[ST] 3K Engine Vibration - One more Time

["Rick Hartwick" <hartwick@xxxxxxx>]

Not to belabor the point much more, but the 3,000 rpm vibration is
deliberately designed into the engine.  Rider magazine tech section
discussed this a few years ago.  A counterbalancer and engine will always
wind up producing vibrations somewhere, due to the harmonics.  Triumph
designed the counterbalancer to place the vibrations right about 2,800-3,000
rpm, where they would be unintrusive, and out of the main powerband.  I
notice this vibration band is much less on the 955 motor than the 885 engine
in my old Trophy.  I always think of this as an endearing, cute quality of
the 3 cyl motor.  As for the racket at idle, it can be scary - it does sound
just like a tractor, except the old Allis we used to plow with when I was a
kid was much quieter. I keep telling myself not to spoil my enjoyment by
worrying about the many noises coming out of the crankcase (or how I learned
to quit worrying and love the bomb). Just use earplugs, and ignore the
noises, and keep telling yourself the bike is under warranty, the bike is
under warranty, ... so why worry?  (except for piston slap that is, as we
all recently saw).   Of course, at 5-6K rpm, where this motor lives, then
the engine noises become a syphony!

Rick Hartwick
00 ST


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