Baseball cards and clothespins are CLASSIC , but when I was inspired to make my son's bmx roar like a real 110cc dirtbike, I couldn't pass it up! He had been wanting to get a dirtbike for quite a while, but not quite ready to take on the responsibility that comes with such great power. (We were listening, Uncle Ben!)
So I thought I would try one of these to quench his thirst for 2-stroke madness just a little longer....
This is designed to fit a 20” BMX bike wheel, but could easily fit a mountain bike, or be scaled down for a smaller bike. I think 1” pipe would work well on a 16” bike wheel.
Step 1: Materials
I'm sure everyone knows about PVC, but in case you're wondering, ABS is the black tubing usually near the PVC in the plumbing aisle. Mostly used for draining and other low-pressure stuff. Each type uses their own special glue, so that may be a deciding factor. I chose PVC this time, 1) because I already had the glue, and 2) I had made one of these once before in ABS, and wanted to see the differences to be sure it was the same either way.
I had most of the hardware in my garage, as well as the primer and scrap steel. The rest I purchased, and spent less than $20 total. The paint and decals alone were $10, so all the fittings and pipe were relatively cheap.
Start by digging around the garage/basement/lab and see how much of this you already have laying around, then make a run to your local hardware store:
• 1 ½” pipe, about 12” long. My hardware store sold it in 24” segments.
• 1 ½” wye, be sure each of the three ends are all the same size!
• 1 ½” 90* elbow.
• 1 ½” 45* street elbow. This means one end is male, the other female. I don’t know why.
• 1 ½” X 1” bushing. It doesn’t matter if the hole is threaded or not, but the outside needs to be a slip fit like the rest of the fittings. Try to get one that has solid walls.
• A piece of scrap steel, about ½” to ¾” wide, and about 10” long, sturdy but bendable in a vise.
• A piece of sturdy plastic. My favorite is five-gallon buckets or lids. Today I have a laundry soap lid.
• A lag-threaded eye-bolt, 1” long.
• A pipe strap. Rubber coated is best. The hole on the end needs to be a close match to the eye-bolt.
• A small screw and nut to fit both the eye-bolt and the pipe strap. I used ¼ - 20 with a nylok nut.
• 4 small pan head sheet metal screws, size 8 or 10 are good.
• A washer to fit one of the sheet metal screws, about ½” to ¾” wide OD.
• Primer to match your pipe material (PVC or ABS?)
• Glue to match your pipe material. They do make a general purpose glue that is made to bond ABS and PVC together, but not always available. This can be handy if you can’t find all the fittings in one type.
• Chrome spray-paint.
• Decals of choice.