Boxerworks.com

I recently installed a Motogadget Mo-unit Blue and rewired the old bike. I have also replaced the headlight bucket and supports with new 3D printed parts.

It’s very good to be back on the road after 21 months. We had an ‘off’ on a muddy road back in March 2020 which mashed up the previous printed headlight bucket.

I had already decided to replace the wiring next time the bike was off the road and the Covid lockdowns provided a good opportunity. I had been working on plans to move a lot of the electrical components to the space under the tank where the master cylinder had previously lurked (and leaked) since the headlight bucket was completely full of wires and relays and accessory connections, etc. An ugly, embarrassing mess is probably the best description.

Firstly, I am loving the Mo-Unit Blue. Its tiny package provides 10 programmable digital relay outputs. If you haven’t encountered it here’s a link to a YouTube video that explains what it does: https://www.youtube.com/watch?v=gsSNS91EmxU

I have been fooling around with 3D printing for 5 years or so. I bought an entry level printer, made a few mods and housed it in a temperature controlled enclosure so I could print ABS plastic. I also bought a 3D modelling program called “Moment of Inspiration” (moi3d.com), which has proven to be ideal for the organic shapes I wanted to model and print:

The bucket and ears are based on the /5 but sized to take a common 7 inch semi-sealed H4 headlight with a very inexpensive chrome ring from a CJ750 (Chinese copy of the Russian copy of a primitive BMW). I have angled the speedo back a bit so it actually faces my face, to make it more readable. The speedo is a Speedhut GPS model, with electronic tacho.

More to follow ...

I mounted the Mo-Unit on a printed bracket inside the bucket. Yes, there is some more tidying to do but it is so much better than the previous rat’s nest.

And here’s the wiring diagram. It’s a hi-res image, so if you are interested you can save it to your computer and zoom right in. I did my best to match the original wiring colours.

The control inputs to the Mo-Unit are low voltage momentary connections to ground. I was not keen to pay the prices that Motogadget and other companies were asking for the right kind of buttons, and they would have been difficult to fit with the BMW perches. So, some more modelling and printing was required. I managed to design switch housings for the momentary buttons that fit into the original mounts.

The red button on top of the clutch perch is for Ignition On, Start, Kill (double click) and Ignition Off (double click). The blue button is for High Beam flash (short press), High Beam toggle (longer press) and Lights Off (two second press). The orange button is for the horn. On the right are the turn buttons. A short press flashes the selected turn signal 3 times for lane changing and a longer press flashes the turn signal for whatever you have selected in the menu. In my case I’ve chosen to have the turn signal turn off after 10 seconds. There are many options, including turning off after a chosen distance. This feature is a potential life saver – I lost a friend back in the 60s after a car pulled out thinking he was turning. O, and pressing both turn signal buttons turns on the hazard signal.

There’ll be more …

Nice job Airbear! REALLY nice!
Just figuring out the many switch functions could take the average person a few hours.

My bike also has so many wiring mods that now I'm the only one that can trouble-shoot or fix something in a timely manner.

It's a great feeling isn't it?

edit: The main virtue our bikes extoll is that regardless of the mods, we have the possibility to hot-wire our way out of any malfunction.
This is no longer an viable option on modern computer bikes.

Thanks, Steve and GSPD for the comments. Yes, it’s a lot of fun to bend this old bike to my will and drag it into the current century without too much kicking and screaming. Grin.

Re your edit, GS (and note to self), I have yet to figure out what extra wires I’ll need to carry to hot-wire the bike if the Mo-Unit fails. The bike is almost entirely used for rural touring and camping, so I needn’t fuss too much about peripherals. Ignition and starting would probably be enough to get home again.

In the wiring map above there are some electrical components indicated as being in “Box near battery”. There’s a Merit socket (always hot, so I can power or charge devices at a campsite), a voltmeter with a momentary-on button (to monitor the available voltage) and the ignition switch, for when I choose to not operate the bike via my phone (more later on this).

To house these components I modelled and printed a box that attaches to the port-side air-box housing where the ‘choke’ lever once lurked:

There are more 3D printed boxes and brackets under the tank where a lot of terminal connections are located:

Some background information: Brunhilde came into my care 19 years ago as a basically stock example with 153k kms on the clock. A few months later we had a midnight collision with a black cow, resulting in significant damage to the bike, the cow and myself. The forks were bent, the original small tank had a knee-shaped dent, the handlebar was bent to the point where the front wheel could not point forward, and the front mudguard, headlight and instruments were totally trashed. The VIN plate on the steering head was even scraped off by the headlight, and I had to go back to the accident scene to find it. So the bike was no longer a stock example, but hey, what an opportunity to start modifying! The cow died the following day and I had my left shoulder rebuilt with aftermarket parts.

