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Build the OldSkool Retro ChopperOld Skool Attitude chopper brings back the golden age of chopper building when most bicycles had only a single speed, one brake, balloon tires, and nice flowing lines in the frame. Your daddy would remember the days when he and his buddies would take that old bicycle, extend the forks by hammering another pair end to end, replace the front wheel with a smaller one, and then strip all unnecessary parts from the frame. Those builders who had access to a welder may have even modified the frame or forks to adjust the rake, which is what I plan to do here. The fun thing about this project is that all of the parts are true to the era, right down to the 1970s exercise bike that I used for parts.
Figure 1 - A vintage 1970s single speed frame Figure 1 shows the vintage 1970s single speed frame that I found at the dump one day while scavenging for parts. I was just a young "whipper snapper" when these bikes were on the road, but I do remember seeing them chopped and modified, ridden by garage hackers of the day. I thought it would be cool to salvage this old frame from the mud and give it the life it always wanted, keeping true to the style of the era from whence it came. I hade an old 1970s exercise bicycle sitting in the back of my garage, as well as a banana seat, an old single speed wheel, and a vintage bicycle light, so this project was certainly possible. 
Figure 2 - A simple frame modification I planned to add longer forks to the chopper, but did not want it to lean back too much, so a simple frame extension would be necessary in order to increase the rake and length of the frame, which would keep the bottom bracket roughly at the same height to the ground. As shown in Figure 2, the original head tube was removed and two pieces of conduit, equal in diameter to the original frame tube were fit in place. The original head tube could not be reused due to the lugged construction, which leaves huge holes in the head tube and contaminates the joint with brazing filler. Another head tube from some scrap frame was used to replace the original head tube. 
Figure 3 - Installing the top tube extension Figure 3 shows the top tube extension tack welded to the frame. This 8 inch long piece of conduit has the same diameter as the original frame tubing, so it would be easy to seamlessly integrate it by grinding away the weld material. Head tube angle was also increased to allow the new forks to have quite a bit of rake so that the frame would not be lifted at the front, creating a skyscraper style chopper. When doing these ad-hoc frame modifications, it is a good idea to place the parts and wheels on the ground to make sure your final product will have the angles and dimensions you are after. Bottom bracket height is another matter of concern, as you don’t want your pedals to hit the ground around corners. 
Figure 4 - First tube completely welded The first extension tube was completely welded at the top tube joint as well as the head tube joint as shown in Figure 4. The head tube was checked for vertical alignment with the seat tube just after the first few tack welds were made. 
Figure 5 - Cleaning up the welded area To make the final product look like it was born to be a chopper, the frame welds are ground completely flush and then carefully cleaned with a flat file. The resulting tube extension as shown in Figure 5 is completely seamless. When making a seamless joint, rough grind the weld material with a grinder disc, being careful not to create a low spot, and then finish with a hand file, so you do not accidentally take away any excess material. The seamless joint will be just as strong as the original weld, as long as your penetration and welding technique are adequate. Chances are that you will have to fill in a few tiny holes and the grind a little more, but it is all for the love of the craft. 
Figure 6 - Adding the down tube extension The missing section of down tube will be filled in with another piece of electrical conduit, this time a section of factory elbow. As shown in Figure 6, the elbow is cut so that the curve joins the original down tube as a butt joint and then curves up to meet the head tube. If you have a tube bender, you could also make your own curved extension tube. 
Figure 7 - Frame modifications completed Figure 7 shows the completed frame modifications after cleaning up the down tube welds at the seam. Once painted, there will be no detectable seam where the frame was cut and welded, making the final product look very professional. I’ll bet your dad never had a chopper frame of this quality! 
Figure 8 - Official vintage exercise gear To keep with my silly idea of only adding vintage parts to the Old Skool chopper, I dug out this vintage 1970s exercise bike form the huge pile of scrap at back of my garage. I could almost hear ABBA songs playing in the background as I gave the cranks one last spin before heating up the zip disc for total annihilation of the unit. I decided to use the handlebars of the exercise bike as chopper forks, integrating the actual handlebars and fork legs as one smooth flowing line. Those massive cranks would also fit the new chopper perfectly, as they were also the correct style for this project. 
Figure 9 - These parts will become the new forks The two front tubes that form the handlebars and front stand on the old exercise bike were hacked from the frame as shown in Figure 9. I also cut the legs off of some really old kid’s bike forks so I could weld them to the end of the new forks, creating that nice tapered look that all forks had back in the day. Also shown in Figure 9 is a fork stem that will fit into the chopper frame’s head tube, allowing me to create the new long forks. 
