New ratio 4G gearbox from Grubee

Discussion in 'Frame Mounted Engines' started by Irish John, Feb 22, 2010.

  1. Irish John

    Irish John Guest

    The attached is a message from Don Grube. My query is given that the large pulley wheel in the old 4G was way too large and consequently the drive to the rear wheel was all wrong will this one get it right? The maths guys on this forum will surely know whether this GB will work adequately like the Mark2& Mark3 gearboxes did with an 11T chain sprocket to a 48T rear wheel sprocket on a 26" wheel? I'm worried that the reduction in size of the rear pulley wheel will be diminished by the reduction of the chain sprocket from 11T to 10T.
    Don's Message:
    These pics. will be posted on our grubeeinc.com web site in 4G 4 cycle section in the coming weeks; By viewing now you can have first look see at the new 2010 4G upgraded transmission with one-way brg. 80T pulley and 10T soild drive.


    FYI: A conversion kit will take a 2009 model to 2010 specs. with a simple shaft and pulley change.

    The new 2010 4G PL/PO form has all items listed. Please acknowledge if interested.

    Cheers:
    Don and Angel China GAS
    1 (2).jpg

    4G 20T-80T-10T-50T.jpg

    #1. _4G upgrade.jpg
    Don's reply to my query that the ratio being wrong again:
    You can have choice of 36T, 44T, 48T or 50T rear wheel sprockets. Now do the math. with a 4 to1 trans. ratio and 10T chain drive sprocket. You worry to much. Cheers Don
    My answer is I don't know but if he lent me one for 2 weeks I'd be able to tell him what rear sprocket size, if any, it works best with. I do worry I suppose because of my experiences with the first 4G which was documented elsewhere last August.
     
    Last edited by a moderator: Feb 22, 2010

  2. tjs323626

    tjs323626 Member

    I just looked at this and the figures that Don Grube has listed for the ratios are incorrect. It actually is 20 to 1 not 9 to 1. Several sprockets were mentioned.

    The 36 tooth ratio is 14.4 to 1
    the 44 tooth ratio is 17.6 to 1
    the 48 tooth ratio is 19.2 to 1
    the 50 tooth ratio is 20 to 1

    Just thought I would point this out to be helpful.

    Tom
     
  3. Irish John

    Irish John Guest

    You're right. He adds the ratios instead of multiplying them.
     
  4. abikerider

    abikerider Member

    I wonder if the cover will be smaller as well. That could help with the crank to transmission clearance.
     
  5. Irish John

    Irish John Guest

    I doubt he'll change the flimsy bracket that breaks off from vibration or the plastic cover so we'll have to wait and see but I'm certainly not interested in it until he gets the reduction ratio right which, at present, he hasn't. The gain on reducing the pulley wheel size (still looks too big) will be diminished by the decrease in the drive sprocket from 11T to 10T. Why doesn't he just post a thread and ask?
    Has anyone found the G4 useable? if so how have they made it useable?
     
  6. HseLoMein

    HseLoMein Member

    Hey Irish,

    I have the 2009 version of the 4G belt drive, i can tell you right now that the 5:1 ratio gear box with the 5:1 ratio for the rear sprocket, for an overall reduction of 25:1 is very useful. I went on a rally this past weekend and i had no problems keeping up or passing people. and now i can acutually get up hills. I will get a speedo this weekend and i will have numbers for you later.
     
  7. Irish John

    Irish John Guest

    That's interesting HseLoMein but you need to supply info like G4 GB with 11T freewheel drive sprocket to 44T rear sprocket on 26" wheel for your information to become really useful. A good picture (left side) always helps as does the mileage you have covered since the install. You are the first happy customer I've read about because I can tell you that the early G4 I built was unuseable as Sean, the owner, attested elsewhere on this Forum. Your set up must be different. It never performed well because of the gearing but the increased torque pulled the 11T freewheels to bits - the 11T freewheels for the G4 are not the same bolt fitting as the 11T freewheels for the older Mark2 & Mark3 GBs incidentally.
     
  8. another happy 4G owner

    my setup is the honda 4G drive which is thinner than the Hausheng 4G drive. I'm running a 48t rear free wheel sprocket,and it has the 11t free wheel[I know 2 free wheels] Would like to try the 44t sprocket but can;t find one. The so called flimsy brackets on my unit are actually pretty stout.I now have over 200 trouble free miles on my 4G. 30mph top speed with plenty of torque to make it up hills. Very happy with the 4G
     
  9. Irish John

    Irish John Guest

    That's good to hear Bill. How much thinner is the Honda 4G? A 44T sprocket is available from any 2-stroke kit vendor (at least they are here) because that is what they mostly use on 48cc & 66cc kits. Has the freewheel pulled the ratchet through the pawls yet?
    Are there photos posted anywhere of your bike because I'd love to have a look?
    200 miles is only 90 miles more than I include as the trial period before I hand a bike over to a customer and sign off on it but most serious defects should have become evident by this distance.
     
