requires standard bicycle components and a few lengths of round or square tubing, so it will be an inexpensive and straightforward build. I opted for a flatbed cargo top since I intend to move some large items around such as firewood and potted plants.

Testing the brakes down our hill

 

I loaded some heavy cargo and drove the bike down the steep hill up to our driveway for a brake test. Even using only the front disc brake seemed to offer adequate stopping power, and the handling was good. The only learning curve was getting used to the wide turning circle of a bike with an 8 foot wheel base. I did manage to get it turned around in the width of our narrow dirt road, but did use the entire road to do so. For typical navigation, the bike handles just like a regular cycle.

Blending in with the wildflowers

 

Our field is just bursting with color these days thanks to the rainforest-like climate over the last few months. Normally, the wildflowers bloom in shifts of yellow, white and then purple, but this year they are all here at the same time. I rolled the Transporter over to the edge of the yard and got some great shots of the bike contrasting against the rolling blue and white sky and the matching yellow in the field. I think photographing a bike is almost as fun as riding it, and I enjoy trying out different backgrounds to set the mood of the shot.

Well, there you have it, another plan completed. We are now turning our focus towards a set of highly detailed welding, grinding and bike hacking tutorials which will be part of our tutorials page and offered for sale as a complete DVD as well. I should be able to do most of the filming under the non-leaky section of the old trailer, so the rain will not get in the way this time.

~ Brad

Random thoughts, more rain!

Managed to snap a pic in between storms.

 

It’s official; we now live in the rain forest! And, when it’s not raining, the humidity hovers between 70 and 80 percent, so it might as well be. Oh well, here I am complaining about the rain when three months ago I was up to my waistline in snow. I guess that spring and fall really are the only good seasons for an outdoor bike hacker like me.

I did manage to get an hour on the Transporter Cargo Bike and added the cables, levers, and shifters. The first test run went well minus the fact that I had almost no air on the front tire. To complete the plan, I still have to get some photos and video of the bike being loaded with cargo, so it will be a game of waiting for the weather to cooperate.

Wow, a day that might not rain!

 

This week’s forecast is pretty much the same as the last two months with 40 to 60 percent chance of showers, which really means spitting rain every hour followed by intense rain for a few minutes and then 70 percent humidity until the next wave of rain. I don’t ever remember this much rain, and I am seeing plant life that looks like it belongs in the Amazon jungle around here.

New welding and grinding tutorials coming

 

In an effort to do something useful this year, we have decided to start making some highly detailed welding and grinding tutorials to replace the old ones on our website. These will be step-by-step video and photo tutorials from the very beginning that will show a noob what kind of welder and gear he or she might need, right up to controlling distortion. Since bike building seems nearly impossible out here this year, I plan to retro fit the non-leaky side of my shack with some backing boards and turn it into a video studio to make the new tutorials.

I will be purchasing a MIG welder as well for the tutorials since many are using one and will go through the process of both arc welding and MIG welding in great detail. Grinding tutorials will be the same in depth video and photo tutorials with hundreds of images lots of example videos, and text that explains everything one would ever need to know in order to jump head first into this great hobby.

A robot project from 2001

 

I like to dig through my old photo archives when I am doing my morning blog. Here is a real retro photo of one of my first large robot projects. If you can drag your gaze away from my super cool sideburns for a second, then you will see that I am riding on the robot, with an RF controller in my hand during a test run of the differentially steered transmission system. This robot was quite unstable and dangerous since it could reach speeds of 20 miles per hour and then flop over face first when something glitched in the motor drive processor!

But, the robot was fun to operate. I would sit indoors looking at a video link being transmitted from the head mounted camera and navigate (carefully) around the block, interacting with stunned bystanders using a text to speech processor that made the robot talk. I do miss building these things. Once I have an indoor workspace again, I have plans to build a 4×4 autonomous robot that will patrol our yard and keep that dumb bear off the property.

Well, I am going to head our and face the rainforest now. I have to find a way to cut the lawn in between drizzle as it is now knee high in most areas. Talk at ya later.

~ Brad

Paper, Proto, Plan, Precipitation!

A tandem tadpole trike sketch

I was really hoping to have the Transporter Cargo Bike ready to show off for this morning’s blog, so far this year has turned our area into a rain forest. Sure, it’s great for the garden and berry trees, but not great for getting any welding or building time in because my shack has no doors or windows and leaks when it rains. Add to that the 2 foot tall grass and I am starting to wonder if perhaps winter would be more productive after all! OK, enough complaining I will save that for the end of the blog!

While searching for something else to blog about, I thought of what it takes to turn an idea into a working project. I divide the process into three steps: paper, prototype and then plan. Most of the time, an idea never leaves the paper stage. I currently have 43 full spiral ringed notebooks of bike ideas that I have collected from over the last five years. Sadly, I never kept notebooks before that time, so a lot of cool and crazy ideas ended up in the recycle bin.

I usually start with a few pages of rough sketching just to get my head around the basic idea and how it might look.  It takes only a few minutes to sketch up a bike. The sketches offer a decent view of many of the difficulties in designing a bike or trike such as chain line, seating position and steering. I can usually determine if an idea is viable within a few pages worth of sketching, and by the 10th drawing often the bike or trike is radically different than the original idea. This tandem tadpole trike sketch seemed workable, so it was one of the few drawings from several thousand that moved to stage two – prototype.

