Sounds great John!

Only one thing I noticed - the rubber mounts should be tossed and replaced with solid aluminum ones. Originally the diode board was solid mounted directly to the engine. The rubber ones arrived somewhere on the scene in an attempt to reduce diode board failures. However, turns out that failures then went up - the board needs the heat dissipation more than the vibration reduction. And I think a higher output board needs it even more than the original.

I thought I needed the ally mounts for my G/S - but turns out that for some reason mine has the orginal solid mount system. So I just happen to have a spare set of ally mounts (stil in the bag with instructions) from I think Motorrad Elektrik... US$20 including post if you can wait till mid-April. Sorry if that sounds like a sales pitch to get rid of some old crap...

Grant

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

Hey, I didn't know that about the solid aluminium mounts, in fact there's a reminder about changing these for new ones in the back of the Moto-Bins catalogue. Still, heh, serve me right for buying the uprated alternator from Motor Works! Oh, come to think of it, M.Bins don't do the 400watt ones anyway.

Actually, one of the things that impressed me about the new diode board was that the power diodes were mounted on individual, proper, heat-sinks, so they will be better cooled, though, admittedly, as they are handling a greater current, they will need better cooling anyway.

In my previous musings regarding increasing the output of the original 280watt BMW alternator I had considered providing better cooling for the alternator, the existing provision for cooling is pretty minimal, there's only the two little vents at each side at the bottom of the chain case at the front of the engine. The power produced (or dissipated) in any electrical item is generally limited by its temperature; the hotter it gets then the more likely the insulation is to break down; if you want more output, then cool it some more. So, what I thought was, drill a hole at the top of the front cover and put a little vent cover on it to keep the rain out, perhaps like the vent plug on the bevel drive casing, but a bit bigger.

Going back to the solid mounts, they would be better for another reason, too. I found it difficult to tighten the earthing straps tight under the flexible mounts as it was not possible to grip the mounts while tightening the nut. As it turned out, however, it wasn't necessary to hold them as they didn't want to turn anyway. Hmm, some you win... Anyway, I did do this before actually putting the board in position because of the expected difficulty, and then put the board in its place on the chain casing and fitting the other nuts . (I keep on calling this the chain case-that is its name, isn't it??)

I did take some measurements of the new kit before fitting it to compare with the original.

The rotor resistance is the same at 3.5ohms, the slip ring diameter about a millimetre greater, the body diameter a couple of millimetres (I've got the actual measurements somewhere, but the difference is not really significant) There are no balancing drillings visible, unlike on the original.

The stator is again the same dimensions practically, but the air gap is about a millimetre smaller which is probably significant. The conductor diameter is up from 0.045ins to 0.055ins, sorry, hang on a minute, that's 1.143mm to 1.4mm and is wound differently, the new one being wound approx eight??? turns around three poles and then on to the next three poles and so on, and the same for each phase with each phase being one pole further on. One end of each phase winding is commoned and brought out as the star (Y) connection and the other ends as individual connectors and labelled U,V & W. Total no of poles is 36, no. of laminations 25. Length of pole face is 21.6mm and the gap between 5mm. The old stator was wound with the conductor weaving over three poles and under the next three and so on, again with the three phases with each one pole advanced. My multirange meter was only able to give an approximate reading of the phases, of 0.1ohm for the new and possibly 0.15 ohm for the old. I couldn't count the number of turns on the poles without cutting it up, sod that, the original is still in good working order. I've given all these dimensions in case there's another freak (that's what my daughter calls me, anyway) out there. (Oh, she also calls me a sado. As in sad) Sigh.

Cheers

J

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Johnefyn

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Johnef

Hi, Grant

Just read your last reply again and am worried by your comment re using FOUR solid aluminium pillars.

This would be absolutely OK with the original type of board but just in case there's somebody out there planning on getting the Motor Works kit then I think I'd better point out that you can use two such pillars for the top pair of mounts but you will need two INSULATED pillars for the bottom pair as the bottom half of the circuit board is live and connected to the battery +ve and MUST therefore to be insulated from earth. No pillars (of either type) are supplied with the kit. For that matter, no instructions are supplied either, but it wasn't too hard to figure out, and to be fair Motor Works did say so when I placed the order. And, yes, it's still working great.

Cheers

J

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Johnefyn

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Johnef

hmmm.... bad design there; mine for instance has ONLY cast one piece solid mounts - NO option to insulate, and no room to add in insulated pillars!

Grant

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

In the original there is an insulated bush provided around the mounting hole on the board whereas there is none in the Motor Works one, only a bare patch of printed circuit conductor. I think I'll let Motor Works know and perhaps they could at least point that out to customers even if they still won't prove full instructions.

