Grubee 4G T-Belt and SBP shift kit?

Discussion in '4-Stroke Engines' started by Tarvarno, Jun 20, 2012.

  1. Tarvarno

    Tarvarno New Member

    Hey folks,

    Can someone tell me if kits using the Grubee 4G T-Belt drive are compatible with the SBP 4 stroke shift kit? The info on their site only specifically says that they are compatible with Hoot or Grubee stage 2 or 3 gearboxes.

  2. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    SBP or for those that don't belong to the inside club
    should update their info as the Grubee 4G T-Belt drive that fits on the
    Honda or Huasheng 5/8" shaft does work with their shift kit.

    Several members here are successfully running that combo including
    my good buddy The_Aleman

    The Grubee 4G T-Belt drive is the ONLY gearbox I and many others here
    would recommend using with SickBikeParts excellent shift kit.
  3. Tarvarno

    Tarvarno New Member

    This is exactly the answer I was hoping for. Thank you very much!
  4. The_Aleman

    The_Aleman Active Member

    The version of 4G for the "5/8 shaft" Huasheng is pretty much a bolt-on for the SBP 4-stroke shift kit. The pedals will just clear the 4G with cover mounted.

    The other 4G will be significantly wider, might need to modify crank arms or use shorter ones.
  5. Tarvarno

    Tarvarno New Member

    The 5/8 inch shaft is the one I'm looking at, so that's good news. I have a question about this failure-prone one-way bearing I keep reading about. Apparently it's rather problematic. Is there a standard replacement part that I should be looking at?
  6. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Cheapest and easiest fix is to get it welded solid.
    Some people have made them solid with JB weld.
    One guy made a solid metal replacement.
  7. The_Aleman

    The_Aleman Active Member

    Yeah, I don't have any experience with the one-way bearings. My 4G is a 2010 model, 5:1 with 11T freewheel sprocket.

    From what I've read it doesn't seem too hard to make that bearing non-freewheeling.
  8. MotoMagz

    MotoMagz Member

    Neil I thought you were talking about me when you said a good buddy with a 4g and the shift
    I am very happy with this set will like it!
  9. astro83ve

    astro83ve New Member

    Hello Everyone, I know this is most probably the wrong place to ask, but I have installed on bicycle a 4g huasheng 142f with a sick bike parts shifter kit for it. However I have a problem that the rear wheel goes out of alignment due to the torque from the engine. Is there a heavy duty rear wheel axle in order to fix this problem, I replaced the rear wheel hub axle last weekend, and the wheel was straight, now less than a week later the wheel is already beginning to graze against the left side of the frame. Help!
  10. The_Aleman

    The_Aleman Active Member

    You will probably need axle adjusters to keep your wheel in place. Can you post a picture of your dropouts?
  11. astro83ve

    astro83ve New Member

    100_4347.jpg 100_4353.jpg 100_4354.jpg

    Hopefully, you can see in the pictures the leaning of the wheel, thank you Aleman, other people have also recommended that, however the hub axle isnt moving out of place, what actually happens is that it gets twisted inside the hub. If can help me out that would be great with any ideas, or if you need better angles please let me know. I really want to get it working the best I can.
  12. The_Aleman

    The_Aleman Active Member

    I don't know what you mean by "it gets twisted inside the hub". That would mean your bearings or chainstays are at fault. The hub axle moving on the gear side is much more likely.

    Most frames these days have "semi-horizontal front-exit" dropouts. These kind of dropouts can allow an axle to move on the gear-side. Vertical dropouts won't, and "horizontal rear-exit" dropouts have quite a few axle adjusters available to keep the axle in place. There are a few for the front-exits, too. What I need is a picture of your dropouts.

    Example, here's my bike with rear-exit dropouts and axle adjusters. Before I installed the adjusters, I had the same problem you did:

    Axle adjuster.jpg

    So either your axle is slipping on the RHS or your frame is bending at the chainstays. Maybe your frame is already bent.
    Axle adjusters are inexpensive and will likely solve your issue.
  13. Barry

    Barry Member

    My JB Weld fix for the one-way bearing just failed me at the 30 mile mark. Ordered a new one tonight and plan on REALLY welding it when it comes in..
  14. tom-fishing

    tom-fishing Member


    Are you using a cro-molly axle? Some of the stock axles are really pretty soft steel. I'd try a harder one and make sure your bearing cones are not over tightened or to loose. You want to have no slop and still roll freely. Good luck!