Thought the following would be of interested to those riding airhead BMWs

Begin included message #1 - This was from me to Rick Jones at Motorrad Elektrik over the weekend

Bought some of your solid mounts for my '92 R100 GS/PD a few weeks ago. I finally got around to installing them this weekend.

During the install I had a question about some wear on the teeth on the flywheel that caused me to call my trusty local BMW shop. During the conversation I mentioned that I was into the starter area to remove the rubber mounts and replace them with your product.  Their immediate reaction was "WHOA! don't do that. BMW used solid mounts for a while in the '70s and found that the vibration killed the diode boards. That's why they went with rubber isolated ones." Further, they said that your product might cause damage by heat expansion of aluminum cracking the diode board mount holes.

Also, during disassembly I discovered that the upper left rubber mount is already broken and thus must be replaced no matter what.

Now I'm quite concerned. I'm sure you wouldn't sell this product if it were worse than the stock install so I'm hoping for some reassurance from you.

Have you ever heard (and I assume you would if it was a problem) of your solid mounts causing cracking of the diode board because of heat expansion of the aluminum heat sinks?

Have you any experience with whether your mounts cause vibration failures so that I should go back to rubber and simply install a better grounding harness?

I've currently got the bike disassembled. I'm worried about installing your product but must wait to go to the shop on Monday to get new rubber ones if that's the route I should go.

Though it is a weekend, I'd greatly appreciated hearing from you if possible.

Included Message #2 - Rick's reply to me.

Hi Brooks!

I have just two words about using solid diode mounts: no worries!

Solidly mounting the diode board to the engine was the way this part was originally designed from the inception of the type 247 boxer. In my 25 years of working on these motorcycles professionally, it has become apparent that a large number of the old /5-6-7 models out there are still running around with the original (Bosch) diode board fitted. The rubber mounts came out first on the R-90S models, which were expected to spend hours at high speeds, and with their relatively short gearing this translated to higher RPM running. Vibration concerns originated here.

Also, BMW saw fit to solidly mount the diode board on ALL R-80GS models from '81-87, after having had rubber mounts on all other models since at least 1978. Why would they go backwards from their "new, improved" rubber mount design? And especially on a smaller displacement engine, with short off-road gearing which insures a higher-revving engine and thus more vibration? I suspect it was because they knew these bikes might spend a lot of time off-road, turning fewer revs which profoundly affects charging on the type 247.

In an attempt to get the best possible charging under these conditions, one would hope to have the best heat dissipation possible from the chassis of the diode board, which is also intended to be a heat sink for getting rid of the heat created as a result of electrical activity through the diodes. The higher the temperature of any electrical device, the lower its efficiency. The only damages to a diode board as a result of vibration that I have ever seen were the result of solder joints actually melting and vibrating the solder out because of the shaking on the rubber mounts. The rubber mounting system insures two things that increase heat problems: Poor grounding and no heat dissipation from the chassis. The external ground wires used by the factory are, and always have been, inadequate. Even the "updated" ground harness that attaches to the main crankcase casting is still deficient, as evidenced by their chronically "cooked" condition. The rubber mounting system also hangs the diode board out in the air, which is a very efficient insulator. With no air circulation under the front cover, as was designed into the round air cleaner models, the diode board has NO ability to dissipate the heat from electrical activity and from high resistance path, poor grounds. I, too have seen plenty of diode boards with cracking of the phenolic material which is used in the construction of the diode boards. However, it is NOT from thermal expansion issues, but from extreme, chronic overheating of the diode board, especially from the two upper mounting holes where the two inadequate ground wires attach. This chronic overheating explains why the upper two rubber mounts fail very frequently, while the lower two will rarely be found failed.

Ultimately, the proof is in the performance. In over two years of sales of my mounting kit, I have had not one complaint or report of failure from my very satisfied customers. Typically, feedback has been nothing but positive, with typical reports of better charging than before the mounts were fitted. Please forgive my lengthy dissertation, but I feel compelled to defend what I know to be a good product in the face of misinformation.

I'm not an engineer, but I have been making a living working on these machines for a long time, and I know what I see. Thanks again for your purchase, and please let me know if I can be of further help.

Cheers, Rick Jones

Rick's reply was quick and to the point. This is the sort of great service we have a right to expect and I'd encourage you to support Rick's outfit. (Motorrad Elektrik)

by Gene Pori

While having a bit’ of dinner and a glass of wine with our webmaster, the conversation turned to the finer points of tightening bolts, bruised knuckles and the use of the infamous tool, the torque wrench. As he has written a excellent piece on the need for the use of this tool, we got into a spirited discussion of the art of wrenching. Seems that not all is as straightforward as one would like in this business of putting a nut on a bolt, or a bolt in a hole. As a senior citizen. (old mechanic) it seems just yesterday when no old timer would believe a torque wrench …" seen them show it was fight and the bolt wasn't even touching the head" was the story one would hear, when he showed the crew his shiny new torque wrench!

Well. the wrench was not to blame, but rather it was the lack of knowledge about thread lubricants for different materials, lack of information on gasket materials, and carelessness about thread damage and dirt.

These days there are tons of information on all these items. Look no further than your shop manual for your motorcycle. Notice that many BMW bolts are installed dry (without any lubricant). Also many cannot be reused. On the other hand, many Japanese manufacturers require a light coat of motor oil but they never mention what viscosity … maybe it doesn’t matter? They do indicate when to use thread locker (liquid) and what strength when you go to reassemble those pieces that you paid so much for.

There are several steps to reusing existing bolts and nuts that should be done before reinstalling with a torque wrench.

a.. Remember to check to see that the threaded holes are clean. b.. If you ran a tap down a blind hole did you forgot to remove the material stuck at the bottom? c.. Did you run a tap into all threaded holes to clean the die threads? d.. Did you run a die over the bolts? If you leave out anyone of the above, you can forget about using a torque wrench to accurately lighten bolts!

Best practice is to use new bolts and nuts on any critical part such as brakes and steering. Follow the manufacturer's recommendations as to thread lube, grades of replacement bolts and nuts, and washers.

Did I say washers? Be very careful about adding or replacing washers under bolt heads and other fasteners (brake and fuel line banjo fittings) as the use of the wrong washer will also make a torque reading meaningless. (Yes Virginia, there are "metric" washers that although a bit loose are not interchangeable with American SAE sizes).

Sparkplugs … lovely little beasts, last forever now, have you tired to remove a sparkplug in an aluminum head that did not have anti-seize applied to it when installed? Great fun replacing threads in heads. Also check the torque after a few hours of run time (cold) it may surprise you.

Wheel lug nuts and bolts. Check them also after running a bit.

Marking fasteners. One last item. as you assemble that jewel, mark the fasteners as you do the final tightening. Some fingernail polish works well. Use different colors each time. It saves the . "what did I forget" syndrome from haunting you at lOOmph!

Gene Pori

Gene's advice seems pretty solid. You could add that any boltings not using a Nylock Nut gets either anti-seize or blue threadlock. For the few fittings requiring red (Permanent type) threadlock, buy what you need for that assembly then throw the remainder away so you don't accidentally use it where it doesn't belong.