  10. photos of my 4G huffy cranbrook

    I have photos of my 4G at below links
    http://www.motoredbikes.com/showthread.php?t=26544

    and

    http://www.motoredbikes.com/showthread.php?t=26376
     
  11. No not yet. My stage 111 sure did after a short ride. Seems like the brass colored 4G version might be a little more stout than the silver colored more flimsy looking stage 111 11t free wheel
     
  12. Irish John

    Irish John Guest

    Why is the Honda G4 thinner than the HS G4? You don't explain this Bill and I can't understand how it is thinner. Your bike shows a HuaSheng motor. My total experience with the HS/G4 was that it was near impossible to builg using a GT1 Grubee cruiser and that it was unuseable when built because of the repeated 11T freewheel failures. The owner still can't use it 8 months later. It is also totally too wide and isn't a good ride even if it was rideable.
    Yours looks rideable but 200 miles isn't really a serious distance to talk about.
    I rebuild every 11T freewheel I get using red loctite on the flanges and letting that cure for 48 hrs but on the G4 it didn't help.
    Just talking about it again makes me feel depressed and angry because what I wrote about the G4 and the GT1 cruiser on threads at the time seems to have been proven true and I reckon the "new improved g4" will be just as bad.
    I notice yours has different brackets for jholding the cover on and on the one in the pictures we changed the crank to 3 piece wide and lowered the motor but it was still a piece of total garbage compared to the noisy old mark 2 GB which at least works properly and is correctly geared even if you have to chuck out the 56T and get a 48,50 or 52T to get the gearing right.
     

    Attached Files:

  13. Recumbentbill's 4G is narrower because it doesnt have the domed clutch cover like the usual HS 4G ....Id like to know how this works , Bills 4G is at least an inch narrower .
     
    Last edited: Apr 15, 2010
  14. Irish John

    Irish John Guest

    And it's a HS motor as well Simon not a Honda. Wonder could you use that GB instead of the one you have. I think the bolt holes were made differently for that model so the HS motor will be different too.
    How utterly idiotic is that?! Well done Grubee!
     
  15. abikerider

    abikerider Member

    Hey recumbentbill, did you have to drill new mounting holes on the G4 to fit on the Huasheng? Any special modifications? If not, then why would anyone use the G4 designed for the Huasheng when they could use the thinner Honda one? It sounds like the Huasheng shipped with the G4 as a package has different mounting holes than previous Huashengs. You must have ordered just the G4 transmission for the Honda and not the whole kit and this fit your Huasheng perfectly?

    Also, what diameter and length is the shaft that the 11 tooth sprocket attaches to? Does it just use a regular keyway? Couldn't you just get a larger non-freewheeling sprocket on there if that one starts giving you problems? Just curious.
     
    Last edited: Apr 16, 2010
  16. Irish John

    Irish John Guest

    There is only a few mms clearance between the existing sprocket and the engine casing so the drive sprocket can't increase by enough even if you could one that fitted on the shaft. The problem is in the unnecessarily large second pulley wheel that is wrongly sized and makes the already serious size problem of the gear box worse. The rear sprocket could be made smaller but it would then present problems around all the clutter of the hub brake and brake arms etc.
    The new drive sproket is smaller than the old one so that is why I reckon the gain from making the pulley wheel smaller will be diminished and it won't perform as required.
     
  17. I want to get to the bottom of this , I really feckin do .
     
  18. 4G questions answered

    Originally Posted by simonjohnwilmer
    "Recumbentbill's 4G is narrower because it doesnt have the domed clutch cover like the usual HS 4G ....Id like to know how this works , Bills 4G is at least an inch narrower ."
    Look a attached photos "pulley cam body" " haunsheng4G trans' and "Honda 4G trans"
    on the trans photos pay close attention to part# 4 Pulley cam body.

    From abikerider "Hey recumbentbill, did you have to drill new mounting holes on the G4 to fit on the Huasheng? Any special modifications? If not, then why would anyone use the G4 designed for the Huasheng when they could use the thinner Honda one? It sounds like the Huasheng shipped with the G4 as a package has different mounting holes than previous Huashengs. You must have ordered just the G4 transmission for the Honda and not the whole kit and this fit your Huasheng perfectly? "

    ALSO These trans photos show the 2010 upgrades. My trans [Honda] Boes not have the upgrades which is the new style 80t pulley with one way bearing which eliminates the 11t freewheel drive sprocket that Irish John hates

    No holes had to be drilled. No special Mods either. Keep in mind my HS engine is the Honda clone and is quite different to the HS that Irish John is talking about.Yes I ordered just the 4G transmission for the Honda since I already had every thing else.

    There is room on my HS Honda clone for a larger drive sprocket [maybe a 12 tooth solid] that would eliminate the free wheel 11tooth since I am using the HD axle with the freewheel 48t sprocket.

    Hope this clears up some issues:cool2:
     

    Attached Files:

    Last edited by a moderator: Apr 16, 2010
  19. Thanks for the info Bill , yeah I still dont get it , my engine is a HS copy of a Honda , are there two types of Honda Clone ? My engine looks just like yours Bill .
     
  20. Irish John

    Irish John Guest

    That is so informative Recumbentbill. It explains such a lot.
    Thanks for all that.
     
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