ACTUAL DB law on exhausts?

[Daimo]

Seeing as theres so many rule readers here these days :lol: .

what is the exact actual law on noise readings. Going on my rant about no baffle, and reading the ticket about "as per regulations".

What is classed "excessive noise" or "as per regulations"? Is there an actual db rating? If an exhaust is road legally marked, and has no baffle, is it not still legal? Is ther an actual law that states that a removable baffle in a road legal exhaust must be inserted whilst on the public highway?

Is there an actual law that states "an exhaust/vehical cannot exceed x db level"?

Interesting to know for next time, because what one person considers noisey, another may consider moderatly quiet. I need a good debatable come-back for next time and if there is no exact specific noise law, then surely it cannot be illegal?

Discuss.

[Owenski]

good post, dont know the answer but now marked so I can come back when someone points it out.

[phi-dan]

from http://www.dft.gov.uk/pgr/roads/vehicles/vssafety/regulationsforpoweredtwoandt4564

(d) Exhausts - on motorcycles first used on or after 1 January 1985 the silencer which forms part of the exhaust system must be either:
(i) that with which the machine was first fitted; or
(ii) clearly and indelibly marked with :-
-the relevant BS marking BS AU 193/T2, BS AU 193a, 1990/T2, BS AU 193a, 1990/T3; or
-the relevant "e" marking to show compliance with EC Directive 89/235; or the relevant "e" marking to show compliance with Chapter 9 of EC Directive 97/24; or
-the name or trade mark of the manufacturer or marked with that manufacturer's part number - relating to it.
The European Community noise limits applicable to new motorcycles first used from 1 April 1991 are:
Motorcycle Category by cm3
Limits in dB(A)
Up to and including 80
77
Between 80 and 175 (incl.)
79
Above 175
82

Motorcycles approved to EU Directive 97/24/EC, Chapter 9 will be 2dB(A) less than the above figures.
(Note: the precise regulations for motorcycle exhausts are complex and it is recommended that they are studied closely to obtain accurate and complete details of the requirements).
Before buying any replacement parts for systems listed in this section, riders should check for the relevant marks, where applicable. These will include an "e" mark for EC Directives, an "E" mark for ECE Regulations and "BS" for British Standards.
(Note: amateur motorcycle builders may be exempt from some or all of the requirements)

[yorkie_chris]

"-the name or trade mark of the manufacturer"

Mine's got M4 written on it. Can I tell them to bugger off and find a decibel meter and the relevant method of testing? :-P

[Daimo]

Limits in dB(A)
Up to and including 80
77
Between 80 and 175 (incl.)
79
Above 175
82


This is the bit im guesing?

So really, theres no definitive answer as to what it too loud? My standard exhaust is 104.5db, my official aftermarket exhaust is 107.4db, with the baffle removed.

So really, theres no legal number, there-for no problem? Or am I reading it in-correctly?

[Mr Speirs]

You are reading it incorrectly.

Above 175cc the limit is 82db A weighted.

[muffles]

Limits in dB(A)
Up to and including 80
77
Between 80 and 175 (incl.)
79
Above 175
82


This is the bit im guesing?

So really, theres no definitive answer as to what it too loud? My standard exhaust is 104.5db, my official aftermarket exhaust is 107.4db, with the baffle removed.

So really, theres no legal number, there-for no problem? Or am I reading it in-correctly?

As always with the government the regulations are not clear, but just reading from that link I can see a few things that would, at the least, need clarifying:

- "The European Community noise limits applicable to new motorcycles first used from 1 April 1991 are..."- note it says for "new" motorcycles. It's not clear if this is just required when it is sold new. Also note the points (i) and (ii) above appear to be separate to this as the indentation is different.
- Noise measurement isn't defined, at least in the above link. I'm sure my Yoshi full system is below 82dB from 100 metres away. So you'd need to confirm exactly how the testing is performed. However the above point might render this irrelevant.

[Daimo]

You are reading it incorrectly.

Above 175cc the limit is 82db A weighted.

Does any bike above 175cc fall below 82db? Thats very very quiet. As I say, mines no-where near that, even on a standard exhaust.

Even the E marked one, with baffle, would be above 104.5db as well. Morelike 105/106db. This was around 6000rpm though (noise track day tests).

Even on idle though, it wouldn't fall under 82db?

[timwilky]

You guys need to do a little more reading re marking


(6) Chapter 9 is amended as follows:
(a) Section 2.3.2.2 of Annex II is replaced by the following:
"2.3.2.2. All original silencers shall bear at least the following identifications:
- the "e" mark followed by the identification of the country which granted the type-approval,
- the vehicle manufacturer's name or trade mark,
- the make and identifying part number.
This reference must be legible and indelible and also visible, in the position at which it is to be fitted.";
(b) Section 2.3.2.2 of Annex III is replaced by the following:
"2.3.2.2. All original silencers shall bear at least the following identifications:
- the "e" mark followed by the identification of the country which granted the type-approval,
- the vehicle manufacturer's name or trade mark,
- the make and identifying part number.
This reference must be legible and indelible and also visible, in the position at which it is to be fitted.";
(c) Section 2.4.2.2 of Annex IV is replaced by the following:
"2.4.2.2. All original silencers shall bear at least the following identifications:
- the "e" mark followed by the identification of the country which granted the type-approval,
- the vehicle manufacturer's name or trade mark,
- the make and identifying part number.
This reference must be legible and indelible and also visible, in the position at which it is to be fitted.";



Note the keyword original.


