Sunday, April 29, 2012

Part 20 - Handlebar mods for Dakota Gauge Cup

Looking purely at fabrication aspects of the bike, the most time consuming fabrication effort was the handlebars. Ok, cut the laughter and read on.

The first modification to the bars consisted of making holes for the internal wiring and adjusting the ID of the right side to fit the internal throttle. This is all explained in the following blog posts

The next step was to install a gauge cup to hold the speedometer/tachometer display. The gauge cup is a good quality item from Dakota Digital. For the first round, I used the $80 mounting bracket from Dakota Digital. The result looked like a minimum effort bolt-on, which is exactly what it is – out of place and dead ugly and it leaves some wiring exposed to connect the gauge. Uggggg!

For round 2, I removed the bracket and made a hole for the wires in the handlebar and tapped a hole for mounting the gauge cup. This allows the gauge control wires to be hidden which solves one aesthetic problem and the gauge sits right on top of the handlebar partially solving the wart-like aesthetic issue with the Dakota Digital bracket.  

Mounting and wire entry holes for more integrated look

Gauge cup mounted directly to the handlebar

All of this sounds straightforward and easy enough to accomplish in 5 minutes, and I guess it should be. But, the amount of time spent staring at options, sourcing brackets, deciding where to drill the hole, deciding whether you really want to take a drill to the expensive chromed gauge cup to modify it for direct handlebar mounting, all takes time. Lots of time. Easily 8 hours of time. 7.5 hours of thinking and research and 1/2hr of actually doing the work. I lived with the results of Round 2 for weeks. Slowly but surely I went from “it’s okay”, to “it will work”, to “its half @*&$@”.  

Time for round 3. Why not invest even more time into a set of handlebars. It’s not like the bike ever needs to be finished, right? Round 3 is the ultimate (for me anyway) aesthetic mounting. I had seen this style of mounting on a Jerry Covington bike and thought that if I ever developed the skills, then that is what I wanted for my bike. Turns out, Dakota Digital make a raw steel gauge cup that can be welded in place. The only problem is that the handlebars need to be chopped, a piece big enough to accommodate the gauge cup removed, the sides coped to match the gauge cup profile (which isn’t easy), gauge cup angled correct for the rider and then everything welded in place. All this has to be done making sure the handlebars are still straight and above all safe when the job is complete since the gauge cup will now be holding the handlebars together. All the cutting and shaping was done with a dremel tool, hacksaw and hand files. 

Handlebars clamped to ensure alignment

Dakota Digital Steel Gauge Cup - hole drilled for wire entry

After  4 hours of labor the mounting was done. Aesthetically, hands down a winner. The cup was welded in place with the flux wire welder. Some of the ugliest welding you will ever see but I’m pretty handy with a grinder. Grinding and welding, or is that welding and then grinding, easily took an extra hour so we were up to 5 hours.

Gauge cup welded in place

Then I made a fatal error. I was pretty proud of the look I had accomplished and pleased that I persisted past the very basic bolt-on from Round 1, through the more integrated Round 2 and the ultimate Round 3, so I called my wife to take a look. First comment “why is the gauge pointed up at the ceiling” so I remind her that it is made for a taller person. Ok, onto comment number 2 – “something doesn’t feel right”. “Wadaja mean” I ask? “Feel right? That is not an engineering term”. “Is the gauge in the middle?” she asks. Ok now we have some more technical terminology so this is easier to deal with and I explain with great pride how often I measured and how much effort I took to ensure that the cup was perfectly centered between the risers. The response – “well something is off”. Mmm not an engineering term but maybe I’ll send the wife on back inside while I work on some more technically challenging issues. The handlebars look great – in my opinion. Maybe the welding and grinding and lack of paint are “off”. Then she says “the left looks longer than the right”. “Yes ma’m, there is a 4 inch difference to allow for the internal throttle” I say demonstrating my technical superiority and easily refuting the “its off” statement. Expecting that to be the end of it, I moved away to clean up the tools. She drops the next bomb shell – “If you look carefully you’ll notice that the bend on the right of the handlebars starts a little closer to the speedo than the bend on the left”.  Still feeling pretty sure of myself I take a look. Wham. Hits me in the head. The damn handlebars are off. Now I’m using inappropriate technical terminology but it works for this situation. Out come all manner of measuring devices and yes, the handlebars are longer on the left than the right by easily ¼” when measured from the outside of the riser to the edge of the thick bar as illustrated below.

