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Who would buy one of these AMC gearbox clutch centers?

Discussion in 'General Classic Motorcycle Discussion' started by beng, Feb 17, 2012.

  1. batrider

    batrider

    Joined:
    Aug 9, 2008
    Am I understanding correctly that there is very little or no engine braking by design with this type of clutch? I think I would miss that.
     
  2. beng

    beng

    Joined:
    Jan 21, 2011
    The engine braking works fine with this clutch, it is just the sort of extreme engine braking that would lock up a rear wheel, or downshifting into first going down a steep grade that will make it slip.

    It never slipped on me just doing the normal fourth to third to second to first downshifting at legal speeds.
     
  3. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
    Am I to understand that only the clutch inner has a spiral, and the outer clutch case have straight cut slots, as per normal? :?:
     
  4. beng

    beng

    Joined:
    Jan 21, 2011
    The only part you would be replacing is the clutch inner drum itself, that single part. All the rest of the parts would be stock Norton parts.

    Ideally I suppose an angle could be put into both the inner and outer drums, but it has been shown to not be necessary and would just be more cost and more to manufacture.
     
  5. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    But there might be a benefit to angle the clutch plate tines?
     
  6. beng

    beng

    Joined:
    Jan 21, 2011
    Heinz Kegler, because an infinite number of factory servo clutch inner drums was not available and in fact limited to a handful, found it easy to take a regular clutch outer drum and grind an angle into it. In fact he offered this service along with his work on brakes, setting up clutches and manufacturing his swingarm collars.

    Because the torque is not the same as it is at the outer drum far away from the center as it is closer to the center of the clutch, putting the same angle in would help but might not have as much servo effect.
    Heinz said it took a lot of trial and error to get the exact right angle for the inner drum, too much and it would not release, too little and it would not clamp hard enough.

    I talked to one 650ss rider who had installed one of Heinz' re-ground clutch outer drums and he said it did help him use less spring pressure to get satisfactory performance from it.

    Of course opening up the slots to an angle means they will be wider at one end than the other, but they naturally line up against the side that drives them so it is not an issue, they are not rattling back and forth causing any trouble.

    If someone is patient laying it out and altering it either with hand or machine tools, it might be a nice project for the bored Dominator enthusiast with an extra clutch laying around to play with.
     
  7. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
    Re;
    "Of course opening up the slots to an angle means they will be wider at one end than the other, but they naturally line up against the side that drives them so it is not an issue, they are not rattling back and forth causing any trouble."

    :?: :?:
    Sorry, but I have to question this, as from the photo at the beginning of this page it is not a modified standard clutch centre, or the angle would break into the already straight cut groves/slots :?: :?:

    Do you happened to know what the angle of this clutch centre is, as per picture :?: :D
     
  8. bwolfie

    bwolfie VIP MEMBER

    Joined:
    Sep 21, 2010
    It os a new part, the angle is spelled out in the article I posted, something like 1 thread per 37".
     
  9. hobot

    hobot

    Joined:
    Oct 19, 2005
    Count me in on one for under $100, kewl.
     
  10. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
    Some of you bikers obliviously still live in the 1960s :!: :D

    those were the days, but they have ..........gone :!:
     

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