SideWinder Swing Bike

A tricky stunt bike that can fold in the center.

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.

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