The most dramatic moment of my attempt to ride the 1968 BMW R50/2 home from New Hampshire was when I released the magic smoke from the turn signal flasher. I've been using hand signals to confuse other road users with a statement of my intentions ever since. But now that the bike is running well again, I'd like to get back to the modern method.
Technically all I needed to do was plug in a new flasher unit. I'm pretty sure the short was from the flasher unit falling out of its mount, and not from a random wire “going bad”. But, I wanted to replace the wires that I had wrapped in electrical tape after their insulation had melted off first.
One of those wires led to the handlebar control. If I was going to open up that bundle, I might as well replace the other two wires in it, right?
This was also a good time to replace the wire that likely got stretched when the right hand signal dislodged and flapped in the breeze a bit while I was attempting interstate travel, right?
Another melted wire ran to the headlight (that bare/charcoal one). Other headlight wires leading to the the control on the left grip have never looked great either, so I should replace them too, right?
Before I knew it, I was planning to rewire essentially everything forward of the steering stem. There are only a half dozen more wires leading to the rest of the bike, but I had to put my foot down somewhere.
The rest of the wires were also notable in that they were the only ones whose colors matched the official wiring diagram. There are five red wires in that "before" picture above. There is one red wire in the diagram. So step one was to figure out how my territory compared to the map.
Correcting the mismatched wiring required its own compromise. Almost every wire is specified to be uniquely identifiable. The wire to the right signal is supposed to be blue with a black stripe; the one to the left signal, blue with a red stripe. The high beam is white, low beam is yellow, and the supply to the switch is white with a yellow stripe. Und so weiter. I needed at most half a meter of each of some dozen colorways. I opted instead to use the main color of wire in each case, and add a collar of electrical tape in the stripe color at either end. Remembering this is a problem for future me, and a good reason to write it down here.
Getting to all of the connections required removing the combination circuit-board-and-key-switch rig in the top of the headlight nacelle. If you are ever working on your own R50, I strongly recommend avoiding this activity. The removal isn't too bad - just un-bend some metal tabs, and catch all the spring-loaded things that fall out. “Reinstallation is done in the reverse,” is a threat in this situation. The next time someone posts a picture of some tool they can't identify, I'm going to suggest it's a /2 keyswitch installer. The number of components that need to be aligned while fighting spring pressure means that I am sure both that said tool exists, and also that it is wild-looking.
Once all the new wires had been run, and the key-switch reinstalled, it was finally time to install the new flasher unit! The new one is much larger than the old one - too big for the original mounting bracket. Instead, I zip-tied it to the speedometer bracket. I think this is more secure, but I also used insulated connectors to plug it in, so if it does come loose, it shouldn't cause a short again.
With so many loose-ish wires hanging about, especially once I pulled the key-switch board down, I decided to go longer between tests than I normally would. Thankfully, frequent checks with my multimeter proved to be effective. Everything worked when I finally reconnected the battery.
The system for mounting those bar-end signals is a screw that pulls a wedge-shaped nut into fingers cut in the end of the signal housing. That pushes the fingers against the inside of the handlebars, for a friction fit. Three of the four fingers are missing on the right side. In New Hampshire, we placed a small strip of lead flashing in their place. That's now on the shoulder somewhere along I-190 in Massachusetts. I've used a strip of brass this time. It was much harder to get in place, so I'm hoping it's also much harder to dislodge.
The zip-tie flasher mounting solution also allowed me to try out one of this model's alternative mirror positions. One style of mirrors screwed into the headlight, and extended outward slightly below the level of the handlebars. My cheap generic scooter mirror had the same M8 mounting thread. Its only problem was that the threaded end was too short to also hold the flasher unit's mount on the inside.
The initial install was okay. It provided better visibility than the handlebar mount I had been using, which required me to twist my torso and arch my neck to see anything at all. A couple minutes with a blowtorch and a vise to straighten the bend in its bar, and suddenly the view was great. I rode off to O'Reilly and bought a second - different brand, exactly the same build - and applied the same bend before installing it on the other side.
The mirrors may have been my first major change to the asthetics of the bike. But in rewiring, as well as in replacing control cables, I had also removed a lot of slack in each that was cluttering up the area. The whole frontend looks much tider. (Now if I could only do the same for the workspaces!)
Anyway, since it now feels like I can properly interact with traffic, it's time to go play in it some more!
Categories: Motorcycle
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