SkyWalker is a radical two wheeler that allows the bicycle hacking adrenaline junkie to surf the skies while at the same time amusing or confusing the slack-jawed onlookers below. Sure, tallbikes are nothing new, and have been around since the 1800's, but SkyWalker takes things to new heights by allowing the rider to climb up and down the frame while the bike is in motion. What this means for tallbike pilots is that they no longer have to cling to a telephone pole to mount the bike, and worry about finding another pole when it comes time to dismount. SkyWalker is designed so that the pilot can control the bike from the ground, and all the way up to the top while climbing the built in ladder. Since the handle bars double as ladder handrails, the pilot is under complete control of the tallbike during the entire ascent.
Why would a person want to build and ride a 12 foot two wheeler you ask? To win a Darwin award? Train for the circus? Overcome a fear of heights? Set a world record? Who can say, but for me it has always been the same reason - because it's fun, and it beats sitting on my butt watching the tube!
The SkyWalker idea was originally drawn on a coffee stained napkin, and then later transferred to a 3D concept as shown in Photo1. The 3D model was used to get a better idea if the steering and transmission would actually work, since the frame was somewhat complex and involved a bizarre linked steering system. Normally, I just grab whatever scrap metal I can find and go nuts with the welder when making crazy bikes like this, but for SkyWalker I decided to follow the 3D plan exactly so I knew the final product would actually work as planned.
The photos presented here are somewhat low quality due to the fact that I built SkyWalker outdoors in early spring while the ground was still frozen, and did not actually intend to document it very much. Some of the photos were also taken at night, as I built the entire tallbike in one weekend just for a fun change.
SkyWalker is made of nothing more than a few standard bicycle components salved from the dump and a few lengths of thin walled electrical conduit from the hardware store. Even the curved tubes are nothing more than factory elbows. As for tools, I only used an angle grinder and a basic AC welder, nothing more. In other words, anyone with a pile of scrap bike parts and some tubing can do the same using any welder at all.
More cool projects can be found at: http://www.chopzone.com
Step 1: Photo 2 - Making the rear of the frame
The rear of the frame will be designed in a way similar to that of a standard bicycle - with stays that wrap around the wheel to hold it in place by the axle. Since I did not have a pipe bender, I simply hacked up some electrical conduit, and a few pre-bent elbows to make the part as shown in Photo 2. There are no measurements to give because I simply have no idea what they are. SkyWalker was built in a hurry using whatever scrap I had laying around, so I simply made things fit using the try it and see method. The large tube shown in Photo 2 is made from 1.5 inch conduit, and the stays are 1 inch conduit. There are two stays and two large tubes needed in order to form the rear triangle as will be shown later.
Step 2: Photo 3 - Making the top of the frame round
The top of the frame is made with a large 1.5 inch factory elbow cut and rewelded as shown in Photo 3. This rounded look makes the frame look more artistic, and keeps all sharp corners and snagging points to a minimum. A tallbike pilot would not want to have a shoelace or pant leg snagged in the frame during a dismount! The distance from the rear of the frame to this point is what will determine the overall height of the bike. I was shooting for 12 feet tall, which is a safe height for city riding. When I say safe, I am referring to the height of power lines, not the bike, dude!
Step 3: Photo 4 - Creating the rear triangle
The two rear pieces are joined together as shown in Photo 4 so they form a triangle. I decided to design SkyWalker with an impossible looking frame and remotely linked steering, so that it would confuse bystanders all the more. My design is certainly not the easiest way to build this kind of tallbike, but it does look cool. A huge A-frame would also work, but I wanted it to look as though there was no connection between the handlebars and the front wheel just to add to the confusion. As if seeing a madman on a 12 foot bike riding down the street wasn't enough!
Step 4: Photo 5 - The rear of the frame
The rear triangle is shown completed in Photo 5. The angle of the frame shown in the photo is the approximate it will be at when completed, allowing the rear of the frame to form a steep ladder. The frame could take on just about any shape imaginable, as long as the pilot's weight ends up centered between the two wheels. As for wheelbase, I think a the distance between the front and rear axle should be at least half the height of the frame for stability.
Step 5: Photo 6 - Hacking out some rear dropouts
The rear dropouts shown in Photo 6 were rough cut from some scrap 3/32 steel plate using a zip disc. Dropouts cut from an old steel BMX frame would also work fine. I was using a pair of heavy duty BMX wheels with 14mm axles, so I decided to make the dropouts equally as strong. The last thing you want at 12 feet is a frame failure.
