New ratio 4G gearbox from Grubee

[Irish John]

Don Grube hasn't ridden a motorised bike further than 50 metres so you mustn't expect much from him. Sorry to tell you but yourr kit is a lemon. It is way too heavy to be a rear mounted kit. It is also the 4G gearbox which is wrongly geared and will cause your HS motor to tear itself apart because it will be revving too high all the time. Don't know what sprocket size he has for the rear wheel but he never gets that right either.
Best option IMO is sell the kit on Ebay and buy a decent rig either one specially made for rear mounting like Eagle Star i think it is or try and get an old Grubee frame mount kit that has the older gearbox. Don't care what anyone says I can tell you the 4G is a lemon and the 4G amended Mark 2 is a lemon as well. I use the old kits because they can be made to work. I've tried a couple of 4G builds and that is how I know they are ****.
Sorry to be the bearer of bad news. Blame Grubee.

 

[occchopperfl]

sigh...

ty for the response.

Im going to put my head down, do as best as I can with what I got, tweak it to get it in ridable condition, and sell it i guess.

Staton or BMP with honda or robin subaru for me... for my 2nd build. I wish it was my first.

 

[occchopperfl]

John,

How about the HS 4 stroke 49cc (142F I think) engine itself?
Use it with a friction drive kit, which would eliminate any 4g drive issues?

TY

 

[Pablo]

Don Grube hasn't ridden a motorised bike further than 50 metres so you mustn't expect much from him.

I think I just stained myself.

 

[Irish John]

sigh...

ty for the response.

Im going to put my head down, do as best as I can with what I got, tweak it to get it in ridable condition, and sell it i guess.

Staton or BMP with honda or robin subaru for me... for my 2nd build. I wish it was my first.

Staton sell good gear and they actually know about their products and have them tested unlike the Chinese kits but having recently built a totally unbuildable rear-engined 31cc HuaSheng supplied by a Company called Powercycle Australia who have had rulings against them for their breaching of the Fair Trades Description Act in Melbourne I have to say that I'm not big on rear-engined chain drives although I could be convinced otherwise. I've serviced a few rear engined belt drives and I really like the belt & pulley wheel on the rear spokes simply because it feels good and it means you don't need a gearbox with its noise and extra weight not to mention power loss.
To build the Powercycle Australia kit I had to fabricate most of the mounting frame and redrill the engine & gearbox casings to take larger bolts. What they were selling was a downright disgrace and they are not alone in the disgrace stakes. Staton is very reputable, offers help by email and he knows his product. I feel you have been dudded with the kit you bought and I feel sad that your government doesn't protect you from traders like these. The whole idea of a 50cc HS with 4G gearbox on a frame above the back wheel is just ridiculous as well as dishonest. I started a web page all about Powercycle Australia telling just how unbuildable their product is with links to the judgements made against them so people realise the sort of shysters they are.

 

[recumbentbill]

4G rack to frame mount

John,

How about the HS 4 stroke 49cc (142F I think) engine itself?
Use it with a friction drive kit, which would eliminate any 4g drive issues?

TY

Sorry to hear about your rear rack4G problems. Since you already have the kit you might try going with the in frame mount[if your bike has the room for it]. you would have to reposition the 4G and get a in frame motor mount from Bicycle-engines.com. I also would go with the manic mechanic sprocket adapter with a 44T rear sprocket.

 

[Irish John]

Sorry to hear about your rear rack4G problems. Since you already have the kit you might try going with the in frame mount[if your bike has the room for it]. you would have to reposition the 4G and get a in frame motor mount from Bicycle-engines.com. I also would go with the manic mechanic sprocket adapter with a 44T rear sprocket.

Or maybe investigate using the existing engine with the EZM frame-mount kit because I think it has to be a better gearbox.

 

[BiMoPed]

Or maybe investigate using the existing engine with the EZM frame-mount kit because I think it has to be a better gearbox.

Hey Bill, didn't you have one of those EZ Q-Matics?
How did you like it?

 

[recumbentbill]

Ezm

Hey Bill, didn't you have one of those EZ Q-Matics?
How did you like it?

Didn't work out. Got a refund

 

[Knuckle_Duster]

I haven't seen the centrifugal clutch on the 4G for Honda but with the old style clutches on previous Grubee gearboxes I found drilling holes as shown in picture helped stop the pinging of the clutch against the clutch bell. Then they made the springs noticeably stronger and it was no longer necessary but it did fix that embarrassing pinging that really sounds bad. A stronger spring would also have had the same effect.

Yeah, I'm familiar with that mod. There's really no place to drill (that I can see) on the clutch that comes with the "Honda" 4G. I've pulled the bushing twice and lubed it with graphite spray, and the motor has been idling pretty well now. Looking forward to having a proper bushing in there. I really like my 4G setup so far, despite the shoddiness I've had to put up with from mfgrs. Pun intended.