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Johnefyn

PS I should add that there would be no problem with the above if you still used the flexible rubber mounts as they would provide the insulation required. One solution would be to use two solid pillars and two rubber mounts, there wouldn't be a lot of weight on the rubbers, but then again they wouldn't last forever. As for me, I'll just leave the four rubber mounts in for now and if I and the bike are still around in ten years' time, I'll do something about it then.

[This message has been edited by John Roberts (edited 30 March 2005).]

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Johnef

The 400W alternatot kit as sold by Motorworks is made by the same company as the kit sold by Rick.

Airhead BMWs have no problems being ridden at low revs. remwmber that Airheads ahave been used by many police services who do escort duty at low speeds and low revs.

Charles

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Charles CCM450, BMW R90/6, BMW R50
http://i46.photobucket.com/albums/f1...a/027_27-1.jpg

Just read this thread as it came up with todays postings. I feel I have to say something in defense of this bike as "the best tourer". I owned one in the mid-80s when I worked as a despatch rider based in Leeds. I was averaging 2000 miles a week and in 2 years covered over 200,000 miles on a 1977 R100RS motosport, with very little down time due to mechanical failures. I frequently did trips of around 1,000 miles in 24 hours when we were delivering advertising copy to newspapers around the country and I have never ridden a bike either before or since which I have found as comfortable over such long distances in one go. Unfortunately by the time I finished my despatch riding the bike had over 220,000 miles on it and needed a complete rebuild so I ended up breaking it for spares. I was so impressed with it that when an identical bike came up for sale a couple of years ago I bought it. 70 mph is around 3,750 rpm and everything seems very much in harmony and comfortable at anything up to 80 mph. It's also quite capable of sitting at over 100mph for hours on end as well, although sadly that's not really possible now. The only criticism I would level at it is the excessive wind noise and buffeting which seems aimed directly at the riders helmet from the screen.

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If you think you are too small to make a difference you have never spent the night with a mosquito.

Wind noise: yes, that's just about the only real grouse I have with the bike. One possible solution is a BMW System 4 (or is it System 5?) or a Schuberth, and then there are earplugs, which I've only come across after decades of riding. I've posted threads on both quiet helmets and earplugs and both attracted a lot of very useful replies, my current solutions are earplugs, the cheapo ones rather than the custom-made ones but that's only because I haven't got off my backside and actually got some made and fitted.

Otherwise, I still think it's a belter.

John

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Johnefyn

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Johnef

Ahem, AFAIK the /5 had a 180W alternator, at least mine did, according to the w/shop manual...

Ahem again: the airhead alternator is mounted on the crank. "Everyone else" are the car makers, who use pulleys to speed them up.

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Cheers,
Peter.

Europe to NZ 2006-10

I debated the whole upgraded charging issue for a few years too. I decided to go with the new kit from http://euromotoelectrics.com/

Here's a link with a write-up from my install: http://tinyurl.com/bncde

Nov 4, 2005

I just returned from a test ride with my R80RT after installing an Enduralast 450 Watt system from http://www.euromotoelectrics.com/enduralast.html

The bottom line is that from about 1200-1300 rpm onwards, the system puts out 14.1 to 14.2 volts. At idle, it’s between 12.4 and 12.6 volts. I installed a Datel volt meter to give me a constant read-out during riding. I puttered through town this evening and briefly hopped on the freeway. At all points the voltage was constant between 14 and 14.2. Yesterday, after ensuring I had rigged everything up correctly, I wired up an electric vest and a 70 Watt power inverter to the battery. Flicking the high beam on and off at idle makes the voltage blip, but it returns a steady number after a second or so. Since the inverter and jacket didn’t seem to make a difference in the voltage readout yesterday, I did not wire them up for the test ride.

The kit contains a rotor (solid magnet) and stator, a mounting bracket, a rectifier and a bewildering array of little wires and connectors, of which you end up using a fraction. There’s even a rotor puller bolt included.

The installation is relatively straightforward, but you do need to read the manual carefully. The wiring diagram is a no-brainer. Since I am going to move this system to my G/S in a few months, I did not bother removing any of the original wiring. Since none of it is needed in the meantime, I taped up all the ends and left them where they were.

Installation:
First job is to remove the original stator, rotor, diode board and voltage regulator. I left the voltage regulator in place courtesy of two spun screws.

