Silencer shapes

Is there any perceivable performance difference between the roadster and interstate silencers.
Other than a 2-1 I ran years ago I've only had the interstate silencers fitted and when I look down them they are parallel bore along their length, so is the cone/reverse cone difference just for aesthetics, it doesn't appear to serve any function, or are they different lengths when fitted to their correct headers?

Paul.

So tell us how they perform ?

You'd think that Nortons would have documented this sort of stuff, but I've never seen anything written down about this.
You often see Interstates converted over to peashooters too, but never a word about any performance difference.
There is nothing in the manual about jetting changes either.
So maybe there is no difference. ?

Well they perform admirably, but in my memory not quite as much low end grunt as the 2-1 that had a short cone mega on the end, but the bike also had an su carb on it back then and was off the road for a few years before fitting the interstate silencers so not really a back to back comparison, I've never ridden a commando with the roadster type pipes but I've heard plenty of them and they sound pretty similar ie. awesome!! like most commandos. As time goes by I realize the interstate silencers are out of favour by many so this might be a difficult question to answer, but my interest lies in the fact that I keep hearing that interstate cans are going to be discontinued so I foresee myself with roadster cans fitted sooner or later.
Another point is its a pain in the arse getting my rear spindle out, the exhaust needs removing first due to the low level.

When I fitted peashooter/roadster silencers to my Interstate, I really did not notice any difference from the Interstate silencers I had originally, now I am not sure if the originals were original Norton, or aftermarket, so maybe not a fair comparison?, the replacement roadster silencers were genuine Norton items, at the time the Interstate type did not seem to be available.

I can't recall as to whether the roadster silencers were longer or shorter than the Interstate ones, but I do seem to remember I had to make mounting plates, as the mounting lugs on the roadster silencers were in a different position once fitted to the exhaust pipes.

John

At one stage I ran a Roadster & a Interstate ' muffler ' one Ea. side . both with the glass pack left on the slipstream years previously .

I think with 220 main jets at 110 continuous it was W H I T E inside the entire exhaust system , and cracked up the Interstate muffler around the mounting lugs ,
The Rear Cone on the I S appears to be the Front Cone from the Roadster , front inter Cone a sharper taper , so a more traditional mega .
Luckily , with the rear or the interste muffler bungyed to the luggage , the traffic Cop in the middle of the road at Narawhariga was preoccupied with the Semi
broken down in the North Bound Lane . Trickling there was no noise anyway , untill 20 mph .

Id think with the Glass pack gone , the Cone of the front mega. on the Inter Muffler ( Interstate not international ) would be effective for its purpose .
Increaseing output at redline . :twisted:

Mentions Jetting change if Mutes Fitted .

The early Glass Pac. ' straight thru's ' ( looking up or sticking broom handle - ' traight Though ' ) the ' baffle ' :lol: should be highly perforated , akin
to This .

Thus Jetted over on the Mains , the throttle assunder , the Baffle becomes incandescent .
This ignites the Excess Mixture . Thus the Scavenge Effect is Enhanced considerably , allowing the tuned induction to obtain full effect . Thus the Accostics are Phenominal .

In this case , I think the Interstate Silencers have certain advantages . And consider the design quieter than the full length expanding taper silencers .





Id consider these on roadster headers , if straight thru Glass Pac as a good retro set up , if the neghborhood is of superior sensabilities .



The olde plunger A7 / A10 type , if panniers on interstate pipes could be acceptable . though Dia. is over so reducer / sleeve Reqd.

The WASSELL 16 G. taper Cone - perforated baffle have superior acustics tone and resonance - for maximum evacuation . the P. R. headers superior ground clearance - so avoid marring the chrome finish in enthusiastic opperation . :mrgreen: