poor quality repop silencers

Jez Nemeth

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Non-VOC Member
In the photo of the internals, perforated tube that I assume runs the length of the silencer section, but with an easily opened perforated end, easily drilled with extensions I'd think, alternatively and a bit Neanderthal, but could well rip the perforated tube from the three lines of spot welds and out the back end I wouldn't mind betting, if you wanted an open system, hitting it from direction of flow of course..has its risks but possible.
 

Bill Thomas

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I would not knock it about, I told you of the one I saw at Armours, That had been sent back as Faulty !.
The welding is done much better than years ago. Bill.
 

Jez Nemeth

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Non-VOC Member
Ahh yes -saw it on reading back, what I meant to say was precision drilling. Glad to hear the insides are good quality. :)

Thinking around this -if the finish quality of the repo is poor, but mechanically it's well put together -does it make any sense to get it re-chromed to a satisfactory standard, and who would be good for that?
 
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Black Flash

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VOC Member
I have an old and rusty burgess absorption type silencer lying around in my garage.
This silencer also has a perforated disc fitted about midway in the silencer.
The straight through one I bought from Armours [perfect chrome and polish btw] about a year ago does not have this disc inside.
I also got one for my friend Dieter and everyone says it is very noisy. On his way back from a brit bike meeting near Switzerland he got stopped by the police in the tourist area of the black forest because of the noise.
When he showed them the documents with the old noise emission typed in there, the police gave up on him and he happily rode away.
 

Martyn Goodwin

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Non-VOC Member
I have an old and rusty burgess absorption type silencer lying around in my garage.
This silencer also has a perforated disc fitted about midway in the silencer.
The straight through one I bought from Armours [perfect chrome and polish btw] about a year ago does not have this disc inside.
I also got one for my friend Dieter and everyone says it is very noisy. On his way back from a brit bike meeting near Switzerland he got stopped by the police in the tourist area of the black forest because of the noise.
When he showed them the documents with the old noise emission typed in there, the police gave up on him and he happily rode away.
Exactly what documents are you referring to??
 

Black Flash

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VOC Member
@Martin
In any document we have to carry around for every road registered vehicle it states the noise of the vehicle running stationary and a noise which is now measured at 0.5 m distance from the outlet at 45 degrees at 75% of maximum RPM.
The documents show the noise in dbA.
Now a bike from 50s and early sixties was measured at a drive by 20 m distance second gear at 50 kmh and accelerating for 20 meters and suddenly shutting off.
This noise is referred in the documents with the letter N.
Officially when you measure near field you have to add 21 dB to this number plus a 20 % tolerance.
My comet has 85 N in the documents, the shadow 87,which means as long as I stay below 110 and 112 dbA accordingly with a near field measurement I am safe.
 

Martyn Goodwin

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Non-VOC Member
@Martin
In any document we have to carry around for every road registered vehicle it states the noise of the vehicle running stationary and a noise which is now measured at 0.5 m distance from the outlet at 45 degrees at 75% of maximum RPM.
The documents show the noise in dbA.
Now a bike from 50s and early sixties was measured at a drive by 20 m distance second gear at 50 kmh and accelerating for 20 meters and suddenly shutting off.
This noise is referred in the documents with the letter N.
Officially when you measure near field you have to add 21 dB to this number plus a 20 % tolerance.
My comet has 85 N in the documents, the shadow 87,which means as long as I stay below 110 and 112 dbA accordingly with a near field measurement I am safe.
Ahh - so its a EU thing. See my earlier post #92. Life is so much easier here in the penal colonies!
 

vibrac

Well Known and Active Forum User
VOC Member
@Martin
In any document we have to carry around for every road registered vehicle it states the noise of the vehicle running stationary and a noise which is now measured at 0.5 m distance from the outlet at 45 degrees at 75% of maximum RPM.
The documents show the noise in dbA.
Now a bike from 50s and early sixties was measured at a drive by 20 m distance second gear at 50 kmh and accelerating for 20 meters and suddenly shutting off.
This noise is referred in the documents with the letter N.
Officially when you measure near field you have to add 21 dB to this number plus a 20 % tolerance.
My comet has 85 N in the documents, the shadow 87,which means as long as I stay below 110 and 112 dbA accordingly with a near field measurement I am safe.
Thats quite a noise! I am surprised seeing race circuits in UK are at about 105Db.
I see that the Bedford (UK) Mayor (he who called pot holes 'natures little sleeping policemen') is introducing noise cameras, he had better sort the legislation out first with regard to historic vehicles or a lot of time will be wasted. I just got my Trigrumph on the road it has an off road trials type silencer far too noisy I made up a short end can to fit over the end 15 X 1/4" holes equaled the outlet size of pipe, result? a great burble.
The Egli Comet also hit the road this week (A great week for finished projects) that has a pattern Goldie silencer far to noisy but at least you can keep the revs down locally
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