Once in awhile I get the urge to create a new wild and crazy cycle based on some idea from the many sketches I have collected over the years. Sometimes these bikes work out as planned, creating new and fun ways to move from point A to point B, and sometimes these creations fail, either in a huge flop, or a blaze of glory where the crash test pilot becomes acquainted with the pavement. This time, the plan worked out, resulting in a very unique and fun ride that is both challenging to master, and capable of some off-the-wall maneuvers.
Step 1: You Will Need a BMX Front Wheel and a Caster Wheel
The SpinScooter is based loosely on our SpinCycle Stunt Trike, allowing the front wheel to steer the vehicle as normal, but also allowing some out of control steering by allowing the rear caster to steer the rear of the vehicle. This front and rear steering gives the feeling of riding on ice, or doing a burn-out on a fast motorcycle. By shifting your weight around and controlling the front wheel, you can get the SpinScooter to do 360s, steer into a drift, or behave like a regular kick scooter. When you are first starting out, you will also learn creative ways to fall on your back!
As shown in Figure 1, you will require a pair of wheels - a standard front 20 inch BMX wheel and some kind of caster wheel like the ones you would find on the front of a shopping cart. The larger the caster, the more fine control you will have over the scooter, so choose the larger diameter caster wheel you can find. Also, rubber or air filled caster wheels are better than hard plastic casters for this project. The caster wheel shown in Figure 1 has a diameter of 8 inches and was taken from an old wheelchair.
Step 2: Front Fork and Required Bearing Hardware
Just about any front fork will work for this project as long as the bearing hardware fits the fork stem. I wanted a bit more height on my scooter, so I chose a beefy looking 26 inch front fork as shown in Figure 2. The bearing hardware includes two ball bearings, two bearing cups, a top threaded bearing race, a lock washer and a top nut. Notice that the bottom bearing race is slightly larger than the top, and when installing bearings, the balls go into the cups so that the flat part of the retainer is at facing up.
Step 3: Find a Matching Head Tube
You will also require a head tube that will match the length of the fork stem. A matching head tube will be about 2 inches shorter than the fork stem to allow all of the bearing hardware to install properly. If the head tube is too long, you can always cut off a section, and may also be able to cut a bit of the threaded fork stem if it is too long. I hacked an old mountain bike frame from the head tube shown in Figure 3, and it looked to be about the right length to match.
Step 4: Test the Fork Hardware
When the fork hardware is installed as shown in Figure 4, you should be able to hold the head tube and spin the forks freely with very little friction. If the forks seem to stick, then either your bearings are installed the wrong way or some of the hardware is not of matching size.
Yes, like all mechanical things in life, there are several sizes that look almost identical, yet will not work together properly. There is an underground committee of engineers that meet in secret to ensure that many similar standards exist in order to anger and confuse all those who dare to take things apart. Don't let them defeat you!
Important: All welding processes produce fumes and gases to a greater or lesser extent. Galvanized steels produce added fumes from the vaporized zinc coating. Fumes from welding galvanized steel can contain zinc, iron and lead. Use precautions, including high-velocity circulating fans with filters, good ventilation, air respirators and fume-extraction systems.
Step 5: Making a Curved Frame the Easy Way
The SpinScooter is a very simple project that can be built using any available 1.5 inch or larger tubing you have on hand. Your only real goal is to place the front wheel and forks in a position similar to that of a regular bicycle, then create some place to plant your feet. The distance between the front and rear caster is about 12-16 inches. Seriously, don't worry about the angles and measurements, just build the scooter using the parts you have on hand. I did not plan any of this project, and there is no doubt that it can be modified to perform better, so use your imagination and just start cutting up tubing!
I had some spare 2 inch conduit elbows in my scrap bin, so I decided to chop them up and welded them end to end in order to make a nice curved frame as can be seen in later photos. To calculate the lengths and dimensions of the main frame, lay the wheels on the ground so that the distance between tire edges is about 12-16 inches and then fill in the blanks. As for head tube and caster angle, anything between 10 and 15 degrees will work just fine. The slight angle of the caster gives your scooter a bit more control for straight line riding, and the head tube angle helps with fine control of the vehicle. Again, feel free to alter these angles to see what happens!
Step 6: Weld the Elbows to Create a Frame
My frame is shaped like the letter S as shown in Figure 6 after cutting and welding the conduit elbows together end to end. Square tubing or heavy bicycle tubing would also work, but tubing with a diameter of less than 1.25 inches might be too thin and could bend, so keep that in mind. To keep the two elbows aligned, they were placed on a flat surface and initially tack welded together. The entire joint was then completed, ensuring proper penetrations for strength.
Step 7: Lay Out the Rest of the Frame
Figure 7 shows the extent of my plan. Pplace the parts on the ground and fill in the blanks. I wanted my feet to be only a few inches from the ground so that it would be easy to operate the unit as a standard kick scooter, so the pegs were placed to allow a 3 inch ground clearance, enough to avoid scraping the ground during tight corners and spins. Also notice how the front head tube is angled slightly forward while the rear caster is angled slightly backwards. This 10-15 degree caster angle allows for more stable control when actually trying to move in a straight line.
Step 8: The Rear Caster Wheel Support Arm
To join the rear caster wheel to the frame, a small 1 inch conduit tube was cut to a length of 8 inches and welded to the caster wheel's tiny head tube. If you are using a shopping cart caster, then it will have a bolt, not a head tube and will require a hole to mount it to your frame tubing. A piece of flatbar or angle iron would also work for mounting a bolt style caster to your scooter.
Step 9: Add Strength Through Triangulation
The 1 inch diameter tube that connects the caster wheel to the frame needed to be strengthened, so a bit of rod was cut to form a triangle as shown in Figure 9. This gusset or truss will add amazing strength to the caster support arm, which may not have been strong enough to withstand the weight of a "big kid" by itself.