Figure 10 - Using the front wheel as a guide To create the new flowing front forks, the two amputated fork legs were bolted to the front wheel axle and then tack welded to the exercise bike tubing. Figure 10 gives clear image of how I plan to integrate the curved tubing into one continually flowing handlebar and fork unit. The front wheel is used as a guide to make sure that each fork leg and handlebar half had the same shape and angle. 
Figure 11 - Adding the fork stem To join the new long forks to the chopper, a fork stem would need to be connected to both tubes in order to create a useable pair of forks. The fork stem and two small tubes shown in Figure 11 will be used to complete the assembly, securing the two fork legs to the head tube. The two smaller tubes will be welded to the fork stem at 90 degrees to each other and are at whatever length is necessary to place the fork legs parallel to each other as will soon be shown. 
Figure 12 - Fork tubing welded The two small tubes are welded to the base of the fork stem as shown in Figure 12 so that there is a 90 degree angle between them. Because the front wheel is being used as a guide to keep the two fork legs parallel to each other, it is easy to calculate how long each of the two small tubes needs to be. The ends of both tubes are ground out to conform to the fork legs, making the joint easy to weld. 
Figure 13 - Installing the fork stem Figure 13 shows how the new fork stem joins the two fork legs together so that they run parallel to each other once held in place by the front wheel axle. The position of the fork stem will determine the length of the forks and the height of the handlebars in relationship to the frame. I decided to keep the forks as long as possible, placing the handlebars very low for a “low and lean” look. The fork stem should also run perfectly parallel to each fork leg in order to keep the forks aligned with the rest of the frame. 
Figure 14 - New forks installed The new forks can now be installed as shown in Figure 14, although it is not a good idea to put any weight on them just yet. The two small tubes that connect the fork legs to the fork stem are not strong enough to take any real weight, so some extra support will have to be added between the top of the fork stem and the fork legs. This dual support system is often referred to as a triple tree fork. Also, notice how low my handlebars are in relation to the rest of the frame. The rider will have to hunch over to reach the handle bars, but whoever said a chopper should be comfortable? It’s about attitude, not comfort! 
Figure 15 - More recycling of parts The top of the fork stem needs to have some kind of support in order to keep the two lower tubes from bending once weight is on the frame. I found two reflector mounting brackets as shown in Figure 15, which when bent the appropriate way, would fit perfectly between the top of the fork stem and the fork legs, assigning the needed support. You could also make a triangular plate with a hole for the fork stem to do this job as well. 
Figure 16 - Top support brackets installed The two reflector brackets are shown installed on the fork stem in Figure 16, adding the needed support the fork legs. A small hole will be drilled in each fork leg so a machine screw can secure the brackets to the fork legs, giving the entire fork assemble much greater strength. Now the fork legs can take the weight of a rider safely. 
Figure 17 - Staying true to the era Well, that’s pretty much it. To keep true to the era, I added a banana seat, single speed coaster brake rear wheel, vintage bicycle light, and the crankset from the old exercise bike. Oh, and most choppers from back then had a front wheel that was much smaller than the rear, so I added a 20-inch front wheel. Figure 17 shows the Old Skool chopper before painting. 
Figure 18 - Faded green and Gypsy Chrome The frame was painted a nice faded green (Figure 18), and the forks were sprayed using what is referred to as Gypsy Chrome – silver paint. Notice how the frame shows no signs of modification due to the careful cleaning of all the joints. 
Figure 19 - Just like your old man used to ride The finished Old Skool chopper is shown in Figure 19, complete with a rear balloon tire, and retro brown handle grips. Since most bicycles of the 1970s had fenders and a chain guard, chopper builders of the day would remove them to be rebellious, which is why this chopper has neither. 
Figure 20 - OldSkool... Circa 1920 The Old Skool chop actually rode very well, considering the ultra low handlebars and extended forks. With that huge balloon tire and coaster brake rear wheel, you could lock up the wheel, and fish tail like crazy around the corner, leaving a thick black trail of rubber on the road. The wheelie ability of this chopper was intense thanks to the banana seat, allowing the rider to shift the center of gravity over the rear wheel. Next time you find a bunch of retro junk at the dump, bring some attitude back from the past. Hang onto your welding hats, kids. The next project will appeal to the young chopper enthusiasts. Brad (RadBrad) and Kathy (KoolKat) McGowan. |