Mounting the rotor is the same procedure as a regular one. Since we’re dealing with a solid magnet rotor, you want to make sure your wallet and credit cards are not in the vicinity. I wondered about the Hall sensor with this thing nearby, but a timing light check confirmed nothing had changed.

The stator is mounted between two aluminum brackets and screwed into place with 3 screws in the same location as the original. No brushes here … this is a “contact-less” system. As with the original stator, you need to slowly easy it into place and tighten the screws in turn. There is one big wire going up and out of the front cover cavity, that’s it. The only other wire under the front cover after the install is the wire to the timing can (for post-81 machines). Lots of space to mount a small box with tools where the diode board was… hmm.

I ended up mounting the rectifier to a frame tube and ran a car-size ground wire to the battery negative. This was pure laziness on my part, as others have installed this rectifier under the tank after removing the voltage regulator. It fits in that space.

The wiring is simple: The voltage regulator plug ground and blue wire are used (with spade connectors), a wire (with provided 30 amp fuse) to battery positive. Two plugs connect the rectifier to the stator, one wire connects to a switched positive. For the latter you need to bare a (small) wire that gets “hot” when the ignition is on and splice one in. That’s about it.

I spent most of my time trying to figure out where I wanted to mount the rectifier … the RT has less space than other configurations and I could not remove the voltage regulator. In hindsight, I preferred it that way.

During riding I noticed not much difference, except that my stock voltage regulator was reading much higher than before. It’s nice to know that even when you’re loitering through town you’re not draining the battery. I was somewhat concerned that given the strength of the magnet, there would be more drag on the motor and hence I’d have to adjust idle (more fuel consumption…) but that proved to be unfounded. As well, the rotor weighs less than the stock one. I touched the rectifier at the end of the ride to see if it had heated up, but it was cold.

I’m going to eye-ball this setup for a while and decide whether I want to move this over to the G/S. This whole thing started when I contacted John Rayski (Euromoto Electrics) and quizzed him on whether he wanted to have a “guinea pig” for his new system. He was happy to provide me a system, gratis, for which my thanks. Next April, I’m off for a LONG trip across Europe to China and beyond. In order to eliminate the need for carrying an extra rotor and diode board, as well have better charging, I want to take this setup. Since it’s on the RT, I’ll put ample mileage on it between now and then to provide me with enough comfort to put it on the G/S.

Another (small) benefit of this system is that the charging light, although powered as with a stock setup, is not required to function for charging to take place.


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Kevin

http://www.nohorizons.net

[This message has been edited by kberetta (edited 06 March 2006).]

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http://www.nohorizons.net

Ahem, AFAIK the /5 had a 180W alternator, at least mine did, according to the w/shop manual...

Quote:

Originally posted by Grant Johnson: with the BIGGEST problem overall is the alternator turns at HALF speed 'cause it's on the cam, where everyone else mounts it on the crank

Ahem again: the airhead alternator is mounted on the crank. "Everyone else" are the car makers, who use pulleys to speed them up.

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good catch beddhist!

you're absolutely right on the alternator of the /5 - I was thinking slightly later model (and clearly not that well):

"The /5 alternator output was rated at 180 watts, the /6 at 280 watts, the very slightly smaller diameter rotor of the fast-spinning R90S was rated at 238 watts, and the later models rated at 250 or 280 watts, depending on year."

BUT - "Everyone else" being MOTORCYCLE manufacturers, mostly do mount it on the crank where it turns at double speed compared to the airheads, OR indeed off a pulley, as do car manufacturers for even higher speeds.

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

Grant,

Why do you say that airhead BMW don't like low revs? What breaks and why?

My R75/5 rarely gets above 4500, but often down to 2000, as I cruise through town in top gear at 50 km/h. The engine has done over 100000km without any bottom end work. The barrels got replaced, because it was burning a little oil and I had spare ones lying around. however, if it gets thrashed it throws oil fumes out of the exhaust and the rear of the bike gets covered in oil spots.

My girl friend has two R100 and rides them similarly. Both 100000km. The people who I have met here in Europe who have exploded engines thrashed the bikes. Courier riders come to mind.

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Cheers,
Peter.

Europe to NZ 2006-10

the slightly cheaper option is to get the police spec voltage regulator, which charges the bettery at lower revs, better for trail riding and round town work. hope this hasnt already been mentioned.

And those voltage regulators will boil the battery on long motorway trips - the battery sits at a highter voltage, more heat = boils off water = dry battery = stuffed battery. Be carefull if you fit one of these - check the battery water levels frequently. Like at least once a day if doing constant high engine speeds.

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Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S

I did try one of those a few years back but I must say I didn't find any noticeable difference.
John

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Johnef