Noise Testing ...
Why do we need noise testing ?
Noise is one of the main complaints against motorcycles especially the off road variety.
Noise is cited as the main reason for losing riding areas. In order to protect our access to the areas the T & E MCC uses for hosting our events we must take a proactive stance in managing this issue.
The T & E Club has purchased a Noise Testing Kit and some club members are now qualified M.W.A. Noise Control Officers trained to noise test motorcycles.
Who will be tested ...
The Clerk of Course will select which bikes are to be tested.
Also any bikes which failed the Noise Test at the last event where they were offically tested.
The Noise Testing procedure...
The selected bike is moved to the centre of the Testing Area - see diagram - with the front of the machine
The Testing Area is basically a 10 metre diameter circle clear of all obstacles with background noise no
greater than 80 dB(A).
There are only 3 people within the 6 meter diameter circle, the Noice Control Officer( NCO ) , their assistant
and the rider.
The rider is in control of the bike at all times and is responsible for starting and bringing the engine up to
the required revolutions for testing as directed by the NCO.
The NCO's assistant is responsible for determing the correct RPM's by holding the "Treysit" Sirometer
( resonating wire ) Tachometer against the bikes crankcase and indicating to the NCO when the bike is at
the correct RPMs.
When the engine is at the required RPMs as indicated by the Tachometer the NCO will take a noise reading
from the SLM.
This noise reading along with the Date, Time and Temperature and other details are recorded in the
Recorded Noise Test Log. This log is available to MWA and will be retained in the Club records.
The Noise Limits ...
The following table shows the RPMs for various engine types.
The Noise Limit for Enduros is 94 dB(A) as per General Competition Rules ( GCRs ) 12.10 Noise Emmissions.
The Noise Meter reads in 0.1increments.
All readings are rounded down - for example : a reading of 95.6 dB(A) is rounded down to 95.0 dB(A)
A further correction is made to the reading by deducting a further 2 dB(A) from the reading. This is because the Type 2 Sound Level Meter (SLM) used are accurate to within +/- 2 dB(A) and this deduction ensures no one is disvantaged by a SLM reading high or low. The SLM is calibrated at the start of the testing session using a
Sound Level Calibrator.
The highest legal limit is - 96.9 dB(A) which when rounded down and the correction applied equals 94 dB(A).
I have been Noise Tested now what ?
Depending on the reading one of two things will happen ....
If your bike is under the limit then off you go and have a good ride ...
If your bike is over the limit then the NCO will fill out a Noise Test Failure Report.
There are 3 copies of this report:
The rider will recieve a copy, the Clerk of Course will recieve another and the third is a file copy for the Club records.
It is up to the Clerk of Course what action will be taken - not the Noise Control Officer.
The penalities can be but are not limited to:
Basically a 3 Strikes and you are out policy ... until you get it quiet enough.
Additional Information ...
Operation Manual - for use by Noise Control Officer - courtesy of Derek Rumble
Current General Competition Rules - courtesy of Motorcycling Australia
Up to 85 cc
85 cc to 125 cc
Over 125 cc up to 150 cc Four Stroke
126 cc to 250 cc
251 cc to 500 cc
Over 500 cc
First Official Test and any subsequent tests
Pass ( reading <= 96.9 dB(A) )
None - go and ride !
First Official Test
Fail ( reading > 96.9 dB(A) )
Warning and bike must be compliant at the next event where it will be tested again prior to the start of that event.
At next event after First Offical Test and Failed
Fail again ( reading > 96.9 dB(A) )
Penalty of 30 minutes - bike MUST be compliant at next event.
Tested at next event and previously Failed at least twice
Fail again ( reading > 96.9 dB(A) )
Can NOT Compete - the bike will be tested at every subsequent event until compliant.