The Viking Tandem Trike

All of the AZ plans go through a prototype stage so that ideas can be tested in the real world and then either modified or scrapped. Having a rough prototype means I can beat the hell out of the vehicle and see what it can take, making any adjustments that may be necessary. This tandem trike proto was made of electrical conduit and BMX wheels and took about two weekends to put together. We tested this trike at a campground for three days, beating it up over trails, down rough gravel roads, and even off road at times. It held up, even though there was no frame trussing and many of the welds were only half finished. My thinking is that if a poorly build proto can hold up to abuse, then a properly built final design would certainly hold up to just about any conditions. So, the next step was to turn proto into plan.

Turning paper into prototype

When I built the Viking Tandem Trike based on the original prototype, I made it a lot more durable and added many new features such as an unlinked transmission system, adjustable bottom brackets, dual disc brakes and under seat steering. The 1.25 inch conduit was replaced by 2 inch square tubing and the frame was properly triangulated for supreme strength. Building a plan from a prototype is a much longer process because every step has to be meticulously photographed and documented, but it is worth the effort when I see completed projects based on our plans being posted in the gallery.

So I am 95% into the plan stage on the Transporter Cargo Bike and only need to add the brake and shifter cables to complete the plan. But, the rain-man seems to have other plans, keeping me indoors as of late.

This is a typical site out here lately

The weather report has been practically the exact same for more than a month – a 40% chance of thunder showers and high humidity. What that means is that it spits rain once every few hours and dumps rain once a day. The grass is constantly wet, and my bike building shack smells like the back of uncle Jeb’s cabin…ack! I am at the point where I need a nice dry sunny day to get the final photos done, even if the rain holds off for four hours, I would be happy. Oh well, the apples and berry trees are sure enjoying the new rain forest, but the lawn is getting so tall it may take three days to hand mow the yard the next chance I get! I wonder, is there such a thing as an anti-rain dance?

~ Brad

DIY always gets attention

I’ve always had a passion for radical bike designs.

If you have been hacking things together for any length of time, then you probably know that your unique creations draw attention wherever you are. When I was in my early teens, I would string four or five scrap bikes together and my buddies and I would wobble down the street on my contraptions that often resembled bikes from Doctor Seuss books. Making it back home in one piece was a 50/50 chance because I usually only brazed my early bike hacks, but the one thing that was guaranteed was a lot of attention.  My intent was never to make something to draw a crowd, but I often found myself talking to a group of interested onlookers or even speaking into the camera on the evening news.

I took a long break from bike hacking after getting my first motorcycle (and job), but found myself back out in the garage in the year 2000 to rekindle my DIY roots and get my mind off the daily grind of living in the real world. I started collecting junk bikes and old power chair parts and concocted some cool bikes and robots out in the small garage just to have fun on the weekend. Oddly enough, I never took any photos or intended to publish these works. One day Kat suggested that I put some of the bikes up on my website AtomicZombie.com, which at the time was a home for electronics hacking stuff I was doing.

Getting youth interested in technology.

 

Well, within months I started connecting with some amazing people and realized I wasn’t the only one who enjoyed making art from metal, sometimes for fun, sometimes to be practical. It didn’t take long before the word spread locally, and we were dragging my creations to all kinds of events. The large video guided robots were always popular. I enjoyed inspiring young hackers to consider this great hobby. The robots were a natural crowd magnet since I controlled them from miles away via video link and could communicate to people by typing words into a speech synthesis station at the base, making the robot seem intelligent. Soon my remote robots’ main purpose was to draw in a crowd and baffle them with technology.

Photo op with some visiting teens from the USA after my World Record ride.

At one point, I decided to aim for a Guinness World Record, making the tallest rideable bicycle, and figure it would be fun and possible draw a bit of attention to the website which was now mostly dedicated to bike building. Well, I was certainly not ready for the storm that this thing generated once the word got out! I must have done a dozen live radio interviews, news casts and even a live spot on a a national broadcast of Canada AM . Tall bikes sure draw the crowds!

When the tallbike called “SkyCycle” made it to a full color page in the Guinness Book (along with my mug), I was shocked. I knew these crazy contraptions could draw interest, but I had no idea how far it could go. Even a simple recumbent bike like the Marauder would spend half the time parked as I explained the bike to interested people along a ride. No doubt, all you DIY enthusiast out there know what I am talking about.

When I think back to me pre-DIY days, I guess my inspiration did come from seeing others’ creations, although it was mostly in the form of photos from old Popular Mechanics books or the odd newspaper article. Now, with the internet jacked into our heads like The Matrix, it’s so easy to connect with other DIY folks and share advice, so the community is stronger than it’s even been. Back in the early 1980s I would have never thought that one day I would be saying, “Hey!” to a cargo bike builder in Africa and then a trike builder in Australia within a 15 minute span.

So, if you are a new builder just getting ready to roll open that garage door and head out on your new DIY creation, get prepared for the attention your work will draw.  You will now become the source of inspiration for a young generation of future DIYers, so make sure you pass along that attitude that drives us all, “Yeah, you can do this, too”!

~ Brad