Ha! I should have mentioned before that there were 200's in it when the concentrics went on the bike and it had already the Cambell's silencer. At that point the plugs showed a rich condition. I brought them down to 180, then finally 160 to get the plugs looking right. So i know that jetting wasnt the issue! But absolutely you are right best practice is to change one thing at a time.
poor quality repop silencers
- Thread starter usefulidiot
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In your chart, there is a big difference in inlet pipe diameter (1.5/8 inches for the Armours vs 2 inches for the VOC Spares one).
Another post mentions 1.5/8 inches so is that the normal size?
Is A's too small or VOC too large, and what does one do to make up the difference?
I have a straight through Toga on my bike. When I first started riding it, it was loud. I am pretty sure it was louder than my Goldstar or my Ducati 900ss. Once I had covered about 2000 miles the bike seemed quieter. Now that it has covered about 8000 miles it is a pretty quiet bike really. The carbon that builds up inside seems to cause more sound absorption. I noticed the same thing happened with my 900ss, after about 2000 miles the sound was different, still not quiet, but it was less harsh. I think the Toga is really good. It obviously can't restrict the flow because you can see right through it.
Dear John,
If you look at the table the 2" dimension is the inlet stub length of the Spares Co silencer against 1⅝" for the Armours stainless item.
The inlet stub and and tailpipe inide diameter are both 1⅝" as stated in the last line of the table.
Since the VOC silencer was developed and financed jointly by the great and the good of both the VOC and Vincent Spares to replicate the original spiral baffle silencer I do not expect it has any incorrect dimensions. Any deviations that other silencers have are by definition deviations from the standard
No two Vincents are exactly the same, right? But exactly how different can they be? Is it possible to have three aberrant Vincents but in exactly the same way? I have three C Vincents, two Comets and a Rapide. All have exhaust pipes sourced from the VOCSC. All the pipes fit correctly. Two of the bikes, one Comet and the Rapide, have stainless absorption silencers acquired long ago. The other Comet had an absorption silencer of unknown origin which was horribly tatty and extremely loud. I purchased a spiral baffle silencer from the Spares Co. to replace the tatty one. It was superb with good quality with great chrome. I offered it up to the Comet. It didn’t fit. The welded on mounting bracket was too short by almost ¾”. The exhaust pipe would have had to have passed through the gearbox for it to fit. This Comet is fitted with a Dave Hills centre stand but comparing the stand plate with the original pillion plate showed that the silencer mounting hole was in exactly the same position. Much head scratching followed. I then offered it up to the other Comet. This one has a ‘D’ type centre stand but utilises the original pillion plate. It didn’t fit – and for the same reason. In desperation I tried it on the Rapide. Same result. I returned the silencer to the Spares Co in case it happened to be a rogue one, but no, it was the same as all the others in stock. Ian tried it on several machines and it fitted perfectly. Has anyone else suffered this phenomenon? Currently I have fitted a Feked item, which has iffy chrome, a mounting lug that is too short, with a poorly drilled undersized hole and welded on ¾” too far back requiring extra bodged bracketry to fit. On the plus side it is quieter, crisper and has ‘subjectively’ enhanced performance. However I should like a better quality silencer that fits as it is meant to. Any ideas?
Hugo
Hugo
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I received a silencer from the VOC Spares Co that was .030" over std on the inlet pipe bore instead of .003" max as specified by the drawing. Cheers, Stu.
I have used the Armour chrome silencer on the Rapide for over 25 years, used in rain snow etc and the chrome is still good. The bracket on the Armours silencer is bolted to the body by two studs welded to the silencer. The bracket is slotted to allow for differences in height. I have followed Andrew Walker who was on one of his Comets and it really went well, but slightly noisy, he has a Armours silencer fitted and claims the absorption baffle helps as it free flowing. On a twin they are a lot quiter due to been two into one exhaust. Best bit is they are only £73.
https://www.armoursltd.co.uk/product/silencer-vincent-comet-rapide/
I wouldn't recommend Armours exhausts for easy fit though.
Simon
https://www.armoursltd.co.uk/product/silencer-vincent-comet-rapide/
I wouldn't recommend Armours exhausts for easy fit though.
Simon
There are formula on the internet for calculating exhaust lengths; most folk use maths by A Graham Bell, I grew up with maths by Phil Irving, I thought this must have been from Tuning for Speed but I now cant find it.
I was shown an interesting way to check the tune of a pipe length with a cigarette paper. We were playing with the straight through exhaust on a single on the beach at Kirk Michael (IOM). I seem to remember it was Dave Taylor (stunt rider etc) who showed us how to slide one piece of straight pipe over/along another slightly smaller bore pipe (eg the down pipe) to find the position at which the gas 'wave' (?) exits with least turbulence. This length starts as a function of the distance from end of bellmouth to back of the inlet valve. From memory if this was eg 7", you would start looking for this low turbulence point at eg 49" (7 x 7"), I cant remember why. This point is altered a bit by revs, but if the length is wrong, at your chosen revs the paper is torn to bits, at the point where the length is correct the paper just waves about in the exhaust gas. At this point the motor seemed out smooth out, calming vibration and improving the exhaust note. I dont know if this point also produce the most power but the bike felt good. I recall its a good idea to tune the pipe length to match the revs where the engine is going to spend most of its time. On some singles the downpipe protrudes well into the silencer so its quite easy to fine tune this length. I've never tried but its hard to imagine this cigarette paper working on a twin?
I think the tail wags the dog the variable is in the dog (exhaust pipe) not the tail (silencer) not all pipes come from the hallowed original Vincent jigs still producing pipes .