While towns, cities etc., can write their own noise ordinaces and could make them a drive by -this standard is a fixed position in neutral.
When you do a drive by, there would also be additional noise generated from sources such as the tires, chain etc.
I think that this standard simply provides an apples to apples test with a set of defined critera that allows for comparison if noise is a consideration.

 

Nice test! Good job.

 

Good Job! I wish I wasn't an ocean away.

 

The 80 dB spec stamped on the muffler cover is referencing the EPA mandated 80 dB 50 FT driveby test. It is an entirely different test than yours. You can find the test methodology using google. I suspect your test is close to 'dead on' since the distance and testing method is different.

Your test method makes sense because it roughly replicates how we would be tested by a USFS ranger, or at a sanctioned event. The driveby test is just one that is currently applied to cars that now applies to motorcycles.

I heard (and sometimes saw) too many obnoxiously loud motorcycles on the trails this summer. The sanctioned rides and races in my state that use state or national land must pass a test just like the one the OP setup. The current limit for 1986 and older machines is 94 db at half the rated RPM.

Thanks for the great post and the stock pipe reference numbers.

 

Thanks for the feedback.

I figured that at least using the stationary standard, we could compare different slip-ons and systems, so that anyone that has to have a lower dB could get one.
Again, if anyone wants to swing by the Syracuse area with other brands, we could post the numbers.