At some point Ducati went to a lower frequency on some models due to bearing failures. I don't think Ducati uses 140 for anything at this point.
That´s interesting ....
I went to a track day last friday, my first real ride for this year. The first 2 stints I rode the m800, and after getting used to all the normal noises, I thought I heard one I did not recognize ... If i reved the motor at standstill, I thought there was like a WZZzzzzz.... noise when the revs went down again.
I took off the covers to se if everything seemed OK, which it did, but on the still-warm motor, the belts were quite tight.
When I got home, I did some checking and experimenting with the modified sleeve, now 2.5 mm wall thickness:
20210518_103706 by
torbjörn bergström, on Flickr
It actually is possible to get very different levels of tension on the belt, "tight" can be very differently tight, but snugging up the tensioner against the sleeve, slightly tightening the fulcreum bolt, the using a small hammer and a drift on the movable tensioner bracket to tighten the belt, there is now a slight gap between the fixed roller and the belt with the sleeve removed.
With the Gates app, that translated to somewhere in the 140 Hz range. Measured with the allen key method, that´s tight om the 4 mm ky recommended by Kämna at tthe service course I went to many years ago.
Doing the same procedure again, but sligtly less tight, gave reasonably consistent readings in the 120 Hz range (with occasional readings of 270 Hz, 55 Hz etc, etc, ....), so that´s where I left it for now. Depending on if I hear something or not on the next ride, I might either try even looser belt, or change the bearings (which all felt fine, no rough spots or noice). If there´s a noice, I´ll probably change the bearings anyway.
