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triumph 650 5 speed conversion

Discussion in 'Triumph (Classic)' started by britbike220, Nov 1, 2010.

  1. britbike220

    britbike220

    Joined:
    Aug 6, 2005
    Has anyone converted a 650 4 speed to a 5 speed gearbox? I have a complete 5 speed clutster and am thinking of going to a 5 speed on my 70 tiger.
     
  2. prmurat

    prmurat

    Joined:
    Jun 6, 2003
    I think it is like in my 69 Trident..just drop in there!
    philippe
     
  3. britbike220

    britbike220

    Joined:
    Aug 6, 2005
    I thought there were a few variations of the 5 speed and am unsure if they all fit the same or of modifications would need to be done, thanks Phillipe.
     
  4. tricatcent

    tricatcent

    Joined:
    Jul 30, 2009
    I have done this a few times before. It is pretty easy to do. The Triumph 5 speed is a nice gear box. 1st is slightly lower so you can run taller gearing so that the engine doesn't need to run as fast on the highway. The gears shift easier on the 5 speed, because each gear is closer to the other gears. There is less of a jump between gears. These gears also fit into the pre unit gearbox shell. I have seen Nortons running a Triumph pre unit box with the 5 speed conversion. You will need to open out a hole in the inner cover. This is only for clearance so it can be done with a file or die grinder. The important thing to get right is the movement of the gear lever. The gear lever on the 5 speed moves through less of an angle than the 4 speed. This is done on the bikes that come from the factory with a 5 speed by having the outer cover machined differently so that the gear lever moves less. You can modify your outer cover. The simplist thing is to get a 5 speed outer cover.

    if you don't do something to limit the gear lever travel you will shift from one gear to a false neutral between the next two gears intead of the way it should work. You don't want that. I think I know this from doing it the wrong way the first time. That was a long time ago so I can't remember it that well any more.
     
  5. norbsa48503

    norbsa48503

    Joined:
    Apr 7, 2004
    Yes that is very true the whole shift mechanism inner and outer covers are different and not by anything you could see with the eye. All of the 5 speed bits need to be there re- mounted into the covers. The new bits will fit the pre-unit as well. Little .020 differences in little parts make huge differences in the distance of each shift.
    Another thing about this each gear has a set of part #'s punched into their sides be sure you are not using a cast off set of gears from the early bikes with straight dogs or you will be very disappointed with the box.
     
  6. britbike220

    britbike220

    Joined:
    Aug 6, 2005
    That is excellent to know. I'll start looking for a late model cover, thanks for the heads up.
     
  7. pdl999

    pdl999

    Joined:
    Nov 11, 2010
    Take a look at triplecycles.co.uk under "written articles" where you will find some very good info on 4 to 5 speed conversion.
     

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