Regarding the finding of suitable cross-over tubes. I have no idea what the "stock" diameter is all of the airheads in our posession having been switched to after market stainless steel systems more than 30 years ago (R65/80 and R100) and a stainless steel system was fitted to the 1984 R65 when I bought it in 1995.
The reason for the long preamble is acknowledge that I know nothing about the measurements of the stock exhaust system.
But, all three of our bikes are fitted with "Staintune" systems, an Australian manufacturer universally regarded as making a 1st class (if hideously expensive) system.
All three bikes use 1" internal diameter tubing for the cross overs - given this uniformity across a fair number of years I am inclined to think that Staintune copied the stock measurement.
The above thought it reinforced by how difficult 1" ID drawn seamless tube is to find, I very much doubt that they would have used it unless they felt they had to.
If in fact you do need 1"ID tube you will find that it is a not a standard "shelf item" at your local steel supplier and that you will probably have to buy a 3 or 4 metre length of it as a special order.
There is however a possibility of avoiding that.
Your local brake rebuilder will likely have 1" ID tube in stock as it was a popular size for brake wheel cylinders and also certain truck master cylinders. They may be willing to sell you an offcut in the length required.
If not, do what I did - buy the 3 metre length and then contact all the brake rebuilders within a reasonable radius and ask them if they would like to buy some from you. I still have 750mm left and am cashflow positive on the whole saga of buying 1" ID stainless steel tube, but id did take a while and I haven't included my time in that of course.
I'd also like to comment on preparing the nice new tube for service on your bike.
Firstly polish the mating surface on both the new pipe and the old "spigots" on your exhaust pipes - you are aiming for a reasonably "easy" slip fit.
Secondly, measure the insertion depth - this is important.
Thirdly, put two brand new blades side-by-side on your hacksaw frame (I used 32 TPI).
Fourthly, clamp the new cross over tube securely and mark a point at least 1/8" less than the insertion depth (otherwise you are going to have "tick, tick, tick" exhaust leaks that will drive you spare - believe me I know.)
Fifthly - stop, go to your local hose shop with your cross over pipe and buy two stainless steel hose clamps of the type that are a full circle and use a bolt to provide tension.
Sixth, go home and carefully and accurately cut two slots in the tube ends using your modified hacksaw and ensuring that you cut no further than the previously marked lines.
Seventh, de-burr the slots you just cut - a dremel or similar tool is a godsend for this.
Eight - Liberally coat the mating surfaces with copper anti-seize and assemble your exhaust.
Ninth - Drink beer and congratulate yourself, unless of course you are a friend of Bill in which event you have a few more steps to follow.
Do not under any circumstances believe the blandishments that may be offered by sellers of exhaust tubing. Stainless steel exhaust pipe is a truly crappy grade of stainless steel and it is also a seamed pipe. You will not be able to polish it and worse, due to the seam it will not fit on the spigots if in fact you are lucky enough to find any in 1" ID (it does exist but according to Bluescope Steel where I buy my steel, it has not been made for many years.
Topic: Junction between the two exhaust pipes... useful ? (Read 1581 times)