I have been using "S" pipes for years and am not sure of the correct mounting of the pipes to the L bracket at the rear. I use two short lengths of chrome steel to attach to the L bracket as per what I can determine from the parts book but my L bracket has four holes instead of two and my pipes are very close to the primary cover in comparison to the pipes in the other "S" topic as per dog-t's restoration. Does anyone have a photo that might help? thanks.
"S" pipes
- Thread starter katescottageiom
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DogT
VIP MEMBER
Maybe I should explain a bit more. The picture does not show but a small part of the metal bracket that attaches outside the chrome bracket but the hole spacing is the same as the chrome bracket. It holds the pipes together. Google S exhaust and you should find some good info. Others have modified the mounting so it is not so locked into place. After a while, the shields will crack and come off (and you will remove them because you want to). You can ride the bike without the shields if you are careful not to burn your legs, I did this for many years. If you have 4 holes, someone must have drilled some extra ones. Believe me, it is not a good mounting of the exhaust. I'll see if I can find the alternative mounting and post it later.
DogT
70S
DogT
70S
DogT
VIP MEMBER
I found it. Maybe this will help.
"I had a problem with my exhaust mount rubbers shearing after low mileage after I mounted a set of "S" pipes on my '70 Roadster. The original design of the rear mount looks too weak to me with just two rubber mounts holding both pipes. I worked up a new mounting system as follows: I used two stud-bolts (I used 2 Norton P/N 06-4688 studs (5/16x24) I had lying around) threaded one each into the mounting bosses on the two mufflers, then installed the flat bracket that holds the two mufflers together, then secured these brackets to the mufflers with backing nuts making a rigid assembly of the two mufflers. I then made a "sandwich" of rubber isolators over the two studs using a combination of Norton tank mounting rubber washers (06-0648) and drilled-out center rubbers from the original rubber mountings. Then fit the ends of the studs through the chrome "L" bracket with more rubber washers on the far side (need smaller OD washers here to fit inside the "U" shape - had to go search the hardware store to find some), then secured with flat washers and self-locking nuts.
This has worked well so far; the two stud bolts provide more strength for vertical shear forces from the weight of the mufflers. I have been careful not to tighten the lock-nuts too tight and not over- compress the rubber "sandwich" as the exhaust system needs some flexibility to vibrate with the engine independently of the frame.
This needs to be tight to keep the support, just not too tight. Hope this helps."
I don't know who posted this or where it came from but it sounded pretty good.
DogT
70S
"I had a problem with my exhaust mount rubbers shearing after low mileage after I mounted a set of "S" pipes on my '70 Roadster. The original design of the rear mount looks too weak to me with just two rubber mounts holding both pipes. I worked up a new mounting system as follows: I used two stud-bolts (I used 2 Norton P/N 06-4688 studs (5/16x24) I had lying around) threaded one each into the mounting bosses on the two mufflers, then installed the flat bracket that holds the two mufflers together, then secured these brackets to the mufflers with backing nuts making a rigid assembly of the two mufflers. I then made a "sandwich" of rubber isolators over the two studs using a combination of Norton tank mounting rubber washers (06-0648) and drilled-out center rubbers from the original rubber mountings. Then fit the ends of the studs through the chrome "L" bracket with more rubber washers on the far side (need smaller OD washers here to fit inside the "U" shape - had to go search the hardware store to find some), then secured with flat washers and self-locking nuts.
This has worked well so far; the two stud bolts provide more strength for vertical shear forces from the weight of the mufflers. I have been careful not to tighten the lock-nuts too tight and not over- compress the rubber "sandwich" as the exhaust system needs some flexibility to vibrate with the engine independently of the frame.
This needs to be tight to keep the support, just not too tight. Hope this helps."
I don't know who posted this or where it came from but it sounded pretty good.
DogT
70S
- Status