Since that time she’s worn a variety of headlights and instruments, always heading towards the Slash Five aesthetic, since I’m a Slash Five tragic who could only find a Slash Six at the time I had sufficient dollars to consider buying a BMW airhead. Thanks for reading.

To be continued …

Airbear wrote: ↑Tue Mar 15, 2022 10:58 pm Thanks, Steve and GSPD for the comments. Yes, it’s a lot of fun to bend this old bike to my will and drag it into the current century without too much kicking and screaming. Grin.

Wood side panels, current century, makes sense.

Nice work!

gspd wrote: ↑Tue Mar 15, 2022 11:43 pm

Airbear wrote: ↑Tue Mar 15, 2022 10:58 pm Thanks, Steve and GSPD for the comments. Yes, it’s a lot of fun to bend this old bike to my will and drag it into the current century without too much kicking and screaming. Grin.

Wood side panels, current century, makes sense.

Ah now, that wood was milled from a WW2 Oz Army tent pole, manufactured back when BMW riders were discovering the joys of travelling to far flung places by motorcycle to meet new people and kill them.

It is a north American softwood similar to spruce, and after 80 years is very light weight and strong. Brunhilde’s rear rack is made from the same wood.

And I used the same stuff to make the mast, spars and oars for a boat I built 30 years ago:


I’ve always felt that the OEM side panels were a disappointing attempt at a “cover-up”. They seem to be aimed at hiding the fact that BMWs carry a big, sensible battery but in the process they hide a nicely curved frame member that should be seen and celebrated.

Anyway, moving along.

The Mo.Ride app.

Setting up the programmable output options in previous versions of the gadget (then known as the M.Unit) involved pressing handlebar control buttons to cycle through complicated menus. This new device comes with a free app connected via encrypted Bluetooth to the device. Things like how you want the brake light to modulate or the alarm system to react are all selectable through menus on your smartphone. All settings are saved to the “cloud”.

With Bluetooth enabled and the Mo.Ride app running, walking up to the bike is pretty cute. The turn signals greet you by fading in and out in an almost seductive way. Pressing the Start button turns on the ignition and a pleasant female voice announces “Mo Ride ready” on your phone.

The same voice will also tell you if there are any problems with the electrical system. An initial 'teething' problem was that my brake light had an intermittent open circuit issue. That pleasant voice announced "Defect, brake light" and a few minutes later it was traced and fixed.

Press the Start button again and the engine starts (gods willing) and the headlight low beam turns on (if that option has been chosen). The Mo.Ride app will then record your journey. It will produce a map, count the number of curves negotiated, speed achieved and altitude reached and will offer a comment on what sort of riding you managed. My riding is usually assessed as “Lazy” or “Careful”. I haven’t seen the other options yet. O, and if you are visiting your drug dealer or a favourite mistress you can simply turn off Bluetooth and nothing will be recorded.


The gadget includes an accelerometer for the alarm and curve counting. A nice safety feature is that if the bike decelerates sufficiently quickly the brake light will flash regardless of whether either brake is used.

The app also includes a maintenance scheduling system which I have yet to set up.

There could be more …

Beautifull work Charlie, I am really impressed with the new electronics and the woodwork. Having a way to make plastic parts is clearly a plus in your conversions, solves issues with a very nice design. Brunhilde is looking pretty elegant.

cheers

Airbear wrote: ↑Sat Mar 19, 2022 9:22 pm I’ve always felt that the OEM side panels were a disappointing attempt at a “cover-up”. They seem to be aimed at hiding the fact that BMWs carry a big, sensible battery but in the process they hide a nicely curved frame member that should be seen and celebrated.

OK, you got me. Although I haven't seen what they look like directly from either side (pics please), your side covers do 'integrate' better than the BMW ones, aesthetically and organically speaking.
Taking into account your electrical prowess, you should take the aesthetics a step further.
Next time you're bored, figure a way to hide that main (not nicely curved) ground wire . It contrasts with the frame curve you are proud of emphasizing and detracts from your hand-crafted side cover. I routed mine over the top, in through the starter cover, and grounded it directly to the engine block case via a starter mounting bolt. That keeps it out of sight and also provides a (theoretically) better electrical path. If that's too much trouble, at least reposition it so it sort of follows the frame curve a bit.

Questions for Airbear...
1- Why do you need a transmission speed sensor circuit with a GPS speedometer?
2- What's sticking out of your speedo cable hole?
3- I don't see a clutch switch in your left bar wiring and the neutral switch only seems to trigger the neutral light.
Is the Mo-unit smart enough to prevent the bike from starting in gear unless the clutch is disengaged?