4 stroke belt drive and grubee push me tractor. Honda GXH50

jlebh1

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Hi I was looking at the china-gas website (grubee) and they are bringing out a 4 stroke belt drive (still chain drive to the rear wheel though) and a push me tractor (pusher trailer similar to ones seen on here.)

Here is the link - http://www.grubeeinc.com/USA/To See Whats Coming.htm

The only bit that is belt drive is the gearbox on the frame mount the actual drive from the gearbox to the wheel is chain and the gearbox is belt drive insted of the gears like the old one
 

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I dont know how much i would trust the quality of the belt driven one? How is it belt driven if its still a chain that connect to the bak wheel? Just the gearbox that is belt
 
Same way a primary drive on a motorcycle can be belt with a chain drive to the wheel. It's proven technology.
 
I'm impressed, and I can't wait to see it!

It's hard to tell their exact size from the picture, but it looks like they chose some fairly substantial components for their belt drive. Hopefully they won't cheap out when it comes to the production version.

Don't worry about timing belt type drives being up capable of doing the job. They were a custom item used for the primary drive on Harleys for years. Finally seeing this as a significant trend, the HD factory sent a bike over to Gates (the major US belt maker) for them to engineer a belt primary drive for them. The bike came back to them with BOTH primary and secondary chain drives replaced with Gates belts and pulleys, which Harley still uses to this day.

The big advantage of a timing belt type drive is that it is quiet and light, requires no lubrication, and has far less stretch (thus less needed ajustment) than chains do. As long as the components are sized appropriately for the task, there really is no downside to them!
 
A frame mounted four stroke without the troublesome gearbox.....seems what some have wanted. Centrifugal clutch would freewheel and the drive sprocket mounted on a disc brake hub to eliminate the fiber thing.

Now if they just make the drive assembly available separately.........
 
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belt drive cvt transmission like on snow machines are available. i got one for 30 bucks.

Yeah, but have you got it so it works? The Grubee drive looks w i d e to me? And I know that chinese cvt is wide also. At some point we need to start thinking narrower, unless you never care about pedaling at all or for more than a few minutes at a time. The current 4 strokes are designed for small machinery applications where width is not an issue. Look how much narrower the Whizzer Motors are in comparison that were designed from the ground up to be adapted to a bicycle.

From Sheldon Brown,

"Tread ("Q Factor")

The tread, or "Q factor" of a crank set is the horizontal width of the cranks, measured from where the pedals screw in. The wider the tread, the farther apart your feet will be. It is generally considered a good idea to keep the tread fairly narrow. There are three main reasons for this:

The hip joint is optimized for walking, and in normal walking the footsteps are pretty much in line, with little or no "tread."

For standing pedaling, the farther out the pedals are from the centerline, the harder you have to pull on the handlbar to counterbalance the tendency of the pedaling force to tip the bike sideways.

The wider the tread, the higher the bottom bracket needs to be to prevent clipping a pedal while pedaling through a turn.

Older bikes were generally designed to keep tread to a minimum(think Whizzer here), but starting in the late 1970s there has been a trend to wider tread, for a variety of reasons:

The popularity of triple-chainwheel cranksets has moved the right side outward.

Front derailers designed for triple-chainwheels have a more 3-dimensional shape to the derailleur cage, which requires more clearance between the large chainring and the right crank.

Mountain bikes have wider-spaced chainstays for tire clearance, which requires moving the chainwheels outward so they won't hit the chainstays.
Newer bikes with more sprockets in back move the chainline outboard."
 
It has a tractor tread type tire, which may ride noisy and wear fast compared to a zig-zag type tread. A change of tire would make more miles.

Also the engine is kinda high for a 1-wheel design, but it looks nice for a pusher. I wonder how fast?
 
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