Sidewinder Swingbike - Part 1 of 4

Photo 1

The SideWinder is a bizarre folding bicycle that pivots in the center of its frame while in motion, causing the wheelbase to shorten up for some seriously wacky steering tricks. You can turn the SideWinder around in about 2 feet of space, making it slink around corners and spin around in place until you are too dizzy to keep riding! When it’s not folding around corners, the bike handles just like any regular bicycle, so it can be ridden for long distances under normal control.

You can use practically any ordinary bicycle frame in order to build your own SideWinder, but this lady’s frame shown here is optimal due to the placement of the top tube and down tube. Start by chopping the frame as shown here at the end of the down tube where it meets the bottom bracket and at the end of the top tube where it meets the seat tube. Once you cut the tubing, use a sanding disc or hand file to remove any sharp leftover tubing at the bottom bracket and seat tube joint.


Photo 2

There are no strict measurements and angles when building the SideWinder, so you need to install your wheels and cranks to determine the position of the frame tubing based on the parts you are using. The goal is to build a frame that pivots just ahead of where you knee will reach its furthest when pedaling and to ensure that the pedals have about 3 inches of ground clearance just as they did on the original cycle. As shown in this photo, the original head tube is relocated so that it is about 14 inches from the seat tube, at an angle very much the same as it was originally. This slight upward head tube angle helps the frame stay in the non-folded position when you want to ride it normally.

The other piece of tubing shown here will extend from the pivot to the head tube that will carry the front forks and handlebars. The front steering head tube is also placed at the same angle as on a regular bicycle, so both head tubes are at the same angle.


Photo 3

Weld the chopped front frame section back to the rear frame section as shown here, placing the head tube about 14 inches away from the seat tube at the same angle as it was on the original frame. If you are using a ladies bicycle frame like I am, then you don't have to alter the front section of the frame - just flip it upside-down and it will work perfectly. If you are using a standard diamond frame, then you need to cut one of the tubes so that the lower tube forms a 90 degree angle with the seat tube as shown here. Of course, none of these measurements are absolutely critical, so feel free to experiment.

Sidewinder Swingbike - Part 2 of 4

Photo 4

To create a frame that can smoothly fold in half in the center, we will utilize the original fork stem since it already fits perfectly in the head tube. Cut the fork legs from the fork stem right at the crown area and then clean up the leftover metal with a grinding disc. Find a 14 inch long piece of frame tubing or conduit and then weld it at 90 degrees to the fork stem at the crown area where you just removed the fork legs. At the other end of this tube, you will install another head tube that will carry your front forks and handlebars. As shown in the photo, both the fork stem and the new head tube will form a 90 degree angle with this new tube. The size of the new head tube is not important as long as it fits the front forks you intend to use.


Photo 5

Once you have welded the lower swingarm tube to both the base of the fork crown area and the front head tube, install another tube to become the top swingarm tube as shown here. This tube will be welded to the base of a steel gooseneck that has had the clamp section ground off and then to the front head tube as shown here. One thing to note is that you will not be able to remove any of the swingarm fork hardware once this welding is done, so clean and grease your bearings and install all of the hardware properly before welding this tube into place. These tubes can be recycled from another frame or you can use thin walled electrical conduit like I did.

Sidewinder Swingbike - Part 3 of 4

Photo 6

Here is the completed and unpainted SideWinder ready for its first test run. For best results, I found that a taller set of handlebars were optimal, and did not bother with any gears or brakes since this was mainly going to be a parking lot fun bike. To make a single speed, put the chain on the center chain ring on the rear wheel and cut the chain to fit. If you do intend to add a brake to your SideWinder, then only add a rear brake as a front brake will cause an instant and brutal jackknife to occur due to the front end wanting to fold into the rear of the frame.


Photo 7

The initial test ride went as well as can be expected on such a crazy bike, so I painted the frame and switch to a banana seat to make it easier to shift weight around when doing stunts. The SideWinder ended up being a very fun bike to ride, once I mastered the ability to pull the front wheel only inches away from the rear wheel while in motion.


Photo 8

The SideWinder can fold almost right in half, making it a unique variable wheelbase bike that can turn around in about the space of a single sidewalk block. By shortening the wheelbase, the turning circle is drastically reduced, making the sidewinder seem as though it can spin in a circle or slither around a corner in ways that defy logic.

Sidewinder Swingbike - Part 4 of 4

Photo 9

Find a nice quite place like a parking lot for your initial test ride (crash test). You will probably find it easy to ride the SideWinder while it is in the relaxed (straight forward) position since it is not much different than a regular bicycle except being slightly longer. Get moving at about a jogging pace and then pull the handlebars towards your body as you kind of swing to once side, turning a bit in the same direction. At this point, the frame will pivot, and you can bring the front wheel closer to the rear wheel. If you keep steering straight ahead, then the bike will tilt backwards yet still ride somewhat normally, although it will look like a train ran over your frame to onlookers!

Once in the folded position, try to steer towards the direction of the frame pivot, and you will be able to zip around in a very small circle. Of course, you will probably jackknife and face plant a few times as you get used to the odd feeling of riding a folded bike with a 12 inch variable wheelbase! Keep practicing and you will be able to do all kinds of bizarre turns and slithers in no time.

One of my favorite things to do on the SideWinder is to ride towards someone so everything looks normal, but just as I get within a 20 foot distance, I crank the frame into a tight fold and do a few loops, switching to the other side right after to complete the tricky maneuver. To the unsuspecting onlooker, it would appear that my bike just experienced a total frame failure, but somehow I was able to keep riding it! Of course, after a few turns, it becomes apparent this is no regular bicycle, but in fact a circus ready stunt bicycle!


Photo 10