Building a Front Wheel Drive recumbent lowracer – England

recumbent lowracer

Ian Swindells of England built this lowracer from scrap and custom parts.

Ian W. Swindells (forum member swizz69) always wanted a recumbent bicycle. Researching online brought him to the AtomicZombie builders forum.

After learning about the Warrior Tadpole Trike, Swindells was motivated to design and build a Front Wheel Drive recumbent lowracer. In a feature article for the AZ newsletter, Swindells discusses the project and the challenges along the way.

Read his story>>

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Chopper mania – USA

chopper bike

Fantastic detail on this bicycle chopper.

 New Yorker and AtomicZombie member, Kempracing, has an addiction. But, don’t worry, it’s a good one.

He loves to design and build choppers. It doesn’t matter if they’re on two wheels or three. Each one is unique. Kempracing puts a lot of thought and care into his bikes.

Check out the detailed web design of this chopper. He built and donated this chopper for a raffle at the Howe Caverns Bicycle Show and Swap Meet in New York this past July. A lucky winner pedaled off with this beauty.

chopper trike

A custom built chopper trike for the Mrs.

And, an embedded star burst heart on the trike he built for his wife, Patty. Awww.

See more of kempracing’s custom built choppers.

Tay’s homemade chopper trike – England

Tay helped his dad build this chopper trike from scrap bike parts.

Submitted by AtomicZombie forum member and bike builder, Naughtyboy.

“We built this because my youngest two kids needed bigger bikes and they both love workshop time with daddy.

One of the kids from school turned up on a shop built chopper, so Tay looked it over and said, “Me and my dad can build (one) better.”

We’ve built all sorts from scrap wood and metal and they have even helped me with rebuilding an old Land rover.

Tay decided he wanted a trike after seeing my Gladiator (chopper trike) plans, and he also looked through my 15 other plans to plan future bikes. The front is based on the Gladiator chopper trike and the rear, I think, was based on the DeltaRunner Recumbent Trike, but flipped over.

The forks are made from 16mm od x 8mm id blow pin shafts left over from machine re-furb at work. Suspension is made of old trampoline springs I found. The handlebars are from an old rotavator which I’m planning on using engine on quad-cycle (so many ideas, so little time).

I had to turn some sleeves to fit them as id was bigger than od of forks. Tay helped with drilling on lathe. Front wheel is 20″ and back started as the same size, but are now 26″ as we needed the smaller one for his little sister’s trike.

I just wish he would let me finish painting it, but he’s too busy racing on the road with his mates! I am impressed with how tight a turning circle it as and how fast he can go.”

Read more about this project at the builders forum:
http://forum.atomiczombie.com/showthread.php/9247-happy-boy

More pictures in the bike builders gallery:
http://forum.atomiczombie.com/gallery/browseimages.php?do=member&imageuser=5871

www.AtomicZombie.com

Bike builders newsletter online – Oct 30

bike builders news

Feature article by David Monk: Building the AtomicZombie Warrior Trike

Parts for your bike projects: axle adapters, disc brake adapters, hub flanges, head tubes and bottom brackets

Bike builders community: Hot topics and intriguing conversations.
Bike builders gallery: New additions. Upload your own photos.
Bike builders feedback: We love to hear from you.

Free DIY tutorials: Many in PDF format
AZTV webisode: There and Back Again: A Zombie’s Tale

This and archived newsletters are here: http://atomiczombie.com/NewsLetters.aspx

 

diy bike plans

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

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