SBP 4 Stroke Shift Kit Grubee Gearbox

Discussion in 'Photos & Bicycle Builds' started by MotoMagz, Mar 26, 2010.

  1. MotoMagz

    MotoMagz Member




    012.jpg This kit is sweeeeeet! Makes the 4 stroke ride even better...higher speeds with less revs.and fun!Sick Bike Parts are great people to do biz with.You recieve quick answers to any questions you might have during your build.My build was easy and fun using this well thought out kit and mounting system.Take alook for your self

    Thanx Motomagz

  2. professor

    professor Active Member

    Those guys are really sharp - great design.
  3. Skyliner70cc

    Skyliner70cc Active Member

    Is this the gearbox that has the terrible noisey gear whine? Anybody know if this shiftkit can be used for other 4 strokes?

    Thanks, been looking for a 4 stroke shift kit for a while but not sure if this will work if it require using a noisey gearbox.
  4. Fabian

    Fabian Well-Known Member

    That SBP 4 stroke shift kit is a very professional looking design.

    If having a physically large engine in a pushbike isn't a problem with attracting attention from the police, it will prove to be a much better option from a reliability standpoint than the 2-stroke engine most of us are using now.

  5. MotoMagz

    MotoMagz Member

    I believe the kit will work with the hoot gearbox also..check in the vender area to be sure.As for whining I have none.My gearbox is a stage II.. quit and still running strong for over 3 years with all it original parts.

    thanx MotoMagz
  6. Skyliner70cc

    Skyliner70cc Active Member

    Where doesn't one buy a stage II? I've wanted a 4 stroke for so long but everything I read about the 4 stroke gearboxes were that they made a terrible whining noise.

    PS Anybody know if Hoot gearbox is good or not? Is Stage II gearbox a replacement for Hoot or vice versa?
  7. ocscully

    ocscully Member

    The stage II is/was the first improvement on the Orig. Grubee gearbox, and of all the Grubee gearboxes seems to be the quietest. Like Keith I was/am one of the testers and built using the Honda GXH50 motor with the Grubee III gearbox, mounted in a Schwinn Skyliner, and YES it is Noisey but getting a bit quieter as the miles build up. But I don't think it will ever be as quiet as the Stage II gearbox bike I sold to a friend last year.

    As for alternative gearboxes. The new DAX Duplex Chain Drive reduction box might be something to consider. Or perhaps the new Staton 5:1 Reduction box with inside drive. Both of these boxes are direct bolt up to the smaller 4-stroke motors that use the 76mm clutch (35cc Robin/Subaru, Honda GX35) and probably could be adapted to the current SBP 4-stroke Shift Kit.

  8. Stoney

    Stoney Member

    You can use the staton (18.75 gearbox) that is what zombie builder uses on his builds as well as others with the stretch frames
  9. Skyliner70cc

    Skyliner70cc Active Member

    Thanks! As much as I'm impressed with the 4 stroke shift kit, I will have to wait patiently until SBP doesn't their magic on better/alternative 4 stroke kits.
  10. MarksA-C

    MarksA-C New Member

    I wonder if that would work with the G4 belt kit. That would be an awesome combo!
  11. Ghost0

    Ghost0 Guest

    The 4G compatible design is in works.
  12. scottyo

    scottyo Member

    So what are your speeds like on the different inclines/declines/flats?
  13. MotoMagz

    MotoMagz Member

    My area is flat ..... have reached 30mph with the engine barley reving and lots of throttle to go.I might put her to the test soon.

  14. Irish John

    Irish John Guest

    Stage 2 is now out of production but Stage 3 is almost identical. They all whine - some not so bad but most are pretty noisy. You get used to it eventually. Putting the SBP kit on a hoot would be a waste of a good jackshaft kit on an inferior Hoot GB. The Hoot GB is the pits.
    I reckon you will soon have belt driven GBs available that will make the shifter kit unnecessary but the Grubee G4 will never be any good because it is too wide and wrongly geared (the new amended G4 is still wrongly geared) and the cover falls off because the holding brackets break. Think Grubee Stage 3 with SBP kit or EZM belt drive GB. Unless you rear mount the motor but that is a different scenario completely.
  15. MotoMagz

    MotoMagz Member

    I've been playing around with the gear ratios ..swopping out different rear freewheels and and just ordered a 10t sprocket from SBP.I clocked my self on a police portible radar trailer at 39 mph....thats about all I could handle! The kit has been problem free and a blast!

  16. Irish John

    Irish John Guest

    MotoMagz, where did you get that bike with the springer forks that have V-brakes on them and rear V-brakes as well? Great bike for motorising.
    Does the derailleur ever throw the chain off when changing up & down the gears and do you wear out the freewhelel cluster on rear wheel?
  17. MotoMagz

    MotoMagz Member

    Irish,The bike is a Schwinn Jaguar and I put an aftermarket springer with V brakes.
    As for the derailluer throwing the chain off it has never happend.I did switch my derailuer out for a higher quality so when shifting respones much quicker.The freewheel I just took of looks great with no signs of unusual wear.

  18. Irish John

    Irish John Guest

    Thanks for that info Moto, how good is the aftermarket V-brake on the springer? Does the Jaguar come with a V-brake on a rigid fork and if so is it the tapered steel standard Schwinn fork? If so that is a good twangy fork anyway.
    I really like seeing a cruiser without a coaster brake.
    Is it steel or alloy frame?
  19. Egor

    Egor Guest

    Moto I have the same gearbox and it was noisy also, I added hydraulic oil and that helped, I also looked inside and found that the gears were out of alignment also. I changed the shim on the clutch to move it out and meet the other gear better. I noticed you can loosen the back cover and move it around so I moved it closer to the clutch gear, it doesn't have a shoulder to locate on so if you move it closer to the front of the engine you get a better alignment. I also have all the shrouds off the engine and checked with a thermal scanner an found the engine stay cool, under 200 degrease, easy. And I like the look. I am going to cut the fins shorter on the flywheel so I can move the starter in closer. Have fun, Dave

    PS: I think your bikes look cool, good job. I like the new one with the Cog belt, it looks cool with the cover off, I love mechanical looks.
  20. Irish John

    Irish John Guest

    I think the Hoot gearboxes all break up inside because the gear wheels aren't properly hardened. The Grubee Stage 2 can be very noisy, just a bit noisy or relatively quiet depending on luck of the draw. Mostly they are noisy if they are more recently made models. The 11T freewheel teeth wear out after about 4000 kms. Getting replacements is difficult now that Grubee have moved on to the 4G gearbox. The Grubee Stage 2 is the best gearbox they have built so far by a country mile because it works well and replacing freewheels, clutch, bell housing and bushing is inexpensive if you can find a Grubee dealer who cares enough about service to stock the parts for their Stage 2 customers. A fixed drive sprocket will wear better than the freewheel because it is harder steel but the fixed sprocket is for a different shaft size and it is 10T which stuffs up the reduction ratio and thus creates a real problem further down the chain.
    The 4G is quieter because it is belt driven but the reduction ratio is ridiculously wrong for a 26" wheel and the GB is way too wide and looks pretty ugly.
    The Stage 2 is the best of the Grubees in my experience. I'd reckon if Staton make a GB it would be pretty good too but they don't make a frame mounted GB last time looked at their website.