Custom Triumph Bonneville Speedometer Bracket from D9

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Almost Done: The Motorcycle Classics/Dairyland Cycle Insurance Bonneville Build at Road America Vintage Motorcycle Classic, June 12, 2010.
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Next, remove the two Phillips screws securing the cover for the warning lights and remove the cover.
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Next, using an 8mm socket or wrench, remove the two nuts that hold the speedo and casing onto the main body and remove the casing.
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Here's the stock 2010 Triumph Bonneville speedo unit. The standard Bonneville comes with a speedo only. While not bad looking, the stock panel is bigger and taller than we wanted for our build.
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Rear casing removed.
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Removing the speedometer unit from the bike is easy. First disconnect the speedo cable (at the wheel or the speedo), then unplug the speedo wiring inside the headlamp shell, followed by removing the four bolts that hold the speedo to the upper steering stem. Once the speedo's off and on a work surface, remove the trip odometer knob using a small Phillips driver, as shown.
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With the cover removed, carefully cut a slit in the wiring harness cover (shown removed at right) and expose the harness.
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Here's the original speedo and instrument panel separated. It's easier to separate the two after cutting the warning light wires as these wires run into the same harness that feeds the speedo.
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With the harness cover removed you'll see that the wires to the warning lights are banded with a numbered code. Record the code number and wire colors and their corresponding light function; you'll use this information later when you connect the new lights from the D9 bracket.
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Next, clip the wires to the warning lights. Leave a bit of a tail on each warning light unit - you might want to use the lights for something else later.
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Now you're ready to start the transfer of parts. Here you see the D9 bracket and the rubber grommet for the speedo. A close look shows a square protrusion molded into the grommet. This aligns with a notch cut into the bracket, visible at 6 o'clock. You'll also note a rounded, half-moon cut in the grommet, which aligns with the odometer trip knob.
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And that's all she wrote! The only thing left to do now is reinstall the finished speedo/bracket assembly onto your bike using the new button-head allen bolts supplied with the kit. Seth at D9 also supplies spacers of varying thickness depending on application needs.
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Place the grommet into the D9 bracket and gently push the speedo into place. Once the speedo's located, turn the unit on its face and place the new speedo shell on the bracket. Wrap the four wires shown (2=brown/black, 2=red/blue) in electrical tape where they pass through the speedo body to keep them from chaffing.
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Follow this wiring diagram if you're also using LED turn signals. They won't work without the diodes wired into the turn signal indicator lamp. Note the orientation of the silver band on the diode; it must be biased to the indicator lamp. We used two of Radio Shack diode part number 276-1114.
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Once all the wires have been soldered, wrap the harness in electrical tape to tidy things up and to protect the wiring harness. Once that's done, place the back plate on the new speedo shell and secure it with the black nuts provided with the bracket kit. This secures the speedo to the D9 bracket
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Working from the notes you made on the wire inputs, solder the LED lights from the D9 bracket to the appropriate wires in the harness. Use heat shrink tubing to protect the solder joints. For the lights, we went like-color to like-color, as in blue for high beam, red for oil pressure, green for neutral. IMPORTANT: Use the yellow/amber LED for the turn signals as it has flashing capability built in. Otherwise you'd have to wire in a diode.
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Compare the previous picture to this one, showing our Bonneville close to finished, and you can see the D9 bracket sits lower and flatter, a perfect match to the low stance we've given our bobberized Bonneville.
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Just in case you were wondering about the speedo trip knob; that's the stock single-speedo Bonneville knob on the left and the smaller T100 knob on the right.
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Here's our Triumph Bonneville early in our project. Note the speedo assembly, which sits fairly high and angles back at the rider.

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.

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