The requirement for marking is on the original exhaust. not replacement.

[Daimo]

So for a replacement, e-marked exhaust, there is no official limit?

Not being awkward, just trying to 100% fully understand the laws on the issue :)

[timwilky]

No, nothing to do with noise limit, that was simply to correct the mis understanding posted about marking requirements to make an exhaust "legal".

[muffles]

Does any bike above 175cc fall below 82db? Thats very very quiet. As I say, mines no-where near that, even on a standard exhaust.

Even the E marked one, with baffle, would be above 104.5db as well. Morelike 105/106db. This was around 6000rpm though (noise track day tests).

Even on idle though, it wouldn't fall under 82db?

- Noise measurement isn't defined, at least in the above link. I'm sure my Yoshi full system is below 82dB from 100 metres away. So you'd need to confirm exactly how the testing is performed. However the above point might render this irrelevant.

? Unless I am missing something, where does it say what form the noise testing takes? It even varies between track days...?

[Daimo]

Ahhh.

So really, im guessing any aftermarket exhaust is illegal, e-marked or not, as they will all be over 82db.

[Daimo]

? Unless I am missing something, where does it say what form the noise testing takes? It even varies between track days...?

I know, and theres nothing about the testing of the noise? No standards to go by? Tested at x rpm, or at a distance, so how actually do they know.

To me, its a major loophole, and one I will now argue if ever given a ticket again.

Especially as we were parked up chatting, bikes off, keys out the ignition, off the road highway on a layby.......

[simesb]

I know, and theres nothing about the testing of the noise? No standards to go by? Tested at x rpm, or at a distance, so how actually do they know.

To me, its a major loophole, and one I will now argue if ever given a ticket again.

You haven't read the full spec so I'd be wary about arguing that there is no standard test. On new bikes, do they not do drive-bys at specific RPM and gear, and is that not part of the reason why many bikes have 'interesting' fuelling at certain points of the curve?

The link given is just an informational website with an extract, not the full specs or standards. There must be some qualifications for an E-mark...

[The Guru]

I know that MOT regulations and Road Traffic Law can sometimes contradict each other and I'm not sure what the law states, but when my bike fitted with a Scorpion Street Extreme (baffle fitted) failed its MOT the reason on the failure sheet was

"Exhaust fitted is clearly in excess of that emitted by a similar motor bicycle fitted with a standard silencer in average condition [7.1.2]"

[timwilky]

The eec directive does state how the test should be performed. It is part of the europe wide type approval system.


just because an MOT does not include anything more than a subjective appraisal for noise, doesn't mean that you are not in breach of construction and use requirements.

[Sid Squid]

My standard exhaust is 104.5db, my official aftermarket exhaust is 107.4db, with the baffle removed.
Measured how? That's the important factor.
So really, theres no legal number, there-for no problem? Or am I reading it in-correctly?
You're reading it incorrectly but it's not your fault 'cos there's a big bit missing - the test procedure.
Your standard exhaust will not be anything like 104.5dB measured using the standard procedure, which isn't anything like standing by your bike with the meter while twisting the throttle.

It's rather like the silliness of the coppers who were testing that bike to see if it made 33BHP or whatever, the test method is everything, if the figures aren't gained by the specific method it's a worthless and meaningless number.

[Daimo]

Standard trackday measurements. 6000rpm with a db reader at the back

So what is the official measurement? So far theres lot of info, but nothing to say I can, or cannot, have an e-marked exhaust without the baffle? Morelike police personnal judgement?

[timwilky]

OK start with eec directive 78/1015/eec.
and amendment 87/56/eec

these require both ride by and stationary measurements and dictate the conditions under which the readings are to be taken.

Cannot find them on line so you go search

[simesb]

Standard trackday measurements. 6000rpm with a db reader at the back

That's the ACU measurement I believe (except they never do it 'right'). IIRC, it is actually an engine speed that correlates to a certain piston speed, with the sensor 2m from the outlet. Obviously, the engine speed should be different for different engines, but they never seem that bothered as long as you 'pass'

Regardless, it's not got much to do with the law for public roads.

