BMW windshield rubber well-nuts

[Dr. Strangelove]

I thought about doing the same thing a while ago, but realized that it would defeat the safety engineered into the shield mounting system. If the shield is too firmly attached and you hit an immovable object that jettisons you headlong over the handlebars, the shield might not give away from the mounting brackets and break off to become a scythe to your torso, thus turning an otherwise painful event into a lethal one. Just something to consider.

Hey, Rich, (no flame intended )
I have heard this argument before and have a couple of observations. The "Tall" screen 380 is completely bolted in, so if the "safety" and give way argument is valid at all, why haven't the engineers at BMW applied it to the next lower screen?
It would seem that in the event of a get off, that the touring screen gives way may be a blessing and a curse. It will be fine if your ultimate resting spot is a great big pile of soft hay, but if it is another vehicle or an abuttment I would think that the safety "afforded" by the wellnut design is worthless. It might be better for that big sheet of flexible plastic to slow you down a bit or divert your trajectory, risking the scythe effect, rather than give way so that your hurtling form can make ultimate contact with something really hard without any hindrance from the boys in Munich and as efficiently as Teutonically possible.
Finally, it must be that some brackets hold better than others, but when I had mine, more than once I looked down to see the wellnut making no contact at all with the well(read, flopping in the wind), but quite attached to the screen. I had the pleasure of watching my touring windscreen buffet and wobble in the wind. Seeing 25% of the securing mechanism fail so miserably, I waited for the rest to go and that give-way screen fly up at me. That gave me pause, at least. Seeing its failure was so infuriating that I just cannot buy that they were doing us a favor desinging it so. I replaced it before anything else and never looked back.

It is just too big a surface area to be held by something so weak. Bad design imo. A design that might work is bolts at the bottom and the wellnuts at the top. The ones at the bottom suffer the most stress and if there is anything to the safety argument, it's the ones at the top that you want to give. Just sayin'

John

[Sunbeemer]

All good points John, a screen flying off in your face could certainly cause a bad situation. I also had a wellnut (upper right) come loose from my tall BMW screen. I believed the problem was that the well nuts were not deep enough, so bought some 1/4" longer ones at Home Depot and the longer bolts to go with them. The other thing I learned was that the wellnut gripping surface and the inside of the brackets' holes must be meticulously cleaned - I used Isopropyl alcohol on Q-tips in them - to get the best friction fit. And last, but not least, overtightening the wellnut's bolts draws them up too short. I can't estimate the amount of torque I finally applied, but by visualizing how much the wellnut was being compressed as I screwed in the bolts, I secured them. Haven't lost any wellnuts since (3 years?)

Turned out the real reason I lost that wellnut was because the upper right mounting bracket was loose at the handlebar

The ones at the bottom suffer the most stress and if there is anything to the safety argument, it's the ones at the top that you want to give.

That's true too, so fortunately the bottom wellnuts are mounted at such an angle that much of the stress on them from wind pressure on the shield is shearing (as opposed to trying to pull them out of their sockets).

[Dr. Strangelove]

you must have had a typo. The tall screen 380 has through bolts that screw into the bracket. And I tried all of those tricks to maintain friction to hold them in and they still failed. In frustration I tried contact cement also--do not try this. It doesn't work.

maybe I had a lemon or was just unlucky?? But I had enough.

J

[Xdot]

For those who have to have the exact BMW part: http://cgi.ebay.com/ebaymotors/BMW-R115 ... 500wt_1182