Silencer for Series C Comet

Matty

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When I first had my Comet in 1956 it had a Burgess Silencer which by 1967 had fallen to pieces.

I bought a pattern one in Mansfield which had very poor Chrome and had it re-plated.

This was fine until about 10 years ago when I blew out the rusty baffles onto the TT Course in the Isle of Man.

It was then VERY noisy but the chrome still looked great.

I bought a second hand much quieter one from Tony East in the IOM to get home, but brought the old one back as a spare.

The Comet has seemed for many years to have been rather gutless and very reluctant to rev much above 60 in 3rd, but I did not notice a significant reduction in performance after fitting the quieter silencer in the Isle of Man - thought the problem was probably worn cams which was a puzzle because the lift etc. looked OK.

About a year ago the Tony East one was looking tatty, so I bought a new silencer for a very good price from Armours. This was of very good quality, but very noisy, so I put my old chromed, but empty one on to try and found that the bike went much better and was not much more noisy than with the Armours one. The Comet however was transformed and would easily go to 70 in 3rd with my noisy old silencer. To be fair the performance with the Armours one may have been better than the Tony East one, but I only tried it for a very short time and even with ear plugs it was painful for me to ride with it due to the noise. I had a word with Armours who said that this was their normal Vincent straight through silencer.

So I sold the Armours one to a friend and it seems OK on his Rapide, but what is the best silencer solution for my Comet, which will give good performance, be fairly quiet, be good quality, and not cost a fortune, please.

Matty
 

davidd

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Matty,

If you do not mind the looks, I know that the Super Trap has worked well for some Vincent owners. Its great selling point is that it is adjustable, which means that you can make the adjustment between noise and performance. It does not look stock, but if you keep an old stock looking muffler on the shelf you may not feel so bad. It would be nice to get a response from Knobby, who makes a lot of power but rides on the street.

David
 

Black Flash

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I just missed the TÜV (mot) with my Black Flash last friday because of the noise. I have a Goldstar type silencer from Armours fitted to my 600 cc Terry Prince topend kit Comet. she has twinspark ignition and approx. 10:1 cr with the squish band head.
the noise was deafening, almost like a Norton Manx with a mega in the paddock. My brothers bike also needed TÜV, so we fitted the old Campbell silencer where the baffles had also disintegrated and his Comet was not much quieter as well. the idea was to say he already had TÜV with this exhaust before and so there would not be too much noise difference between the two bikes.
When we fired the bikes up the other TÜV guys came running out of their shed and well be both failed.he then fitted back the new ( we have two types of these, this one is the one with a bigger maybe 1/2" hole down the middle) spiral baffle silencer which muted the bike a lot and lost the grunt of his bike.

I spoke to Armours and they told me that all their silencers are made without any wadding! this really surprised me as I cannot think of any working absorption type silencer without wadding if for more than 250 cc. Nevertheless the were very helpful and explained to me that the cannot fit wadding to chromes silencers due to their processing, but they can certainly do with s/s ones.
If I was you, try getting one of the TOGA straight through absorption type ones, maybe second hand. they are noisier than the spiral ones, yet still not antisocial and without the baffles disturbing the flow your engine can breathe properly and will lose very little at all.
you can also ask Armours to built you the same type from stainless, but then you have to live with the yellowish straw colour the silencer will have after its first blast.
cheers
Bernd
 

nobby

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Since my racing days I use a stainless Supertrapp with a 2" pipe on the Comet, on the 500 but also on the 600. It is adjustable, you can alter the amount of silence plates, you can also use an open cone at the end. But this will produce a lot of sound...
WIth a not silenced Supertrapp, and open cone I once produced 120dB in low revs. For reasons I still do not understand, when going fast on the track there is less sound!
There are also lightweight alu versions, those are also shorter. I do not like the looks of those. With the 600 I went with the help of Peter Volkers to the dyno, we fiddled some with jetting and silence plates, and at the end we got 39.8 bhp out of it. The discussion is to be found here : http://www.vincentownersclub.co.uk/showthread.php?2842-Comet-to-the-dyno-test&highlight=dyno
The dynoclip was posted to youtube, but I could not find it, maybe I have to upload it again?
1999.JPG
 

nkt267

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I am now using a stainless silencer from Armours on my Comet and it is quieter than the chrome Toga that I used to have on it.
With the Toga 'silencer' the Comet could be heard from over a 1/2 mile away. Nobody would ride behind me though..John
 

Black Flash

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Hello Cornelius,
I really like the idea of fitting a Supertrapp to the Black Flash, but it will not be accepted by the German MOT as it is not original. So fitting this kind of silencer will make it impossible to use the bike with an 07 number(up to ten historic vehicles, no more MOT, only the most expensive needs to be taxed and insured) and they want you to mute the silencer until your p&j sounds like a 2011 Yahosukaki.
 

Matty

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Thanks all

Seems I'm not the only one trying to find the best compromise between noise, performance, cost and appearance for a silencer for my Comet.

It would have been interesting to know how noisy and what performance was available with the original Burgess silencer, which I believe was straight through but with wadding to reduce the noise - certainly you could see straight through it. The Burgess was on my Comet for about 10 years and as far as I can remember was not very noisy and gave good performance. During this time (1960) for instance I went two up via France and Germany to Austria/Italy including over the Grossglockner Pass and seem to remember cruising at 75mph or so on the Autobahns. It would seem a pity, if this is true, that nobody has produced a copy of the original Burgess.

Or is it a case of the older I get the better it was ?

My Comet is very original so I am reluctant to use a silencer which does not look like a Burgess, but it looks as if I may have to use the straw coloured Armours one in the end if nothing else is available.

The noise does not seem to be a problem with my MOTs so far - only for my ears, and is OK with good earplugs. My test station have never wanted to hear the bike running and fortunately only seem interested in safety issues - brakes, wheel bearings, lights, head bearings, spokes, forks etc.

Thanks again for the information so far - perhaps I should commission the design and manufacture of a Burgess copy !!

Matty
 

Black Flash

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From what I can see the Burgess was a pretty crude design and a lot depended on a tiny baffle plate size of 2 Euro coin drilled with holes fitted into the middle of the straight through section about 5 inches from the entry.
if this "coin" goes awol you are getting a pretty straight through design with matching noise. If you have no noise problems, get a Toga one.
Just by listening to the noise of your Comet you start dreaming about Manxes, etc.
 

vibrac

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Two items on Comet silencers
First My Comet Racer has to comply with 105Db (yes I have a meter) it regularly comes out at 102-104 depending on grass or hard standing for the test. it exits at waist height (closer the ground louder it is) its a 2" straight through absorbsion silencer (including pipe) custom made by NRP exhausts (picture here http://www.oldracer.co.uk/gallery.html ).

Second I belive that those lucky people with the few road going Flashes found that a Brooklands Silencer gave better performance than the standard spiral job I wonder if they were fitted at the factory? certainly am contemplating it on my Flash and will publish the noise results in the Grey Flash Diary
 

Hugo Myatt

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Comet Exhaust

I have always loved this quote from the Comet road test report in 'MotorCycling', Jan. 26th 1950 -

"At larger throttle openings the exhaust note possessed a crisp, taut note that, in town, may have attracted some attention, but seemed to add to the enjoyment of the ride in the open country. It did not become wearing after a long journey and could, by considerate use of the throttle, be kept satisfactorily within bounds in built-up areas."

Classic weasel.
 
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