New forum member wants to say HI

[Peter R]

Hello all, I am new to this forum ,and want to introduce myself, I am a 850 Commando owner since 1975, still in original paint (although the red paint is severely faded now)
My Commando is sharing the garage with a Triumph Trident, and an ongoing BSA Goldstar project.
Since my retirement I have found more time to ride and work on my bikes, although winter has set in early in this country (Netherlands), and roads
are a bit icy at the moment. Here a picture of my Norton, it has several mods, some more obvious tan others.

Regards, Peter.

 

[ashman]

Hi Peter

For the age of your bike the faded paint looks great and welcome, as well I have owned my 74 Norton since new, as well I also love the Triumph as I have owned a few over the years but the Norton has a lot more grunt, but mine has a nice big cam and has a lot of work done inside, as well I don't get snow here so I get to ride all year round, but your bike looks great...

Ashley

 

[grandpaul]

Wecome, Peter.

I quickly spotted the full floating front rotor, finned rocker covers and what appear to be Amal mark II carbs.

Nice bike!

 

[Gino Rondelli]

Welcome Peter
Plenty of Norton Enthusiasts in your part of Europe, great Classic Bike scene in the Benelux countries, hope you take part!
Nice bikes!

 

[aceaceca]

Meticulous looking machines. I love the Trident with the buck rogers exhausts. Well done.

 

[lcrken]

Nice bikes, Peter. And a tidy looking work area too. Welcome to the forum.

Ken

 

[marknorton]

Peter, You are very welcome. Are your exhausts original, and do you have a balance pipe on the downpipe exhausts?
My Commmando I am refurbishing had similar exhausts to yours and I am led to believe that these exhausts ( my machine downpipes were also without a balance pipe) are not original.
So I am very interested to see your Commando with what looks like a similar setup.

 

[L.A.B.]

Are your exhausts original, and do you have a balance pipe on the downpipe exhausts?
My Commmando I am refurbishing had similar exhausts to yours and I am led to believe that these exhausts ( my machine downpipes were also without a balance pipe) are not original.
So I am very interested to see your Commando with what looks like a similar setup.

I think the only 850 models likely to have their original balanced exhaust pipes and black cap silencers will be the ones which occasionally still turn up in their crates!

The 850 balanced exhaust pipes regularly fractured around the cross pipe stubs, and the restrictive annular black cap silencers were moisture traps, so they rotted out quite quickly and that's why most 850 owners usually fit the peashooters and unbalanced pipes option (and it sounds better ).
Peter R's exhaust appears to have a mis-match of exhaust brackets in the photo (with two black cap brackets and either one peashooter bracket or a custom made bracket?) so the exhaust system is hanging rather lower than it should be, which may be stressing the pipe-to-head joints?

However, a large number of 850 Mk2 models were also produced alongside the Mk2A version during 1974.
The Mk2 had peashooters, slightly different carbs and the older style metal perforated airbox unlike the Mk2A's which had black caps and plastic airbox-but both types had the balance pipe system.
The majority of 850 Mk2's were sent to the USA.

 

[Spaulding]

My '74 850 has the balanced pipes and the assembly still appears to be solid if not very pretty. Must be the low mileage at work. So if I need to replace that part of the exhaust at some point is the replacement always "unbalanced"? I have an airhead beemer that has the same kind of balanced pipe setup too... What is the theory behind the balancer?

 

[Hobot]

Cross overs are ancient way to get less resistance of exhaust exiting at slower exhaust velocity- rpm by giving more ports to flow out of. All Cross overs tend to lower soften the pops and was main reason in 850's for US sound laws.
Its not same as a 2-1-2 or 2 into 1, as does not provide much use of pulses to pull the others out as a race set up might. Basically a way to soften noise, add some grunt down low and not subtract from top end power, just not adding to it.

Old hot rod method to find best spot to connect pipes was marking length with a crayon then run up to desired rpm the shut off and cut holes where the crayon melted the most. Space limits ideal but almost any where fairly close to head works. I always cross over my old V8 stuff for the soften stronger real work use.

BTW its not just cross overs that fracture their headers in Nortons : (

 

[Peter R]

Marknorton, This bike is a Mk2A, and came originally with Black cap silencers and a balance pipe.
They have long since been replaced by the peashooter silencers and no balance pipe is installed now.
As stated in the above postings, the balance pipes cracked at an early stage, and the black cap silencers did not last long either.
With the original setup the noise level was considerably lower, but the power output went up with the peashooters installed.

regards, Peter

 

[L.A.B.]

So if I need to replace that part of the exhaust at some point is the replacement always "unbalanced"?

You don't have to use the unbalanced pipes if you don't want to, although black caps are supposed to work better with the balanced system-apparently.

I have an airhead beemer that has the same kind of balanced pipe setup too... What is the theory behind the balancer?

As hobot said, the primary function of the balance pipe was to reduce noise. It has been said that a balanced system can increase power, but as ludwig discovered with his balance pipe test apparatus (a remotely operated butterfly valve fitted inside the balance pipe which could be set to open or close the tube) if there was any actual power gain from the balance pipe then he wasn't able to notice any difference.

 

[nortriubuell]

PeterR, I joined this forum myself just recently, and it's a great place for Norton enthusiasts to exchange information. I find myself on the site a couple times a day anymore. Does that make me a "Norton junkie" ??? Maybe so. Anyway,
"Welcome aboard" !!!