During the Jungfrau Treffen I had an interesting discussion with R1NGA about the bevel-box problems.
During this discussion I got an idea which I told R1NGA about. He crabbed his head and said: "Hmmmm, perhaps your correct".
Let me explain my thinking
Many times I wrote that the bevel-box of a BMW motorcycle make almost no noise. Is this a different construction or it it something else ?
Let's compare the two bevel-boxes.
The rear wheel of a BMW motorcycle is directly coupled to the big crownwheel in this bevelbox.
So if the rear wheel makes one turn the crownwheel also makes one turn.
Let's assume the rear wheel tyre has a circumference of 2 meter. When driving 100 kilometer per hour the wheel rotates 14 times a second.
So also does the crown-wheel in the bevelbox of the BMW.
With our M3W the front sprocket of the final drive belt is coupled to the crownwheel.
When the rear wheel rotates once the front sprocket (and the crownwheel) rotating 2 times (due to the difference in size of the final drive belt sprockets)
So instead of rotating 14times a second like the motorcycle crownwheel
our M3W crownwheel need to rotate 28 times !
So our M3W bevel boxes need to rotate double as fast at the same road speed compared to the BMW motorcycle or any other motorcycle with a bevelbox.
Can this perhaps be the cause (or one of the causes) of the problems with the screaming bevelboxes ??
Last edited by Laurens; 11/09/17 08:23 AM.