Step 10: Rear Caster Wheel Installed
The caster support tube and truss rod is shown welded to the frame in Figure 10. Initially tack weld all parts together so you can visually inspect alignment. Both wheels should be inline when they are in the straight ahead position so that your scooter tracks properly when attempting to drive in a straight line. "Attempting" is the key word here!
Step 11: Head Tube Welded to the Main Frame Tube
Once you have all of your bits and pieces tack welded together and have checked for wheel alignment, complete all welding by going around the entire joint as shown in Figure 11. Notice the same small truss rod has been installed at the head tube joint to add strength to the scooter in case of a front end collision with an "immovable object" such as a wall or curb. This scooter was born to crash, so the stronger you can make the frame, the longer it will survive.
Step 12: Both Wheels Installed
The main frame is shown in Figure 12, with both wheels installed and all joints fully welded. Now, all you need is a place to rest your feet and a set of handlebars to hold on to.
Step 13: BMX Style Handlebars Work Best
A pair of tall BMX style handlebars will probably work best for this project, as you will require a little height rather than having to bend over to steer. Figure 13 shows a typical 8 inch tall set of BMX handlebars and a matching gooseneck to hold them. Also note that goosenecks come in two sizes, and although the larger sized goosneck will not fit into the smaller sized fork stem, the smaller gooseneck will indeed fit into the larger fork stem, but will eventually work its way free or fall out. This is more evil doing by the secret non-standards committee, so be careful. There should be no play between the gooseneck tubing and the fork stem.
Step 14: Foot Peg Options
To stand on your scooter, you will require some kind of foot peg or platform. There are many options, including BMX pegs or even a skateboard plank, so use your imagination. Figure 14 shows two options I considered - a standard round BMX peg and a platform mate of some 1/4 inch thick flatbar. I opted for the flatbar platform as I wanted to use the foot pegs for some other project later. Remember to round off all sharp edges on your projects, especially ones that are guaranteed to be smashing into you at high speed like this one will. The pavement hurts enough, so you don't need to be cut to shreds by your vehicle as well!
Step 15: Install the Foot Platform
The flatbar foot platform is shown installed in Figure 15 after rounding off the sharp edges using a grinder disc and a sanding disc. The flatbar foot peg option worked out better than the BMX foot pegs, as it kept my feet closer to the ground, making it easier to reach down and kick the ground for acceleration.
Step 16: Carve Out Some Treads on the Platform
A little grip tape will help keep your feet in place, or you could take a grinder disc and carve the top of the plate as shown in Figure 16 to add a little more grip. Grip tape can be found at any skateboard shop and works perfectly.
Step 17: Ready to Be Painted
The completed and ready to be painted SpinScooter is shown in Figure 17 after many runs up and down the only clean section in my garage. Although I crashed several times into the wall and the giant pile of twisted bicycle scrap, the SpinScooter showed great promise, able to scoot in a straight line when I wasn't attempting to do a 360. I though about putting a front hubmotor and battery pack on the scooter before painting, but that little voice in my head that helps keep me alive said, "Dude, what are you totally insane?!" I decided that kick speed would be the best option!
Step 18: Ready to Roll!
After a fresh coat of paint, the SpinScooter was ready to ride. I paint all of my bikes with department store spray paint, and if you take the time to use a good spray primer and let coats cure overnight, you can have a very professional looking paint job for a few dollars. The bright yellow gave the SpinScooter a tamer look, as if to mask its evil personality.
Step 19: Trying to Get Into a Drift Slide
There is not much to learn when first trying the SpinScooter, but do be prepared to wipe out! Because you can pull a complete 360 while moving (see the SpinCycle videos), you will need to find that "point of no return" where the combination of front and rear steering overwhelms the vehicle, sending you into a vortex of pain.
After a bit of practice, I was able to fishtail, 360, t-slide, and drive without ending up on my back. It takes a bit of getting used to, but the SpinScooter does offer a ride like no other scooter, that's for sure. As for just moving in a straight line, the SpinScooter does well there, behaving like and decent kick scooter should.
Recommended: wear a helmet and protective gear that you would normally wear while inline skating or skateboarding. Always be safe while you're having fun.
Step 20: Not for Those Who Suffer Motion Sickness!
Have fun with your new wheels, and make sure to send in a few photos and videos of your creation! If you think this project is a bit too scary for your liking, then have a look at our SpinCycle Stunt Trike, which will allow you to do all of the 360s and spin slides you want without the risk of falling over due to its three wheel configuration.
~ Brad (RadBrad) and Kathy (KoolKat) McGowan
Step 21: Build Your Own!
Even if you have never taken a bicycle apart or handled an angle grinder, you can learn all of the skills needed in order to create your own recumbent bikes, trikes, choppers, tandems, trailers, tall bikes, fun bikes and more in a few weekends using inexpensive tools and standard bicycle components. Our plans include many styles of human powered and electric vehicles, and most projects can be built for a fraction of the cost of a new comparable vehicle.
Build a low and fast recumbent tadpole trike, or a sturdy load carrying trike from our plans. You can race local traffic by building a lowracer from our recumbent lowracer plans, or look cool by building one of the radical chopper bicycles from our chopper plans!
None of our bike or trike plans require expensive or hard-to-find parts. You can easily make changes to suit your needs or work with the materials you have on hand. Any standard store welder and a few handheld tools are needed to create your own choppers, custom trikes and recumbent bicycles from our plans, so dive right in and let the sparks fly!
Check out some of the free, simple projects and tutorials above if this is your first time building a bike or trike from plans.
Free DIY bike chopper projects: http://www.chopzone.com