Grubee G4 kit mounted on Grubee bike with 1 piece crank

Discussion in '4-Stroke Engines' started by Irish John, Aug 20, 2009.

  1. Irish John

    Irish John Guest

    In Sydney today George Bushara, the Sydney Grubee dealer of "MBB IMPORTS' successfully mounted the new Grubee G4 kit on a Grubee GT1 cruiser. This might be a first for Australia!:jester: He had to tilt the tray a bit and mount it high and he used proper bolts and locnuts on the mounting tray but as long as you don't need the choke it's all hunky dory. The choke fits up between the 2 top tubes but can't be got at. It doesn't need the choke to start George says. These kits are the G4 gearboxes without engager. The stock exhaust vents out the right side. The bike isn't very pretty but it does work. It needs a 44T sprocket cos the 48T is too large and slow. The GT1 comes with a 44T that bolts onto the hub with 6 bolts. In many ways it's an improvement and in many ways it isn't. Pity really cos it didn't have to have the problems it has but the designers neither ride these things nor read our postings.
     

    Attached Files:

    Last edited by a moderator: Aug 20, 2009

  2. GearNut

    GearNut Active Member

    Ooooh 4G. I wannit!
    No darn gears that I keep reading about that are troublesome, and belts are quiet too.
    I soooo wanna build an IF 4-stroke, but I think I should wait untill these are available.
     
  3. Porkchop

    Porkchop Member

    Nice ! Where did you get the crank. ? I'm looking for one. Thanks !
     
  4. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Last edited: Aug 20, 2009
  5. Will Snow

    Will Snow Member

    Had the same problem with the choke, but I it would not fit at all. No frame tubes to go between, so I had to cut the coke shorter, drill a small into the the side of the material that was left. Screwed in a small rod and now I have a low choke lever that works fine.

    The gear case with the chain really sticls out to far for my liking, Is the belt drive closer to the engin I wonder.
     
  6. Irish John

    Irish John Guest

    You should post pictures of that choke Will. It might help other people.The belts are closer to the engine. You can see the belt in the picture next to the drive sprocket.
     
  7. Irish John

    Irish John Guest

    What is an IF 4stroke?
     
  8. glacknoid

    glacknoid Member

    Irish John: could you elaborate on the pro's and cons you've discovered so far. I was looking forward to the 4g becomeing available in the US for the Honda motor. Do you think it would work well in conjunction with a 4 stroke shift kit that SBP's is working on.
     
  9. glacknoid

    glacknoid Member

    Oh, I see you had to mount it so high because the crank isn't wide enough to miss the belt drive cuz it dips down so low. Maybe a wider 3 piece would work but then you would walk like you got off a horse after ridding it.
     
  10. glacknoid

    glacknoid Member

    John: you should fire it up and shoot some video to give us a little bigger taste of it in action other than that short video on youtube.
     
  11. glacknoid

    glacknoid Member

    John: I have the three piece crank I got with my stage 3 grubee gearbox and the crank arms that came with it are about an inch shorter than the one piece like yours from the same place so that would give you another inch which may make the choke accessable
     
  12. Irish John

    Irish John Guest

    The 4G doesn't fit a Honda because of the bolt-on to engine configuration. I also think that there is no reason for a 4-stroke shifter kit because they work fine without it. The guys with the NuVinci hubs & 4 stroke frame mounts don''t seem to get much advantage except they can follow a hearse up a very steep hill where the rest of us with single speed GBs would have to go faster to keep the motor in its power band. Shifter kits make sense on the HT motors because they might prolong their very short life by a certain amount but even then it is making a silk purse from a sows ear.
    The question with this 4G is what sprocket to use because the 48T is too large. I'm using a 44T but haven't got it built yet. It certainly won't be too small a sprocket but it could be too large.
    That's all I can tell you right now. Don Grube is working on custom made 3 piece cranks to fit this GB so they can take cruiser BBs and pedals and have normal length crank arms.
    If you read this Forum Glacknoid you'll see that the single speed GB is fine on a frame mounted 4-stroke a shifter kit is just added complication for no real gain in my opinion.
     
  13. Irish John

    Irish John Guest

    It would but I don't like the cadence of the short stumpy crank arms. I would mount it higher and use the 1 piece until the special 3 piece is available.
     
  14. Will Snow

    Will Snow Member

    Irish John;227233]You should post pictures of that choke Will. It might help other people.The belts are closer to the engine. You can see the belt in the picture next to the drive sprocket

    When I get it finished I will post some pictures and explain what I have done.

    I had looked at the picture and thought the belt drive looked more narrow.

    Thank you for the clear information and the nice pictures. I found it interesting.
     
  15. glacknoid

    glacknoid Member

    Ya, I've been getting along ok with my stage 3 grubee single speed but I always wear my headphones cuz the noise, though it's not as loud as it used to be it's still annoying, that's why I'm anxious to get one that's quiet and has a little more low end but with a potential to get up to a decent speed, that's what the shift kit would be nice for more low and high end gear range. Firebelly has a nice looking transmission but I want to compare and decide between it and the 4g.
     
    Last edited: Aug 22, 2009
  16. glacknoid

    glacknoid Member

    I heard Don Grubee is comeing out with one for the honda and the prototype would be done in a few months. There's even some parts for the honda featured on his web site.
     
  17. Irish John

    Irish John Guest

    What do you mean "more range" Glacknoid? My Mark2 Grubee goes 280 kms between fuel stops. How will a jackshaft & gears improve your range?
     
  18. Irish John

    Irish John Guest

  19. glacknoid

    glacknoid Member

    IrishJohn: No, not mpg, I meant range pertaining to the gears, low end for steep starts and high for more speed on the flats without haveing the motor wound up all the way.
     
  20. mmachine

    mmachine Member

    IrishJohn

    What is the width of the belt?
     
Loading...