Anti-Vibration Handlebars
HAV Testing

To demonstrate/refute the value of the Hav-Not we devised a test that would measure the actual motion at the bar. We did this by connecting an inductor to the end of the bar then striking the bar with a pendulum mounted mallet. The output from the inductor was input to an oscilloscope for interpretation.

Far End Test

Without Hav-Not

Data Block					Cursor Values 
Name     =  Input A				X1:     9.6 ms
Date     =  1/21/1995				X2:   109.6 ms
Time 	   =  8:29:16 PM			dX:   100.0 ms
Y Scale  =  500 mV/Div				Y1:     0.80   1.24 V
Y at 50% =    0.00 V				Y2:     0.00   0.06 V
X Scale  =   20 ms/Div				dY:    -0.80  -1.18 V
X At 0%  =  -40.0 ms
X Size   =  250 (250)
Maximum  =    1.24 V
Minimum  =   -2.02 V
	           

With Hav-Not

Data Block					Cursor Values 
Name     =  Input A				X1:    10.4 ms
Date     =  2/4/1995				X2:   110.4 ms
Time 	   =  7:00:30 AM			dX:   100.0 ms
Y Scale  =  500 mV/Div				Y1:     0.32   0.74 V
Y at 50% =    0.06 V				Y2:    -0.02   0.02 V
X Scale  =   20 ms/Div				dY:    -0.34  -0.72 V
X At 0%  =  -39.2 ms
X Size   =  250 (250)
Maximum  =    1.06 V
Minimum  =   -1.00 V
	           

This first test (shown above), called, "Far End", shows how energy is transmitted from one end of the bar to the other. The bars were struck at their end, with a pendulum mounted mallet; the effect of the mallet strike was measured at the opposite end of the bar. Motion is noticeably reduced, by nearly 40%, in frequency (how quickly the bars vibrate), amplitude (how much or how far they vibrate) and duration (how long they vibrate).

Middle Test

Before Hav-Not

Data Block					Cursor Values 
Name     =   Input A				X1:   4.8 ms
Date     =   1/21/1995				X2:  54.8 ms
Time 	   =   8:37:57 AM			dX:  50.0 ms
Y Scale  =   200 mV/Div				Y1:  -128   376 mV
Y at 50% =  -176 mV				Y2:   -16    16 mV
X Scale  =    10 ms/Div				dY:   112  -360 mV
X At 0%  =   -20.0 ms
X Size   =   250 (250)
Maximum  =   488  mV
Minimum  =  -904  mV

After Hav-Not

Data Block					Cursor Values 
Name     =  Input A				X1:    5.2 ms
Date     =  2/4/1995				X2:   55.2 ms
Time 	   =  7:02:05 AM			dX:   50.0 ms
Y Scale  =  200  mV/Div				Y1:  -216   104 mV
Y at 50% =   24   mV				Y2:   -24    -8 mV
X Scale  =   10   ms/Div			dY:   192  -112 mV
X At 0%  =  -19.6 ms
X Size   =  250 (250)
Maximum  =  408   mV
Minimum  = -712   mV

This second test called, "Middle" shows how energy is transmitted from the handle bar mount, out to the ends. The bars were struck at their center and the effect was measured at the ends. Again, motion is reduced in all three critical, measurable areas, frequency, amplitude and duration.  This test demonstrates how vibration originating at the bar perches (mounts), as a result of engine vibration and/or sudden impacts can be transmitted into the hands.  Please note the unfilled bars tendency to start to move again once it has seemingly stopped. This is due to energy moving back and fourth along the bar; from one end to the other. In contrast, the AV bar dissipates energy in a very predictable manner.

Note:

For more information and documentation regarding the testing and test procedures please e-mail me and I’d be happy to respond.

My thanks to:

Eddie Cole
Gerald Langston
Greg Berg
Mike and Jim at D&S Cycle
Karl Frank
Curtis Carter

for their help and enthusiasm.