650ss siamese pipes

Sorry Stefan - they will fit the earlier head as fitted to 99SS and other 88 and 99 Dominators. The downdraught head as fitted to your 650SS has a steeper angle of exhaust pipe exit. Have you tried RGM or Andover Norton Ltd ? I bought mine from Mick Hemmings Norton but I think he only sells gearboxes now. Good Luck, Howard Robinson

hello try unity equip bolton the caferacer place yours anna j

Now do those 88 / 99 siamese pipes affect power delivery / noise etc?

Paul

I fitted siamesed pipes on my 88SS back in 2001. They were from Armours - and for the splayed late shape head. (Looks like they are not in catalogue now though).

According to my notes, I got the impression that mid range acceleration was better (but no rev counter then so probably not more than 4000-ish) but also got the impression that top end was a bit slower. But that was never very scientific! The books say they gave the 88Ss more at the top - but they would say that, wouldn't they?

I was not happy with the smoothness of the internal joint. The side pipe entrance had significant blockage by the hole on the main tube. I did my best to grind it back.

I get the slight impression that the bike vibrated more, though I haven't a clue why.

They make maintenance slightly easier (but not much)..

I bought them because the original pipes were going rusty. No other special reason.

I don't notice any significant difference in noise. That's more to do with the box I suppose. And at any one time it only carries one pulse I suppose.

I have some fitted to my std (ish) 99. Given the choice I would buy some new ones. I find they make working on the clutch side ,and the rear chain much easier. I also think they change the exhaust noise for the better ,reduce weight and heat up the silencer avoiding condensation and rust. A pair of cheroot reversible silencers will last 3 times as long!. The downside is they are a poor fit , need at least one rose to be of the collet type,and tend to rust at the junction. A set made from stainless and utilizing a std rose nut during manufacture and incorporating a slight kick up in the kickstart area would be perfect.

I managed to purchase one of the last sets of Dominator Siamese SS Head exhaust pipes sold by RGM. Previously I had tried Armours, Feked and Unity Equipe with no joy. UE sell a special 2 into 1 kit (UNA75C) for Norton twins but the fitting requires the main stand to be dumped. Not for me.

The RGM kit was fairly easy to fit, using collets between the exhaust flanges and rose nuts. There were two drawbacks. Firstly, the exhaust flanges sat on a version of the Commando Mk3 round-shouldered exhaust washers. These were so thick that they took away the use of several threads for the nuts. Which consequently kept coming loose. If you dumped these in favour of standard Copper/Asbestos washers the down pipes sat too close to the engine and touched the shoulder of the timing cover.

The second issue, which appears to be common with many pattern parts. The exhaust exit angle was wrong (it pointed slightly downwards) and the pipe end was too close to the kickstart which thumped it when used.

Some bending and fiddling got it all working eventually and as Robert says, there are numerous benefits to fitting such a system.

A few more thoughts, Adjusting the rear brake is much easier too,as is access to the prop and centerstands. I am convinced the pick up is improved (but can't prove it) . Another downside is its not so easy to determine by touch which cylinder is not working so well.However as my 99 is now a snarling lively beast thats not a worry. Whether my old rods will survive the surprising eager power is a worry.

Like Robert I have found they tend to rust inside the intersection of the two pipes. This is a well known issue with electroplating inside sharp re-entrant angles so I suppose a small firm can hardly take the blame. And to be fair to Armours, they fitted very well, with just the usual copper crush washers, and they give a slightly raised silencer angle. One of the roses is captive, so I had to decide on the spot which type to have. None of which is any consolation if Armours no longer sell them. It sounds like I'd have to get them re-chromed if I ever want to go concours...

I rather prefer them. They are slightly unusual, and save a bit of weight (and the price of one silencer), and give better access. The downside is that people expect a British Twin to have two pipes, so disinterested family members prefer two (in so far as they have any preference).

Previously David Cooper wrote:

Like Robert I have found they tend to rust inside the intersection of the two pipes. This is a well known issue with electroplating inside sharp re-entrant angles so I suppose a small firm can hardly take the blame. And to be fair to Armours, they fitted very well, with just the usual copper crush washers, and they give a slightly raised silencer angle. One of the roses is captive, so I had to decide on the spot which type to have. None of which is any consolation if Armours no longer sell them. It sounds like I'd have to get them re-chromed if I ever want to go concours...

I rather prefer them. They are slightly unusual, and save a bit of weight (and the price of one silencer), and give better access. The downside is that people expect a British Twin to have two pipes, so disinterested family members prefer two (in so far as they have any preference).

Hello well if you want to re-chromethe old set be awarenot all chromes will do pipe or silencers that'sbeen used in the past as it mucksup theirbaths and these baths are big and long, but Quality Chrome will and they have a national pick up and delivery service so see www.quality chrome.co.uk they re-chromedmy Manxman silencers and these silencers are like hens teeth to get hold of. and they're not made by the aftermarket and too complex for Armours to make they will not touchthem, only for the brave and skilled and Armours have not the skill nor the tooling as most what they now sell is farmed out to other makers that'swhy Armours do not make Siamese pipes anymore they do not have the tooling and that'sthe answer you get if you ring them up, and they're only interested in the mass market and Not the odd one-offs yours Anna J