I've had my hands full with my four wheeled projects lately and I haven't been giving my little "cafe" motorcycle; a DKW RT125 much attention. I recently decided to build a set of clubman style drop bars for it. My problem with off the shelf parts are that I usually end up modifying them or they just aren't quite exactly what I want for my projects. I decided rather than wasting $100 or more on a set of bars I may not like the dimensions of, I'd build my own from scratch. Below is the cliff-notes version of the build. Hopefully this can give you some guidelines to follow on your own build.
Above you can see the riding position on the bike with the original handlebars and the custom seat we made in the last tech series.
I started by taking some 1/2" round steel bar and bending two identical halves into a rough shape that I liked and welding them together in the center. I took dimensions from some other bars that I liked and tweaked them to my liking. I decided that I wanted a pretty aggressive drop and a slight sweep forward to get into a sportier riding positon. This concept is the same basic way I'd be building the real bars.
We started with 7/8" DOM tubing for the bars. DOM tubing is a seamless piece of tubing and is the strongest option for making something structural like a set of bars for your bike. DO NOT skimp and try to use thin conduit or anything like that, you're putting yourself and others at risk! We then took a piece of TIG filler wire and recreated the first bend in the tubing we needed from our round bar template. This allowed us to use the filler rod as a guide when we were making the first bend. We marked out the length of material the bend would take up and set the tubing with the starting line at the center point of the bottom roller in the Eastwood Pro Former Tubing Bender. We then pumped and bent the tubing until it was just a little further than the bend we needed on the TIG rod guide to combat the spring-back of the metal when the pressure was relieved.
Once we had our first bend we slide the tubing into the stem and checked to make sure that it had the drop I wanted. Here you can put the tubing back in the bender to tweak it a little further if need be. We then marked out the length and center of the next bend to give us the first half of the bars. Depending how close your next bend is to the first you may need to spin the tubing around and come from the opposite direction as the first bend (just remember which way you want to bend!). At this point you also need to make sure that the tubing is set so that your next bend is parallel to the first bend. If you want some slight forward or backwards rake to the bars you could make this second bend just a little off from parallel, but it's tough to replicate multiple times. Again I bent the tubing to match our guide and we test fit it again to make sure that the we had the shape we were looking for. This is where you can stand back, squint your one eye shut and get an idea of what your bars will look like. Take a break, grab a snack, crack open a drink and get ready for the tricky part of this project next.
This is where it gets tricky and I'll admit I ruined some material and had to start over a couple times. When you begin marking out your next bends they need to be perfect to allow for them to match AND you need to make sure all bends are parallel. With a good measurements, a helper to keep it all straight, and a little bit of luck, you could make a set of bars out of one piece of material. I decided after a couple attempts to make the bars out of 2 separate pieces and then sleeve, and weld them together. This also allowed me to keep my bends as close to the side of the forks as possible since I could trim them to size. I chose to shave down a piece of tubing that slipped inside the 2 pieces we bent and used the MIG 175 to join them with a plug welds, followed by butt welds with the TIG 200 DC . I left a gap so that I could get the TIG torch into the gap and melt the inner sleeve to the bars and also enough room to add filler to make it a seamless joint.
After I had the pieces welded together I test fit them on the bike and marked out where the levers, throttle, and grips would sit. With everything marked out I could cut the extra length off of the bars. For most modern bikes the throttle is all one piece and you can just slip it over the bars and fix it in place. On my bike I needed to cut a seat for the throttle slide to sit in (the little aluminum parts seen in the pics above).
With the bars welded and cut to length, I installed my throttle, grips and levers. The final look is exactly as I wanted and the riding position is how I wanted it. The bars still allow for full turning radius and fit me pretty well, so I'm pretty happy with them. Now that the bike is just about how I want it to look I can button up some mechanical repairs the bike needs and then make a small rear bobbed fender and the bike is ready for the road! Stay tuned, I'll show you how to build a simple rear fender for your bobber or cafe racer from scratch with Eastwood Tools next!