Grubee Gen III gearbox

[FlyingSchwinn]

I am tired of the problems that I keep having with my 2 stroke kit and want to get something that is less of a novelty. I really like the look of the Gen III gearbox and that you can run gear oil rather than slathering grease on the dinky gears of the 2 stroke kit. Can one still get a Gen III box without the HS motor that will take a Honda 50 or is the belt drive the only option we have now? From seeing pictures and watching videos on youtube of the Gen III, it seems like a nice well made unit and was very quiet for a gear drive. Thx.

 

[cigron]

I got so tired of all the noise and the work to maintain the stage 111. I took it off
and through it in the trash.If you run it with oil (30ml) it slips to much it`s
useless.If you run it with grease you have to re do it about every 100 miles.
The out put shaft to the drive chain leeks oil and makes A mess. Spend A
little more for the EZM Qmatic.It`s quit.It`s clean. It`s worth the price of sanity.

 

[MotoMagz]

The stageII or III do make a mess.You will also have a problem finding a replacement clutch.I now have the 4G that fits the honda and it is a great set up with the shift kit.I would like to get a American made gearbox but the EZM is to large to work with the shift kit.

 

[Dan]

I also didn't care much for the stage III. I have the 4g but have yet to really try it out. On a brief maiden, shake down run was really impressed with it's torque. A lot to be said for a timing belt. Also, I really like the way it looks. This is Terry's site for pics; http://blowbyumotorizedbicycles.ca/6052.html

Just my 2 cents.

 

[FlyingSchwinn]

I got so tired of all the noise and the work to maintain the stage 111. I took it off
and through it in the trash.If you run it with oil (30ml) it slips to much it`s
useless.If you run it with grease you have to re do it about every 100 miles.
The out put shaft to the drive chain leeks oil and makes A mess. Spend A
little more for the EZM Qmatic.It`s quit.It`s clean. It`s worth the price of sanity.

There was a guy on the site from the link posted who bypassed the clutch inside the gearbox. I was under the impression that the only clutch in the system was the centrifugal clutch that runs off the HX50. If there is a clutch inside the gearbox, how is it bypassed. It seems the reviews on Bike-Engines.com were all good in regards to the Gen III box.

Could someone explain the workings of the Gen III or post pics of it because it seems that the slipping described by cigron could be mitigated by a simple clutch bypass. The leaking from the shaft seal could also be minimized by running a heavy gear oil like a 75w90 or even an 85w140 or one could simply size the seal and find a quality American made or Japanese one to replace the Chinese one.

It seems like the Shing Shang Ding Dong pots and pans down the staircase Honda engine copy doesnt have an integrated clutch and the output shaft mates to the box and utilizes the gearbox clutch...

I would rather have a leaky box than the POS kit I am running now which leaks, slips and sounds like it is going to shoot a gear tooth through my keester when I go over 25 and asphyxiates anyone within 100 feet behind the exhaust pipe. Oh and renders my bike useless as a pedal bike unless the drive chain is removed.

 

[Dan]

The stage III has an "engager" Would engage the final shaft in the box with a sliding action. I always just left mine engaged and let the clutch do the work. That system would work awesome with helical gears. As it is, is kinda loud and sounds like you doing damage to it. I should say, I wanted to try helical but never got around to it. Be a pricey experiment.

Ya know! I just remembered I had left a GB at a buddy's shop to see if he could find any mass produced gears. Been at least a yr and I forgot about it. May try it after all.
Sorry about the rambling.

.

 

[ocscully]

Drawings and photos of Type III Gearbox

Here are some drawings and photos of the inner workings of the Type III Gearbox. The Engager system is not a clutch. Its purpose is to disconnect the motor and primary reduction from the final reduction/drive to the rear wheel, so when you start the motor the bike does not take off and run away from you. It should only be engaged at idle rpm. Engaging this system at rpm above Idle leads to disastrous results.

ocscully

 

[FlyingSchwinn]

I didnt realize that the Honda engines were so expensive. They are almost 300 bucks at small engine warehouse and over 300 anywhere else. I read that the HS copy is identicle at 160 bucks but still expensive for a knockoff. Does the GB Gen III have a bellhousing to hold a centrifugal clutch or is the clutch inside of the gearbox and subjected to contact with the oil and is there any way around this?

