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Dominator megaphone pipes - baffle solutions ??

Discussion in 'Norton Motorcycles (Modern)' started by Chris CSTM, Nov 14, 2019.

  1. Chris CSTM

    Chris CSTM

    Joined:
    May 7, 2019
    Hi guys
    I just received my Dominator (used almost new bike !!) superbe !!! Real beast !!!
    With its megaphone pipes... incredibly loud and not practical to ride in the city (until I can escape to the country side ...)
    For those who have megaphones how did you manage to damp the noise and make them slightly more reasonable ???
    fitted a baffle ? Any pictures solutions. ?
    thank you !
     
  2. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
    That’s a Sin. I ride my domi with open megaphones everywhere.
    But I know some on here have installed baffles.
    Congratulations on your new bike! She’s a beauty.
     
  3. Chris CSTM

    Chris CSTM

    Joined:
    May 7, 2019
    Thanks Voodooo
    Better than I would expect and look on the pictures. Really massive and compact. The essence of a motorcycle. Pure.
    The beast effect gets revealed at engine start. Willing to avoid any claim of my neighbours i really need to find a solution with noise reduction.... I have 3 to 4 km to reach open roads...
    Reducing from « Super load » to « Load » would be great ....
     
    Voodooo and TonyA like this.
  4. speirmoor

    speirmoor VIP MEMBER

    Joined:
    Apr 11, 2010
    Congrats! Where are the pictures, Post some up?
     
  5. TonyA

    TonyA

    Joined:
    Jan 16, 2015
    Baffles will have to be fabricated . Did you receive the road exhaust when you bought the bike ? I hope so. You can fit the Short loud mufflers , that may satisfy you until you can get the bike out of town. I have seen baffles fitted twice to the megaphones , both times it was fabricated and fitted with screws from the outside.
     
  6. TonyA

    TonyA

    Joined:
    Jan 16, 2015
    Like this I found on EBAY . This one has a 60mm O.D. DB Killer.png
     
  7. iwilson

    iwilson VIP MEMBER

    Joined:
    Nov 6, 2015
    I took a slightly extreme approach in having a local fabricator make a baffled replica set of megaphones. He improved on the factory design which is bolted directly onto the frame causing the bracket to work harden and eventually break. By using a rubber mount the pipes can flex enough to avoid this problem.

    [​IMG]

    They're still very loud and with the current engine mapping produce loads of pops and bangs on the over run.

    [​IMG]
     
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  8. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    I would keep a close eye on your headers iwilson, whilst rubber mounting the silencer end of the pipe can de a good idea, it can also transfer the stress point further along the pipe, as the back end is allowed to wobble a bit but the front end is still rigidly bolted to a rigidly mounted engine.
     
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  9. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
    Exactly.
    My megaphones are solid mounted. No a single issue.
     
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  10. iwilson

    iwilson VIP MEMBER

    Joined:
    Nov 6, 2015
    I've done about 4,000km on them and they look perfect. I know at least three Dominators in NZ have had their megaphone brackets snap. Makes sense when you look at any car exhaust system. Rigidly bolted to the engine but always hung off rubber mounts. First thing the fabricator said when he looked at how the megaphones mounted was that they'd eventually snap. He's been in the business for 40 years, but I'll keep an eye out.

    An example of his work below.

    [​IMG]

    This one I had fabricated for my Lotus when I did an engine transplant and was very tight for space. :cool:

    [​IMG]
     
  11. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Car engines are rubber mounted, that’s the difference. Rubber mounted engine + rubber mounted pipe = no stress.

    However, solid mounted engine + rubber mounted pipe = stress (somewhere, wherever the flex meets the rigid).

    If the head mounts and the pipes themselves are capable of withstanding the stress, you’ll be fine. If not, they’ll break.

    All I’m saying is, if it were mine, I’d keep my eye on it...
     
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  12. iwilson

    iwilson VIP MEMBER

    Joined:
    Nov 6, 2015
    Thanks Eddie, I suspect from an engineering perspective it’s a bit more complex with resonant frequencies and a host of other factors. Mine are still looking good (and I’d suggest I have more mileage than most Domi/megaphones owners). As I mentioned, in my neck of the woods it’s Norton 3 broken vs. rubber mounted 0 (he’d made 3 sets for other Domi owners last time I spoke with him).

    But I’ll be the first to put my hand up if they do break.
     
  13. TonyA

    TonyA

    Joined:
    Jan 16, 2015
    Norton 961 A Frames have the rubber bushing in them where the muffler brackets bolt on. Until the megaphones pile up the kind of miles that the Commandos do , I am with iwilson on this one. David C. has also rubber mounted the Domi Megas . They are dealing with more than vibration here , road bumps and flexing etc. Show me a solid mounted 961 Domi open megaphone system with 17,000 miles on it . I might believe then . Let the odometer speak for itself.
     
  14. TonyA

    TonyA

    Joined:
    Jan 16, 2015
    You have very low mileage .
     
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  15. TonyA

    TonyA

    Joined:
    Jan 16, 2015
    I can dream of a Norton 961 with a belt drive installed ! Imagine that , a dandy 961 with a no lube belt drive and no adjust hydraulic valves ! I wonder if that company that makes the Triumph pulleys would be willing to adapt something for the 961 ?
     
  16. Chris CSTM

    Chris CSTM

    Joined:
    May 7, 2019
    Hello guys.
    Regarding mounting with silent block or rigid. I will not comment full rubber bracket seems to flexible for me. Rather have a bushing type installés like on the commando long/short pipes installation just damp vibrations but keep pipe in position.
    however. My main issue is to find some inspiration / concept on the Baffles you have made for your megaphone and benefits you got in noise reduction . It will help me. thanks.
     
  17. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
    Correct.
    But I still don’t agree with a solid mounted engine and the use of rubber mounts.

    Like Eddie said, a production car has rubber mounted engine, trans and exhaust. Everything moves. On a solid mounted engine and rubber mounted exhaust, the exhaust will flex and move.
     
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  18. TonyA

    TonyA

    Joined:
    Jan 16, 2015

    I think you ought to forget about the bobber and look into that Superlight !
     
  19. TonyA

    TonyA

    Joined:
    Jan 16, 2015
    Do you think the sportster front belt pulley will fit the Norton 961 countershaft ?
     
  20. iwilson

    iwilson VIP MEMBER

    Joined:
    Nov 6, 2015
    It's one of those things that only mileage will answer. All I know is there are cases of the solid mounted megaphones breaking and none I'm aware of with the rubber mount breaking. I'm just offering my experience to date.

    Speaking of vibration, this is what happened to my clutch reservoir bracket after a couple of years!

    [​IMG]
     
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