Calling all Honda 4 strokes with Grubee Gearbox

Discussion in 'Frame Mounted Engines' started by sexwaxsurfer15, Jul 6, 2008.

  1. I have a Honda 50 cc with the Grubee gearbox with a 56 tooth sprocket. I was wondering if anyone out there has the same setup but with a 44-36 tooth sprocket. My top speed now is around 32mph(full throttle). I would like to be able to cruise at 35(not reving the engine way up), with decent low end:grin:. Can someone let me know what sprocket I will need to do this? Thanks


    RATRODER Guest

    This is for Bicycle repair&mod!
    Please post your motor stuff in the proper forum! louis
  3. loquin

    loquin Active Member

    It's probably not a Honda engine, either...
  4. what does that mean?
  5. Zev0

    Zev0 Member

    I don't think it belongs in bicycle repair either. That area is for unmotorized bikes I thought. Hmmm where does it belong?
  6. loquin

    loquin Active Member

    If this was a Grubee kit, the 4-cycle engine that he provides is NOT a Honda. It's a Chinese clone. I'm not even sure if the bolt-pattern on the clone is the same as the genuine Honda. There's consistent chatter that the grubee engine was "designed by Honda." Probably a closer to reality statement of actual events is along the lines that the Honda engine was reverse engineered by the Chinese manufacturers, and is being sold by them as a knock-off, with no money ever being given to Honda for their engine design. So, not only did they lift the design, they're using Honda's name, too...

    sexwaxsurfer15 - is this a frame mount, or a rack mount?
    Last edited: Jul 7, 2008
  7. I bought the engine separate from Frame mount
  8. MasterLink

    MasterLink Member

    well to get to your post i have the same set up on a 48 tooth get in about 35 mph with no governor the motor is at high rpm's. lgoin what is the point telling evryone that they don't have a Honda mine is stamped in the case in aluminum razed letters HONDA
    the dude has like 10 post :shock:
  9. cruiser66

    cruiser66 Guest

    Have to agree with Masterlink. The Grubee gearbox can be used with either a Honda or HuaSheng 142FG. They both have the same diameter output shaft and mounting bolt pattern. The Honda has a little more power and can give you a little more speed under the same circumstances.

  10. honda and gear ratio

    i had the 56 tooth on my honda and topped out at about 30 mph, but can hit 35 consistently on flats with my 48 tooth (almost 40 if i do #1 and 2 before i ride). sexwax, why dont you put on the smaller than 48 and tell us what happens...kind of seams like its too small, like you will rev out your motor, but i have never tried it. just remember, the pistons are right below your jaw, so if they pop out it could be bad.
  11. jimraysr

    jimraysr Member

    I agree that the bolt pattern should be the same for both Honda and the China knockoff.

    The instructions goes into detail about how one bolt may be to high on the China engine and might have to be filed down for the GruBee gear box to seat properly.

  12. rjones

    rjones New Member

    I have a 44T with grubee gearbox and honda engine. My bike tops out on the flat at 38 mph. (190 lb. rider). The 44 is too high for me. I live in the mountains. I would be glad to trade it for a 56T. It's a heavy duty chrome plated 44T sprocket from If you're interested email me at
  13. Irish John

    Irish John Guest

    You need a 48T which is available from any HT supplier. A 50T is better but harder to get. A 44T is a total waste of time but you will hit 63 km\hr on the flat until a light headwind stops you dead. A 38T is one I haven't tried but I can tell you that you'll be pushing the bike up every small incline. The smaller the sprocket the higher the speed that the engine will judder at. People who talk of 44T with this kit either live in a State which is all downhill or they are spinning a yarn. 48T is OK but some hills are a struggle. 50T is better. 56T is all high revs, vibration ad low top speed. These kits should never have been supplied with 56Ts cos they are at least 4 sprockets too big. The answer to your question is you can't cruise at 35mph and have any low end. ipso facto! Sorry to disappoint you. You can cruise at 29 mph and have OK low end on a 50T. You can even go faster but you'll wreck the motor at those high revs over a distance.
    Last edited by a moderator: Jul 26, 2008
  14. I live in south Florida. FLAT!!!
  15. Irish John

    Irish John Guest

    If it is totally flat you could try a 44T and as long as you aren't stopping and starting and there aren't traffic lights etc. Anything smaller than a 44T would really give you the judders starting off and the engine would labour very hard at speeds up to about 18 mph. Starting off is the bit that hurts the motor - like driving off in a small car in 4th gear only instead of stalling like a car you can sort of pedal your way through it and listen to the clutch juddering. In one of your hurricanes you'll probably be OK downwind but upwind you'll just stall. Where I live there is one flat road - the highway north and sometimes use the 44T on that and pray I don't encounter headwinds. It's great fun and I laugh at the speed but it does attract attention and one day possibly police attention so I don't use the 44T often. Motor assisted bikes aren't supposed to go that fast over here.

  16. I weigh 150 lb.; does that make a difference?
  17. Irish John

    Irish John Guest

    It certainly does. I think on the flat a 44T would be OK but not for frequent stop starts but occasional ones would be fine. I weighed 189 lbs when I tried mine and I hit 63 km\hr or just over 39mph on the flat when the motor was brand new but i had trouble later with headwinds. At 150 lbs you will probably go really well but going down to the 36 or 38T sprocket will probably make it impossible for you - the engine won't hit its power band unti it's doing a faster speed which means it will struggle hard at speeds below that. I have no traffic stops near me so I can zing along undisturbed except for hills. On the 44T I couldn't use shared cycle paths cos I had to keep the speed up to a comfortable 30 km\hr minimum which is too fast for other path users. The 44T was great on the freeway cos we have a hard shoulder marked for cycles only and its one-way only. Yep I think 44T will do you nicely and you might even get down to a 40T if you can find one - if you have uninterupted journeys your motor will probably use less fuel and will rev much lower. If you can keep your speed up you'll not hurt the clutch. You'll know how far you can go down in sprocket size after a while but I think 44T is the best for you. I am happy using a 48T and I don't mind hard pedalling on hills cos I need some exercise. Here's what my bike looked like with 3 different sprocket sizes.

    Attached Files:

  18. Emmased

    Emmased New Member

    35 MPH on a bike? Don't get me wrong. I've done it and it's kinda fun for a while but frankly I think that's too fast to be safe. After a while, it's exhausting trying to dodge potholes and not get nicked by a passing car. It's also a lot of hard work on the motor and the bike parts. I found once I started cruising at 20 or so I could commute almost as fast and my repaiers were fewer and further in between.
  19. Irish John

    Irish John Guest

    On your Grubee GB with its 11T drive sprocket you'll find the 48T better than the 56T. I've tried 56T, 48T and 44t. 44T is a waste of time unless you live in a totally flat area with no wind. 48T is better than 56T. 56T revs too high on the flat. 50T is probably best. My HS motor will do 52 km\hr with a 48T and I did 65 km\hr on the flat with the 44T but it couldn't climb small hills. The golden rule is that the smaller the sprocket you use the higher the speed at which the motor will judder and run out of steam. Kings Motorbikes have 50T sprockets but they don't answer the phone cos it's an interuption to their work (no kidding that's what the ansaphone tells you) and they don't answer emails except on one day each leap year. Go with the 48 and pedal harder on hills. It's better for the motor than reving the guts out on the 56T. The reason they sell the kit with a 56T is because the guys who put the kits together only drive cars.
  20. Duhawki

    Duhawki New Member

    Where can I get a Grubee gearbox? I found the manufacturer's website, but the Montana distributor listed does not seem to engage in this type business.