 

[cigron]

The motor and gear box are separate.The clutch comes with
the gear box.If you need any parts for the clutch or gear box
your out of luck. Same old holds true for belt on the G4.Give
Duane at thatsdax A call.When I had trouble with my HS and stage111.
he gave me all the help I needed even though he did not have
any thing to sell me.He sent me to A competitor of his
who had what I needed.

 

[FlyingSchwinn]

The motor and gear box are separate.The clutch comes with
the gear box.

Is the clutch iside or outside of the gearbox?

 

[jbcruisin]

You can always get what I run (it's not a Grubee)& there's no oil or grease. You can buy the whole kit or just the drive box.

EZ Motorbike of Lebanon: Welcome to EZ Motorbike of Lebanon

 

[caduceus]

With some fiddling, the Stage III gearbox is relatively bulletproof.

I bored a 1" access hole in the cover, in line with the engine crank shaft, and fabricated a simple screw-on cover so I could easily access the clutch bushing when needed.

I started out using white lithium grease, but that tended to sling away from the gears and degrade quickly in the bushing. So, remembering my agricultural wrenching days I bought a tube of John Deere Cornhead Grease. It's goopy enough to spread evenly over the gear train, but greasy enough so the centrifugal clutch still works well.

Speaking of which, after much fiddling, I set up a hollowed-out clutch key with a cross-drilled hole to match a hole I drilled in the bushing. Now I can grease the bushing by removing the access cover and using a pointed grease needle.

I leave the engager always engaged. It is meant to be engaged/disengaged with the engine off only. Otherwise it makes a real loud and nasty "klunk". Engaging it at speed will probably break the gear box housing.

Clutches are inexpensively available from Bicyclemotors.com. I got a couple of them to tinker with and just yesterday installed heavier springs in one. I have yet to ride it because we got six inches of snow last night. But when things clear off I'll try it out.

I locked the threads on every bolt or screw on the bike with blue Locktite. And make sure both the bolt and the bore threads are clean. Any oil or dirt and any kind of Locktite is worthless.

To clean threads I use Lacquer thinner or Acetone and a clean rag, and Q-tips as needed. Any nuts used must be locknuts. I use the Nylock-type, and whenever possible I use the standard American sizes. Metric lock nuts are expensive at our little-town hardware store.

Get the Honda Motor. It's worth the extra bucks, and as long as it's maintained per the operator's manual - Oil changes every ten hours of operation - it'll last for many years. I have not removed the governor. I figure if the plastic dinky-ass twist-grip throttle ever croaks a hundred miles from home I'll need it.

Just two cents from an old Mechanic.

 

[Dan]

Awesome Cad. The first time I engaged with the engager, really thought it was gonna blow. Could not have got the idle any lower. Couldn't agree more about the Honda. The lil engine that could and keeps going.

I really gotta see Frostbite Falls some day. Tell Rocky and Bullwinkle we said "hey"

 

[caduceus]

Awesome Cad. The first time I engaged with the engager, really thought it was gonna blow. Could not have got the idle any lower. Couldn't agree more about the Honda. The lil engine that could and keeps going.

I really gotta see Frostbite Falls some day. Tell Rocky and Bullwinkle we said "hey"

We're actually 70 miles Northwest of Frostbite (International) Falls, MN. In the area are moose, flying squirrels, Government agents and the occasional Fearless Leader. The last weekend in January there's a ten kilometer race in International Falls called "The Freeze Yer Gizzard Blizzard Run." Twenty years ago when I was considerably more fit I ran in it three years running, never finishing higher than mid pack.

Now that I've got the driveways blown free of snow, I'll spend tomorrow putting Studded Tires on the Mad Martian MB and check out those new clutch springs.

 

[Prof Fate]

This bike? At That Price? Are You kidding?

I recently (today) added a Honda 50cc mounted to a Schwinn Jaguar to the growing collection of stuff cluttering up my garage that I doubt will never see a car inside it. It was built locally by forum member Iceman and it is a great build. Honda with a (I think) Grubee Skyhawk Stage III, poo poo pipe, rear rack with storage bag , upgraded stable kickstand, 12 volt recharging head and tail light, mirrors, speedometer, etc. Pull the rope and go, it needs nothing.