Step 6: Photo 7 - Setting up the front of the frame
The front triangle will be another pair of 1.5 inch conduit tubes joined at the mid frame to form an inverted Y-shape for the frame. Again, I am building without any real plan or measurements, so I just strapped the rear of the frame to the fence and placed the front wheel and head tube where I thought it looked "right" and then cut the tube shown in Photo 7. Now my wheelbase is half the frame height, and the seat will end up approximately in the center of the two wheels. As for head tube angle, it is about the same as the angle of the rear tube whatever that may be. Most of the welding was done outdoors in the freezing cold as the frame was too damn tall to fit in the garage, and almost impossible to get onto the workbench.
Step 7: Photo 8 - Front triangle completed
Photo 8 shows the second 1.5 inch conduit tube installed to complete the front triangle. Now my tallbike looks like a giant inverted Y. Notice how there is no connection between the top of the frame and the head tube. Seeing this makes one wonder how the bike will be steered. The fence shown in the background is 7 feet tall by the way!
Step 8: Photo 9 - Making the frame rigid
The frame needs to by trussed to make it more rigid, as the long 1.5 inch tubes have quite a bit of flex. The frame is certainly strong enough without the trussing, but the" floppy" feeling would be a bit disconcerting at high altitudes, and could lead to chain alignment problems. By creating many small triangles using some scrap 3/4 conduit, the frame is made to be extremely rigid and strong enough to support four riders all at the same time. Yes, I tried this.
Step 9: Photo 10 - Stairway to the sky
Since the idea behind SkyWalker is to be able to climb while moving, a ladder of some sort will be needed. Using a few lengths of 3/4 electrical conduit, a crude ladder (Photo 10) is made. This ladder will be welded to the rear frame tube so that the pilot can get from the ground to the seat in approximately 10 steps. This ladder system worked out very well, and it was possible to get from the seat to the ground in under 5 seconds. On a conventional "pole hugger" tallbike, your only option is to find another pole for landing or face the consequences of gravity. For this reason, conventional tallbikes are usually made with seat heights of no more than 8 feet.
Step 10: Photo 11 - Ladder completed
The two ladder halves are welded to the rear frame tube as shown in Photo 11 so that the brave pilot can go from the ground to the seat without needing a pole to lean against. The angle of the frame makes climbing very stable, and it is almost impossible to lift the front wheel, even if you lean way back while climbing. The filly trussed frame is also extremely rigid, and could easily take 500 pounds all the way to the top.
Step 11: Photo 12 - This is the captain's chair
The seat post is welded directly to the frame on the curved section of tubing as shown in Photo 12. An adjustable seat could also be made by placing the seat post through the frame and welding a clamp to the tubing, but adjustability was not a huge concern here. It's not like I planned to run the Tour de France with this beast!
Step 12: Photo 13 - Lower steering bearing
The large handlebar loop will travel from the top of the frame to the bottom, allowing the pilot to steer the bike will ascending the ladder, so it needs an upper and lower bearing to hold it in place. The handlebar bearings are made from a pair of recycled bottom brackets taken from some scrap bicycle frames. Bottom brackets include a very strong axle and bearings, so they were perfect for this job. Photo 13 shows the lower bearing welded to the frame just above the front triangle on the vertical tubing.
Step 13: Photo 14 - Upper steering bearing
The upper handlebar bearing is welded to a leftover length of bent conduit so that it adds to the artistic look of the frame. This tube (Photo 14) will then be welded to the open end of the long tube that runs from the rear wheel to the top of the frame.
Step 14: Photo 15 - The bottom bracket assembly
SkyWalker needs a bottom bracket in order to allow the installation of the cranks, so the assembly shown in Photo 15 is made using another salvaged bottom bracket and some leftover 1 inch curved conduit tubing. This assembly will be welded to the vertical frame tubing at a position that allows pilots of average height to easily reach the pedals.
Step 15: Photo 16 - Cranks installed
The bottom bracket assembly is shown installed in Photo 16. The distance between the seat and pedals allows riders between 5'-8" and 6'-4" to easily pedal the contraption. Notice how the ladder stops just below the seat.
Step 16: Photo 17 - Making the handlebar loop
SkyWalker's handlebars are actually a large loop made from 1 inch conduit. This allows them to span the entire height of the frame, allowing the pilot to begin steering from the ground and climb up the entire ladder while maintaining total control of the bike. Well, total control may not be the best term to use, but you can certainly make it from the ground to the seat without any real problem. I often ascended the ladder while riding down a narrow sidewalk, so the ability to steer and climb was certainly acceptable. Photo 17 shows the 4 factory elbows and length of 1 inch electrical conduit used to make the handlebar loop. The handlebar loop needs to be wide enough so that it does not interfere with pedaling while steering.
Step 17: Photo 18 - Handle bar mounting system
To mount the top and bottom of the handlebar loop to the bearings, a steel crankset is hacked up for the ends of the arms that contain the square holes. As shown in Photo 18, this small part is welded to the center of the handlebar at the top and bottom where they will connect with the bottom bracket axles used as handlebar bearings.