I had been so fixated on the gauge cup centering between the risers, I never noticed the handlebars were badly manufactured. I tried as I could to look past this not wanting to lose the time investment, but hell, there was no way that this was going to fly.
Emailed the vendor and told him what had transpired. At this point he is suspicious because I had modified the handlebars and he is sure (although not coming right out and saying it!) I screwed something up so he asks for me to send them back. Easier said than done my friend. Eventually we discuss by phone and I agree to send them back but needed to recover the expensive gauge cup first. More grinding and whining and eventually after many hours of careful grinding and not so careful whining I am able to extract the cup. Ship the two halves back and get the confirmation that “yip – bars are off”. At least I now know that “off” is acceptable bike builder terminology.  He further confirms that the batch of 6 he has in stock are all “off”. Someone must have messed with the jigs used during manufacture. Eventually the replacement arrives. It is back to square one.
All the work done on the first handlebars had to be repeated. I’d like to say it went quicker the second time because I knew exactly what I wanted to do but all the modifications wound up taking 8 hours at least. The gauge cup install was as much of a bear the second time as the first time.

Fast forward about 3 months and the bike is being prepped for paint. After a lot of work with body putty molding the cup into the frame making it look a single organic piece, it is time to shoot the primer. Primer goes on and the bars look great. So why stop there? Why indeed. Here’s a great looking handlebar but the wire exits between the risers leave a small amount of the wire harness visible. And how safe is this whole business of a gauge cup keeping the 2 halves of the handlebars together? Mmmm, given that the gauge cup had to be welded and then extracted and then re-welded, what is the integrity of the metal? Mmmm. Maybe I need to add some reinforcement. Mmmm, if I add reinforcement that can double as a wire hider - that would be helpful.

Round 5 - So after a little more thought, out comes the grinder, some ¼” steel plate, a piece of old 16 gauge sheet metal. After making the new parts and grinding off all the primer I had just put on, I had another 3 hours invested into the handlebars. Then it was off to Ron’s house to use his TIG welder to weld the new parts thinking that 1 hour would be all I needed. Things went downhill fast. Having experienced all manner of metal distortion using the TIG welder, I was prepared for anything and started with the handlebars bolted to the top clamp of the triple trees to make sure everything stayed in position. After a lot of fussing, the plates are tacked in place - everything is square and beautiful. I unbolted the handlebars from the clamp and noticed that the bolts where now a little tighter but figured that the metal had moved as far as it was going to move and the tacks would hold everything in place during final welding. So I commence with final welding. 

"Final" Welding
At one point I heard a metallic “plink” sound but thought nothing of it. Had I stopped at that point and investigated, I would have discovered that one of the tack welds had broken due to the welding stress allowing the risers to move in toward each other. But I didn’t stop and inspect and completed the welds on both sides. After things had cooled a bit, I test fit the bars to the triple tree clamp and THEY NO LONGER FIT. The spacing had shrunk by a full 3/32” so it was no longer possible to bolt them up. What a mess. Ron reached over and shoved the grinder in my general direction with a “I think you’ll need this....” expression on his face.
Damn, all the work down the tubes. After another ½ hour of careful grinding and I had the one end of the front and back plates loose. Even though the risers sprang back when the final weld was released, there was still an offset between the riser spacing and the clamp. Something had bent in the process of welding everything together. At this point there was nothing else to do but grab a big crowbar and start bending things back to normal. With Ron manning the crowbar and me the welder, we managed to separate the risers enough and tack the plates back in place with heavy duty tacks this time. According to Ron, he could feel the risers pushing back on the crowbar during the first tack weld but I’m not sure that this was the beer talking. Eventually, everything was welded up and everything fit. Another 4 hour mission complete.
It would be great if the story ended here..... but it doesn’t. The wire entry hole in the top triple clamp is not centered front-to-back between the risers - the hole is slightly forward of the obvious place to put it so I had to cut a slot in the front plate and then weld a cosmetic piece over that to properly hide the hole in the triple clamp. in the middle of the bars. Another session of grinding everything smooth and some more body putty to re-create the organic just-grew-out-of-the-metal look. 

Finally, reprimer and repaint. Surely that is the end of the story but no. I got a pretty major paint run which required some serious sanding to remove. In the process I sanded right through the paint, which required more work to repair. The good news is that I think I’m finally done with the handlebars.... Seriously.