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.
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