pwjones@... wrote:

> Hmmm .. two key points:
>
> "Noise control equipment can be considered defective where it ... has, in
> the ***opinion** * of an authorised officer, been modified in any way that
> makes it less effective than it would have been if not for the
> modification" .
>
> ie. some (OK, most) aftermarket cans are desired because they make more
> noise
> therefore all aftermarket cans are automatically defective?

Worse than that. All slip-ons are considered defective, as are any cans
with removable baffles even if you leave the baffles in place AND throw
in a screw or two to make sure they don't fall out.

---
Clause 18 [...] if its noise control equipment is defective or not
securely in place.
[...]
Instead of further defining the term 'securely in place', the department
proposes to make it an offence to use temporary noise reduction devices
on motor vehicles. The term 'temporary' will be defined as including
(but not limited to) components of the muffler assembly, resonator
assembly or exhaust pipe, such as baffles, adjustable baffles, plates
and other silencing devices, that are not substantially welded or
riveted in place.
---

It's a ridiculous legislation - I myself would agree that I "thought it
was appropriate or highly appropriate to regulate motorcycles and
modified motor cars by specifying a maximum noise level." That doesn't
mean I would automatically agree with whatever arbitrary maximum noise
level that the DECC specifies. I'm curious as to what they've set that
limit at - apparently it's in Schedule 1 which I haven't seen yet.

Regardless, and here's the ridiculous bit, Schedule 1 won't be used.
Ever. Because they can't possibly set the noise limit to less than the
ADR level, and vehicles designed to ADR's, ie. all of them, MUST be at
or below that level. But if an aftermarket can is louder than the
factory can BUT STILL QUIETER than the ADR level or the DECC's noise
level ... it's still defective!
WTF?

*search, search, search...*

OK. ADR's specify a maximum noise level of 80dB(A) for motorcycles >175cc.

The Noise Control Regulation 2000 Schedule 1 specifies a maximum noise
level of 94dB(A) for a "motor cycle designed or manufactured for use on
a road" or 100dB(A) for "Any other motor cycle".
(note: 100dB is a -shitload- louder than 80dB, see footnote)

So you buy a bike. It's designed to ADR's so makes less than 80dB of
noise. In fact, they came in well under the mark at 70dB.

You put an aftermarket can on it. Now your bike makes 74dB of noise.
It's still within ADR compliance and WELL within NCR200sched1
compliance. In fact, the manufacturer might ship next year's model with
the same 74dB can you just put on..
.. but your bike is defective because its 74dB is louder than the
factory 70dB.

That's some crazy shit.


-Pik.

*footnote
According to Paul Tipler's Physics For Scientists and Engineers (Third
Edition, 1991 by Worth Publishers):

Normal Breathing 10dB
Soft whisper (at 5m) 30dB
Normal Conversation 60dB
Busy Traffic 70dB
Average Factory 80dB
Niagra Falls 90dB

Another frequently used reference is 100dB for a 747 jumbo jet taking
off from a couple of hundred metres away.

+10dB is "about twice as loud"