Step 18: Photo 19 - Handlebars completed installed
Photo 19 shows how the handlebar loop is installed into the top and bottom handlebar bearings. There is plenty of room for the pilot's legs and pedals, even when the handlebars are turned to a full 45 degrees in either direction.
Step 19: Photo 20 - Adding a chain guide pulley
One thing that did not show up on my 3D model is the chain interference problem. To solve this minor chain rubbing annoyance, a small idler pulley was installed as shown in Photo 20 so that the chain would not rub on the rear frame tubing. This pulley also helps to keep the chain nice and tight so that a derailment will never be a problem. As I have learned from past mistakes, a loose chain on a tallbike is not a good thing.
Step 20: Photo 21 - Chain routing sprockets
To keep the clean flowing lines of the frame free from the chain line, I added a pair of kid's bike sprockets to the top of the frame as shown in Photo 21 so the chain would run inside the frame rather than dangling in front of the frame. These small sprockets are actually what is leftover after hacking of the crank arms on the crank sets.
Step 21: Photo 22 - Linking the steering system
To make the impossible looking steering system work, a pair of spherical bearings (ball joints) are welded to the end of a control rod that runs from the lower handle bar bearing to the front head tube. The control arms are made using a bit of crank arm at the rear and a hacked up bicycle gooseneck at the front. Photo 22 shows the handlebar side linkage as well as the head tube linkage (inset). Because the front control arms is made from a bicycle gooseneck, it allows the alignment of the handlebars and front wheel to be adjusted so that the wheels is tracking straight ahead when the handlebars are in their idle position.
Step 22: Photo 23 - SkyCycle and Skywalker
Shown in Photo 23 is a shot of my SkyCycle tallbike along side the unpainted SkyWalker tallbike. The SkyCycle was an original design from my "Bicycle Builder's Bonanza" book (http://www.atomiczombie.com/product-bonanza.htm) and was shown on page 134 of the 2005 Anniversary edition of the Guinness Book of World Records. In 2005 SkyCycle was awarded the World's Tallest Ridable Bike record. As you can see, SkyWalker is only a few feet shorter.
Step 23: Photo 24 - Adding the bling
What good is a rolling piece of art without your personal signature? Because SkyWalker attracts loads of attention, I figured it would be a good idea to add my website address to the frame so other local (loco) bike builder's could get a hold of me. The banner (Photo 24) is made of 1/16 inch sheet metal cut on a plasma table.
Step 24: Photo 25 - High contrast paint job
To make SkyWalker stand out against the bright daytime sky, I decided to paint it completely black. As you can see in Photo 25, the dark frame really stands out against a light colored background. At first glance, the complex design does not reveal any indication as to how it is actually possible to steer the beast. Many people think I have to lean to steer the bike.
Step 25: Photo 26 - Yep, that's my home in cyberspace!
SkyWalker turned out to be extremely easy to ride once you learned to trust the bike. With a few pushes, you could casually climb the ladder while the bike rolled ahead, keeping it under total control. Once at the top, you jump in the pilot's seat and start to pedal. getting back down was simply the reverse procedure. If you visit the website shown on the banner (Photo 26), you can see a video of SkyWalker in action.
Step 26: Photo 27 - SkyWalker is also a vertical tandem
Because of the rigid frame, SkyWalker can carry as many riders that have room on the ladder. At one point, I had four people (including myself) hanging off the frame as I rode around. Once you beat your fear of heights, SkyWalker rides exactly like any bicycle, and it gives you a view of several blocks in all directions. I often took the tallbike out on the street and felt very safe as I could see so far ahead, and I was certainly visible in traffic to say the least. When I had to stop at an intersection, I just climbed down the ladder - a process that took about 5 seconds. Getting back to the top was as easy as giving the frame a push and then climbing back up the ladder.
I think SkyWalker really turned out well considering it was hacked together in a weekend with no real plan using basic tools and scrap bicycle parts. I am now working on a 25 foot tall bike using the same basic design as SkyWalker, and plan to break the Guinness record again sometime soon. The new tallbike will be called "Bad Altitude", and will feature two pairs of cranks so the pilot can get the bike up to speed before ascending the 25 foot ladder.
Well, there you have it! Crazy ideas turned into rolling art using nothing but scrap from the local dump and a few basic tools. You don't always have to have a logical reason for building crazy contraptions - sometimes it's just about excersizing your creativity and having a good time!
Brad from AtomicZombie.com
Step 27: Action sequence from the video
Here is a few frames from the video on our website. Yes, you climb up and down the ladder while the bike is in motion. This is a much better idea than hugging a pole - a problem with non ladder tallbikes.
The video can be seen at http://www.atomiczombie.com
There are also many other cool tallbikes from builders around the world in our gallery.