Custom Triumph Bonneville Speedometer Bracket from D9

Installing a D9 custom speedometer bracket on the Motorcycle Classics/Dairyland Cycle Insurance Triumph Bonneville

Bonneville Build

Almost Done: The Motorcycle Classics/Dairyland Cycle Insurance Bonneville Build at Road America Vintage Motorcycle Classic, June 12, 2010.

Rod Peterson

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As part of our Motorcycle Classics/Dairyland Cycle Insurance Bonneville Build, we knew from the beginning we'd want to do something with our 2010 Triumph Bonneville's stock instrument panel. While the stock setup is perfectly functional if even somewhat minimalist, it’s not minimalist enough for what we’re going for with our bobberized Bonneville. An integral element of our project was/is to alter the Bonneville's tallish stance and morph it into something low and lean. The stock gauge setup sits proud of the handlebars and angles back. That arrangement works fine for the stock Bonneville with its upright riding stance, but it wasn't going to cut it with our bike. Enter Seth Bernstein at D9 Brackets.

Seth, a diehard Triumph fan and a regular at the newbonnevilleriders forum, has designed the D9 range of accessory brackets for modern retro Triumph owners. Available in configurations to support a single speedo or a speedo/tacho combination, Seth’s aluminum, custom-crafted brackets were just the minimalist kit we were looking for. Beautifully crafted, the brackets benefit from Seth’s considerable experience with retro Bonnevilles, and they really let us put the right face on our project. Seth has plenty of options, including a bracket for aftermarket mini-gauges, all of which you can find by clicking here.

We opted for item 03-0748, a simple, satin black "lay flat" bracket with four built-in LED units for turn signals, neutral, oil pressure and high beam. Following Seth’s advice, we substituted a smaller trip odometer knob from a Triumph T100 in place of the stock item used on the speedo-only Bonneville because it looks less obtrusive with the new bracket and housing.

Installing our D9 bracket was easy enough. Although we went a little slower than normal because we were taking pics as we went along, it still only took us about 2.5 hours start to finish. Figure 2 hours for the average install, maybe a bit more if you’re really taking your time.

We’ll provide photos of our finished bike when it’s all done, but you can get a taste of what it took to install our D9 bracket by clicking on the “Image Gallery” link and following the captioned photos we’ve posted. One note of apology: Try as I might, I’m still finding I don’t always get every picture that I should. If there’s any step of the project you don’t understand, just post a comment and I’ll answer here. – Richard Backus 

UPDATE: We discovered once we got everything wired up and working that, well, it wasn't all working! To wit, our turn signals were a no-show. At first, we figured we'd just done something wrong and that we'd sort it out easily enough. At the same time we installed the D9 bracket, we also installed a set of Joker Machine's way cool Astro LED turn signals. As we've since discovered, the LED turn signals require a pair of diodes to keep the current flowing separately to the left and right blinkers. The stock wiring has separate input wires, one for left and one for right, running to the turn signal indicator. When using the LED signals and the single LED signal indicator, you MUST wire in a pair of diodes, otherwise when you operate the turn signals for one direction, power will double back to the opposing signals and all four will flash. The diodes act like a one-way valve, allowing current to flow through in one direction only. The fix is to simply solder a diode to each turn signal indicator input wire, then twist the diode output lines together and solder them to the PINK lead wire that runs to the LED indicator light. The BLACK wire from the indicator lamp is then run to ground. We simply spliced it into the stock BROWN/BLACK-DASHED ground line (there are three, they all join together a few inches down the line). Result? Our blinkers were perfectly, thank you very much. We got our diodes from Radio Shack, stock item 276-1114. Check the image gallery for an updated wiring diagram showing the diodes wired in. Note that the diodes must be oriented with the small silver band on the diode biased toward the LED indicator, as in the diagram.