Shakedown results - Exhaust

[Jdraper]

With time on my hands, I have been checking the parts book excessively.. As mine is a '55, this is a tricky thing.

My old exhaust pipe was supplied in the '70s and is well past its prime after my neglect, leaving it to rust in the open for 20 years. As the nut had rusted to the pipe, undoing it cause the stud to twist slightly, so I guess its now weaker.

My thoughts turn to replacing the pipe & silencer at some point, as the fit has never been good and fixing the pipe securely has always been a problem and remains so. The '55 parts book shows that the pipe is secured by a stud and 'Z' bracket. For 56, this has changed to a long stud/nut/bolt thingy - see pictures. Both pipes seem to be available, so which way to go? Opinions on this site & the suppliers seem to vary as to what is correct. My current one has a stud fitting, but I can't source a correct 'Z' bracket and the one I fitted is quite flimsy. I have sourced two of the stud/nut/bolt thingies, but they are different lengths - could the short one be for a twin?

In essence, when I get a new one, should I go for stud or bracket for the exhaust pipe? There must have been a reason for the change - better? Cheaper? Any thoughts?

Jeremy

[dave16mct]

I'd go for the Z bracket . You can make it easily, and then make it fit. The stud extension type rarely fits properly and hours of rat tail filing later...., often with a little extra bracket to connect the two!
Rob H had a '55 from almost new and says the Z bracket is correct.
Dave.

[Pharisee]

My '55 M18S has the "Z" bracket but I had to make it myself, which I did from a piece of 20mm x 3mm mild steel strip. I made up a 'template' from a piece of aluminium strip first to make sure I'd got the length, bends and holes correct before bending up and drilling the steel. I had thought about getting it chrome plated but in the end, it went to the powder coaters along with a load of other bits and pieces.

[adz25]

I have both setups. My 54 has a z bracket, as the others suggested just hand made out of 2mm mild steel and spray painted, easy to form and get to fit perfectly.

My 56 has the threaded spacer. Have to say it fitted perfectly with the armours pipe i bought. All assembled loosely to get the bolts to align then tightened all up with no fuss.

I guess its up to you which you prefer the look of and whether you want to manufacture your own z bracket.

[Rob Harknett]

The Z brackets job is to hold the pipe firmly rammed fully in the head. That's why slots are elongated. Pipe fitting and bracket must match. eg you must a pipe with the fitting for the Z bracket, with the Z bracket. or pipe with the fitting for the long chrome stud bracket etc. Note both types adjust via slots to hold to pipe firmly in the head. Note fix pipe tight first. Slide silencer on to line up with bracket and tighten clip.

[Jdraper]

Thanks for the prompt replies. I have been going through my library of pics from various open days in Kettering. Thumbs up if you recognise your bike! Looks like the issue generates lots of enginuity (!). Still undecided which way to go, but my workshop is minimal. Pipe stud & 'Z' bracket is clearly original, with a potential weakness that the stud could shear.

Any thoughts on what the short stud in my first post is from? The long one is clearly 56 and later.

Jeremy

[Mick D]

Any thoughts on what the short stud in my first post is from?

Hi

I think that's the standoff from a duplex framed bike - 026489

Regards Mick

[56G80S]

I use the long chrome thingy but still ended up with a length of flat mild steel in the mix between the end of the stud and the slot on the front pipe!

Johnny B

[Jdraper]

I installed the short chrome standoff and it could be a hybrid solution! The end of the standoff comes close to the stud fixing, meaning I could use a short, flat strip connector connecting the stud to the chrome stand off mount. Easier to fabricate, and would be better than my current flimsy arrangement. If I go down this route, I will post a picture.

Jeremy
PS this is what the bike looked like after too many years outside... Note my jubilee clip holding the pipe to the front down tube. And yes, that is the lower half of a baked bean can enclosing the speedo (from a Greeves). I was still in my teens in the 70's and knew no better...