R75 Toaster, Just got, electric jacket, will it work on toaster

Hey every one, heard that R75/5 and early bikes as these airheads, do not have enough output to keep you TOASTY.
What say any one,

Are they Gerbing Friendly and if not, how to fix them..
Scranton, PA Rider

I'm sure there's more on the forum:

https://forums.bmwmoa.org/showthread.php?93762-Newbie-with-electrical-upgrade-question-for-1972-75-5

I think you'll find that it will work but only for a bit. You might need to include a controller or learn to turn it on/off at intervals. Depending on current draw, it's a marginal possibility. Heated gloves/socks are one thing, but a jacket?? Tough...

There are modifications you can do to lower the load on the charging system. LED bulbs for one. A good voltmeter so you can keep an eye on the charging situation wouldn't hurt. If the system voltage is 14 - 14.5 volts it will be charging. You can put on you heated jacket and make sure while cruising the voltage stays up and you should be fine. If the voltage drops below 14, turn down that jacket. I assume you have a controller for the jacket so you can adjust the power?

One can use 12 volt electric heated gear on an airhead, but some user actions may be necessary for management of the load. On my /6 and /7 I would only turn the heated gear on when I was underway and the engine was operating around 4,000 or higher rpm. At stoplights or slow speeds where lower engine rpms are used, I turned the heated gear off.

Use of a variable output controller can reduce the current draw and help manage your comfort level. The more modern variable controllers don't use a potentiometer (rheostat) to control temperature, rather PWM (pulse width modulation) is used. PWM controllers have a wide range in price. An example of a set well built PWM controllers are available from Warm and Safe (link follows). One can have a single knob controller (for both the jacket liner and gloves) or dual knob (dual controllers) that allow independent settings for jacket and gloves. One can get hardwired controllers or others that have a "remote control" feature.

https://www.warmnsafe.com/collections/heat-troller

The same type of PWM control can be accomplished using LED dimmers. Following are some that show 8A capability and are three for $10 -

https://www.amazon.com/gp/product/B073R7H52B/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

One could upgrade the airhead charging system, but this is more expensive and requires some mechanical expertise for installation of the upgraded system. The primary systems with which I am familiar come from Motorrad Elektrik and EME. I have heard good things about both systems.

http://www.motoelekt.com/charging.htm

https://www.euromotoelectrics.com/product-p/edl450-altkit.htm

I think the question is how many extra amps does your R 75 have to burn, so to speak?
On my 1978 R80 I use a Tourmaster heated jacket liner and I've never done the calculations, as in what does my bike put out, how much does it need to run and how many extra amps I've got to use, but my charging system seems to keep up just fine, even on max temp.
When it is on max temp the jacket liner actually gets hot, real hot.
I keep a up to date battery in it too.
And before I plan on shutting the bike off for fuel or the day I turn the heat controller off for a few minutes to make sure the battery gets a top off charge.
Not bad electrical performance for a 41 year old machine if you ask me.

I will bet you the cost of a slice of coconut pie at Edna's in Chatsworth, Ga, that Rick Jones at Motorrad Elektrik can fix you right up. Call him and talk!!! Then you will be HOT and toasty....God bless....Dennis

DennisDarrow said:

I will bet you the cost of a slice of coconut pie at Edna's in Chatsworth, Ga, that Rick Jones at Motorrad Elektrik can fix you right up. Call him and talk!!! Then you will be HOT and toasty....God bless....Dennis

Click to expand...

If it ain't raining too hard at this year's Ga Mtn Rally, I might have to ride over to Chatsworth and try some of that pie.

One other thing that can be done to free up some watts is to use LED bulbs rather than incandescent. I did this and had a 20W headlamp bulb (rather than the 55W incandescent bulb) and two 10W aux lights; thus, I was still 15 W ahead. The LED lights
are typically brighter, but may be less focused than the incandescent light (has to do with the foci of a parabola). I don't usually ride at night so this wasn't an issue. For the /6 and /7 the swap of H4 bulbs was easy. As I recall the /5 is somewhat
different. I believe that it is still possible to use an LED bulb in a /5, but may require a change to the reflector. One could call either Rick Jones at Motorrad Elektrik or the folks at Re-Psycle BMW for more info.

After re-reading this thread i think, without spending any money or real effort, the OP could run the calculations on what his bike should be putting out, and how many extra amps he needs to run his jacket.
If it ain't broke don't fix it is my mantra.

I know this makes Paul Glaves eyes roll but I still run points, tubes and the original charging system on my 1978 R80. It's a period time machine. Back to simpler times.
Purrs like a kitten BTW!

The /5 alternators only put out 180 watts IIRC; the /6 &/7 bikes had 240-280 watt systems. LEDs, or not, there’s not likely to be much juice for a full heated jacket that’s drawing 80-100+ watts, and have enough left for spark plugs, lights, turn signals, starter, etc.

I haven't seen a jacket that runs over 90 watts, and unless you ride in sub 30F you will never run it on high constantly any way. If you are that cold, pull your rain gear on over the top, layer up over the top of your heated jacket. I agree the bike might not handle it on full on, but you can adjust your clothing to help.

In Nov 2010, Matt Parkhouse offered insight into a charging system upgrade with the Omega and Enduralast systems. In April 2019, Matt wrote about an upgrade by EME. In August 2003, he had a general article on electrical system upgrades. I thought he had something on how to convert an early /5 to the later alternator version. Not sure exactly what that entails, but probably the rotor and stator. Some concern needs to be for the shape of the front of the crankshaft...I don't remember if the angle of the taper was different over time.

I did the early /6 alternator upgrade to both of my /5 bikes a number of years ago. No problems and a marked upgrade in available amps.