I was poking around on craigslist not even really shopping and when I saw it I had to go see it in person.

$200 !? At that price I couldn’t even try to haggle with him. I literally pulled the cash out of my pocket so fast that I dropped it. lol

With some fiddling, the Stage III gearbox is relatively bulletproof.

I started out using white lithium grease, but that tended to sling away from the gears and degrade quickly in the bushing. So, remembering my agricultural wrenching days I bought a tube of John Deere Cornhead Grease. It's goopy enough to spread evenly over the gear train, but greasy enough so the centrifugal clutch still works well.

I am brand new to this type of clutch system. I read what you said about the Corn Head Grease from John Deere and went to their site and watched their 2 minute infomercial. Looks like the stuff for me. So…do I still need to tear it apart every 100 miles and re-grease it?

PS- I knew that big jar of spare change would come in handy one day.

 

[caduceus]

Re: This bike? At That Price? Are You kidding?

I recently (today) added a Honda 50cc mounted to a Schwinn Jaguar to the growing collection of stuff cluttering up my garage that I doubt will never see a car inside it. It was built locally by forum member Iceman and it is a great build. Honda with a (I think) Grubee Skyhawk Stage III, poo poo pipe, rear rack with storage bag , upgraded stable kickstand, 12 volt recharging head and tail light, mirrors, speedometer, etc. Pull the rope and go, it needs nothing.

I was poking around on craigslist not even really shopping and when I saw it I had to go see it in person.

$200 !? At that price I couldn’t even try to haggle with him. I literally pulled the cash out of my pocket so fast that I dropped it. lol




I am brand new to this type of clutch system. I read what you said about the Corn Head Grease from John Deere and went to their site and watched their 2 minute infomercial. Looks like the stuff for me. So…do I still need to tear it apart every 100 miles and re-grease it?

PS- I knew that big jar of spare change would come in handy one day.

I bored a 1 1/4" hole in the outside gear case, in line with the crankshaft center-line, and installed a small, screw-on, access cover. I can remove the cover, retaining bolt and washer and have the bushing out, cleaned, greased, reinstalled and the motor running in five minutes. It beats pulling the case apart every time I want fresh grease.

 

[Prof Fate]

Re-greaseing Interval?

Caduceus,
Does the re-greasing interval need to be 100 miles regardless of the brand you use? The infomercial at John Deere made their Corn Head Grease made it look like you added it once and forgot about it. This link will take you to the site, then 2nd line down click on "A John Deere Corn Head Grease video is now available. To view the video, please click here."

https://jdparts.deere.com/partsmkt/...alMultiPurpose.htm#_Special-purpose_corn_head

What do you think?

 

[caduceus]

Re: Re-greaseing Interval?

Caduceus,
Does the re-greasing interval need to be 100 miles regardless of the brand you use? The infomercial at John Deere made their Corn Head Grease made it look like you added it once and forgot about it. This link will take you to the site, then 2nd line down click on "A John Deere Corn Head Grease video is now available. To view the video, please click here."

https://jdparts.deere.com/partsmkt/...alMultiPurpose.htm#_Special-purpose_corn_head

What do you think?

Since I'm using a specialized goopy grease on a different purpose machine than for what it's designed I'll leave the John Deere ads alone. I just grease the centrifugal clutch bushing when the clutch gets grabby, which is about every other week, and I can see the Cornhead grease sticks to the gears better than white Lithium grease.

 

[Prof Fate]

Cool thanks. I only rode it far enough to see that it worked. It'll be spring before get any feel for the clutch. Any idea of the speed a 56 tooth produce?

 

[caduceus]

I started with a 44-tooth sprocket, but switched to a 56 after my first 80-mile round trip commute to work. With the 56-tooth the bike handles headwinds and hills better. I regularly cruise at 30 mph with a Honda GHX50. Long hills drop it to 25, even 22. Long hills and headwinds it drops to 20 mph WOT.

But I never have to pedal.