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n15 gearbox sprocket

Discussion in 'Other Norton Motorcycles' started by andy63, Nov 17, 2018.

  1. andy63


    Mar 28, 2018
    hi all
    looking for recomendations on what people are running on gearbox sprocket for n15's.
    my 67 n15 has an 18tooth front and when riding at 50 to 60 mph the engine feels like its over revving.
    also whilst the primary is stripped down i was considering converting to belt drive primary,has anyone had any experience of fitting and where to purchase a well made system.
    thanks in advance.
  2. pierodn


    Nov 10, 2012
    I run my N15 with 20.
    I like to use the bike for long range.
    My G15 in restoration will have 21.
    My P11s all 19.
  3. andy63


    Mar 28, 2018
    hi piero.
    thanks for your answer.
    in all honesty i probably wont be doing long mileage trips on this bike but have felt that since buying the bike in march this year i havent been happy with the high revs at normal running speeds between 45-65 mph.
    now the bike is off road for winter i will now look to going up to 19 or 20 teeth as you have, and see if that helps,as long as i dont then start getting some bad vibrations with the atlas engine:(,my 99 dominator seems much more smoother but then the n15 is a bit of handful!!
  4. ludwig


    Aug 30, 2006
    Converting to a belt drive is one of the better mods you can do .
    I used a Commando primary case , with shorter an narrower inner and outer case .
    You will also need a Commando main shaft and do some machining .
    If you want to go that way , I can give you more details .


  5. pierodn


    Nov 10, 2012
    19 teeth is sure the best and fun for all norton 750 twins.
  6. NKN


    Mar 28, 2016
    Salut Ludwig, merci de continuer à nous éclairer de tes interventions lumineuses.
  7. robs ss

    robs ss VIP MEMBER

    Aug 16, 2016
    I used Commando primary cases on my Model 50/ES2 with NEB belt drive - I'm happy with the result.
    One penalty is that the gearbox moves too close to the engine to be able to retain the centre stand. The issue is position of the top spring mount not allowing the stand to go "over-centre" successfully.
    May not be an issue with N15s but something to watch for.
  8. ekkeneckepen


    Jul 5, 2015
    I used on my 750cc Atlas 21 teeth at the gear box and with belt drive 35/68 I have a total transmission ratio of 3.98 to 1. That's for my use good. I travel long distances in whole Europe and to reach the max top speed is not the goale. The engine revs by 100 km/h (the max allowed speed in Germany on non-motorways) with 3190 rpm.

  9. N0rt0nelectr@

    N0rt0nelectr@ VIP MEMBER

    Sep 15, 2014
    Does your N15 use a Commando timing cover? There is a breather where the mag or distributor goes.

    John in Texas

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