[Sid Squid]

Results gained by an ACU or ACU alike test are no use, the procedure is entirely different and thus the figures gained will be very different. The ACU tests were introduced as a way of having a usable track test and is not at all representative of your bike's noise under road homologation tests. Add to this that the ACU test has been applied in a manner of different ways at trackdays, this I have witnessed myself.
I know the Met have, (in the past that is - I've not heard of it recently), used a meter at the side of the road, which is just ridiculous and tells you nothing other than The Old Bill Security Co LTD, (very), are chancers of the highest order, but I'm sure they got some paper results from it as not everyone knows better.
I don't know the current noise test details, but here's a very rough outline of one of the older tests the details of which I do know:
Vehicle under test is ridden/driven at 50% of maximum engine speed in second gear along a straight path, at a given point the throttle is opened fully, at that point there will be a noise meter seven metres away on a line perpendicular to the vehicle path at one metre above the ground level, the test will be done on the 'A' weight scale* which is a measurement scale intended to represent the kind of noise the human ear can detect so it adds weight to those frequencies and removes weight from frequencies that are outside that range, thus the 'A' scale does not represent the actual amount of sound pressure or energy being produced.
This was intended to represent a vehicle being acclerated hard at urban speeds, so the most noise it might make in the circumstance it would be most problematic, I suppose it might work with a Fiesta or similar, what's half revs in second - 30-40mph possibly? It was never very fair on bigger bikes which would be entering the test area at 70-80mph! not exactly town speeds.
Anyway anything you do with a noise meter in your hand is nothing like the test which will have been done to see whether your bike is legal or not.
I stress again I am not familiar with the current test procedure, a search using the details TW has provided may or may not help as it's almost certainly written in language that will seem alien to anyone who speaks human.

*A subject full of a complexity all of its own: see here (http://en.wikipedia.org/wiki/A-weighting)

[timwilky]

To follow up on Sid's post. I have conducted noise measurement in accordance with the directives for type approval.

It is very problematic as you need to first calibrate your speedo/tacho etc. As you need to ensure you are at the optimum speed/revs etc. You need to apply full acceleration at a set point etc. We looked to using an infra red beam to trigger a solenoid to pull the throttle (with driver overide) in order to ensure a consistent point relative to the meter etc.

Otherwise the rider is too distracted ensuring he meets the start conditions to establish the start point on the road where the test is to begin.

I seem to recall there was some work done by the road transport labs for the department of transport on ride by noise testing of motorcycles that established an acceptable ride by interpretation of the directive would be in the region of 102db(a). Motorcycle found exceeding this would more than likely fail the defined tests.

[phi-dan]

Quiet morning so far today, so I followed up Tim's post on EEC directives

Directive 78/1015/EEC of 23 November 1978: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31978L1015:EN:HTML

Directive 87/56/EEC of 18 December 1986 (containing amendments to the test procedure): http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31987L0056:EN:HTML

There is also Directive 89/235/EEC of 13 March 1989 amending Directive 78/1015/EEC (although this is flagged NO LONGER IN FORCE): http://eur-lex.europa.eu/smartapi/cgi/sga_doc?smartapi!celexplus!prod!DocNumber&type_doc=Directive&an_doc=1989&nu_doc=235&lg=en

[Viney]

If its too loud, youre too old. Simple enough test :lol:

[phi-dan]

IIRC, when the later regulations and amendments were proposed by Martin Bangemann (sp?) one of the european biking groups pulled up outside the parliament building with three bikes that were under, at and well over the proposed limits. They then asked various passing MEPs to say which was which, and they all got it wrong...

[simesb]

A bit of light reading there :D

If PC Flatfoot has reason to believe that the OP's can is 'too noisy' even though it is E marked, is re-running a type approval style test the only admissible evidence? I'm struggling for a good analogy; tyres are type approved yet you can be prosecuted for the effects of wear and tear upon them (and tread depth it is easily measured although I do appreciate that the measurement of tread depth has far fewer variables than the measurement of noise, but it was the best analogy I could think of)

I.E. does the type approval process not have more to do with the construction than the use?

[Sid Squid]

Ummm... I dunno*.

* I wish this response to be entered for all the preceding questions, in particular the one about whether TOBSCL(v) can successfully prosecute you for using an exhaust that makes more noise, (and indeed how that conclusion is arrived at), than a given amount.

But TOBSCL(v) aren't much fussed about mere details such as the law or other similar inconveniences quite often - motoring law in particular.

[flak monkey]

The VOSA legal limit is described below. If you built a bike and took it for SVA this is how your bike would be tested.

As this is a roadworthyness test I would suggest that this is the UK legal requirement.

I have put cars through the test, and 99dBa is bloody loud!

Static noise test; Check that when the vehicle is held stationary on an open level surface where there is
an unobstructed area of not less than 3 metres wide all around the vehicle; and the engine by which the
vehicle is propelled is run at a constant rotational speed of; 50% of its maximum power if the engine’s
maximum power is generated at more than 5,000rpm, or 75% if its maximum power is generated at less
that 5,000rpm, that the noise measured at 0.5 metres from the exhaust outlet and at 45 degrees to the
axis of the outlet pipe in a horizontal plane does not exceed the 99dB(A).

[Daimo]

Some very interesting reading going on here.

But from what im reading, JUST becuase I have no baffle, does not mean it is illegal, and unless they demand I go to a test centre, or have a testing kit, I cannot be given a ticket as its down to the officers opinion. Esp if my engine was off :lol:

I'd like to note, i've yet to read through the above links, so my comment is based upon not reading those yet.