Mk.lll 850 exhaust down pipes

After trying a pair from Armours, which were no where near, fitted a pair from Mick and Angela Hemmings to my Mk3. Went straight on and still look good 7 years/43,500 miles later,

Simon.

The pipes are the 'square' flange type, so I use a couple of crush washers per pipe, with the standard Mk3 retaining collars lock wired.

My strong recommendation is not to fit unbalanced pipes, you will ruin the bike. Balanced pipes were designed to reduce the noise, which they do admirably. It means that you can run on straight-through peashooters and gain a lovely open rumble, without the loud 'crack' that you hear on unbalanced pipes.

Also, I believe that the torque at lower revs is better on balanced pipes. I recall following other Commandos (mine balanced and others unbalanced) and they would change down to come out of roundabouts in second while mine was on their tails still in the same third gear.

Go for it Sam! Brash, noisy, antisocial is what early Commandos were all about. If you want quiet buy a car! I now rumble along, at around 75 m.p.h., on my old Dominator, but often miss the racket when I wound my 750 Commando over 90 in 3rd gear!

BLR Engineering Ltd of Wallington do a whole range of downpipes for most Britclassic bikes. Bought both unbalanced and balanced pipes for my Mk 3 Commando off their stand at Kempton a couple of years back - they've always been their every time I've attended subsequently.So far no problem and quality seems OK.

Previously norman_lorton wrote:

My strong recommendation is not to fit unbalanced pipes, you will ruin the bike. Balanced pipes were designed to reduce the noise, which they do admirably. It means that you can run on straight-through peashooters and gain a lovely open rumble, without the loud 'crack' that you hear on unbalanced pipes.

Also, I believe that the torque at lower revs is better on balanced pipes. I recall following other Commandos (mine balanced and others unbalanced) and they would change down to come out of roundabouts in second while mine was on their tails still in the same third gear.

Sorry Norman, Can't agree with you there, I replaced the ballanced pipes on my Roadster years ago with unballanced 750 type but kept the peashooters that it already had. Honestly didn't notice any difference in noise, except it much reduced the poping & banging on the over run, I guess the ballance pipe didn't seal 100% although it always seemed well sealed, & as for low down torque, I always thought it was much improved, the bike will now happily hold 30mph in top, two up, & accelerate rapidly when required without changing down, it's one of my favorite features of the bike. All that said, I do, & did before the pipe change, run SU carb.

Regards, Tim

My MkIII wears non-balanced pipes with peashooters.

Interestingly they also sport spherical flanges, which of course pretty much banish alignment problems .

I'm afraid I can't tell you where they came from or when, - I think the previous owner put them on and he used Mick Hemmings more or less exclusively. Anyway it's probably worth a call to Mick to see if he knows anything about them

Regards, Rob.

My Mk 3 uses unbalanced pipes with pea shooters too. The only problem is that the LH down pipe can touch the bottom of the primary chain case. An extra spacer on the LH pea shooter and taking a bit off one of the bottom Alen heads just about does it. Yes it is loud but very nice. Stainless 750 type air filter used with a single Mk 1 Amal 32 mm carb. From 45 mpg as standard,now to 68 mpg..

Bought the down pipes from Carl Rosner about 20 years ago and still on. Watch out that the flange into the head is made of solid stuff, they have been known to break off. These I fitted wereas per Dommie, with the standard exhaust washer. No air leakes either.....

Hi Sam,

I have had both types on my Commandoes and must agree that unballanced is the way to go ! However I recently replaced the separate pipes with balanced because they were scraped and,allegedly no one is making exhaust pipes for Andover Norton at the moment, and those that are appearing on the market are crap ! The alternative would be NOS if you can find any !

Cheers

Hans

Yes Interestingly I'm also on a single 932 concentric mk1. I get 45 around town up to 60 mpg on a run.

Previously sam_milner wrote:

Previously hans_taylor wrote:

Hi Sam,

I have had both types on my Commandoes and must agree that unballanced is the way to go ! However I recently replaced the separate pipes with balanced because they were scraped and,allegedly no one is making exhaust pipes for Andover Norton at the moment, and those that are appearing on the market are crap ! The alternative would be NOS if you can find any !

Cheers

Hans

Hi Hans,

I've fitted an old set of unballanced pipes for the moment till I get some new ones. We just got back from Spain on the Commando, looking at the rain I wish I was still there !

Went on the later rally, back at Colombres.

cheers

sam

We always seem to come back to rain !

Ping me at springbok.racing@tesco.net, would love to hear what the 'alternative ' was like ??

CheersHans

Still waiting for my MKIII balanced pipes to break!! though I have been tempted to renew the exhausts to unbalanced. If anyone does find a manufacturer then that would be ideal as I would want them un-chromed and and then get ceramic coated to suit the new black chrome silencers from ANL.