Top Speed of Belt Drive Chinese 4 Strokes

Sidewinder Jerry

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You must not know what a shift kit chain guard looks like. Guess you can't see the chain guard with the snake decal or the guard over the tension sprockets??? Only the gas tank is see through. I don't wear bell bottom paints either. Those went out of style in the 70's.
 

JerryAssburger

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Apr 20, 2017
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You must not know what a shift kit chain guard looks like. Guess you can't see the chain guard with the snake decal or the guard over the tension sprockets??? Only the gas tank is see through. I don't wear bell bottom paints either. Those went out of style in the 70's.
Oh CRAP! (Quickly emptying my dresser of all the bell-bottom pants.)
 

Mike St

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Jun 16, 2008
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Jerry, I calculate your theoretical top speed with a 32 T rear sprocket at 33.7 mph.
The problem is at this gearing, your torque will be too low for the power you
have. Definitely, I would boost the power of the motor. The lowest on this
setup should really be no lower than 36T, 41t better. If the engine is
governed, the rpms will be limited. You'd have to purchase the Grubee
ungoverned HS 144 to go higher but it wouldn't fit the belt drive, so
there is no real option to go faster. One more point, the Project Farm
guy is using a 3:1 gearbox, which would give him extremely poor
torque. You're using a 5:1 belt drive.
 

Sidewinder Jerry

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Your best option for top speed for a given terrain is a shift kit build. I suggest doing a 1x4 setup instead of a 1x6,7,8.

With the 1x4 there'll be less cross chaining. Still you could also use a 3 or 5 speed IGH. Get a tachometer/hour counter as well.

I have a thread on how to make a 4 speed freewheel (34,28,22,16) that's right the spacing between the cogs is 666 😈.
 
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Will'smotobikes19

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I'm posting this because some on the net are claiming 35mph as top speed
on these 4-stroke kits equipped with belt drives.
Assuming the belt drives are 5:1, here's the calculated top speed on a 26 inch bike:
44T rear sprocket, 10T drive sprocket = 25 mph
41 rear sprocket, 10T drive sprocket = 26 mph
36T rear, 10T drive = 30 mph

I see a friction drive as a better option, powered by a GX50 Honda.
With a staton drive equipped with a 1.5 inch roller, top speed is 31mph.
All the power is applied to the wheel with no power losses caused by
transmissions or vibrating chains.
For more speed, and noise, a user can select a 2 stroke Zenoah G43L capable of 12,000 rpm.
At 10,500 rpm a friction drive Zenoah with a 1.34 inch roller, top speed is 41mph.
https://www.davesmotors.com/zenoah-g430rc-g43l-42cc-complete-engine-ga41046

The fricton drive is extremely attractive for motorizing a bicycle, and capable of mounting
to any bike.
The GX50 is 9.1 lbs according to staton inc. On to something there uses a more common size clutch not that 78mm shoes diameter that huasheng uses. I would still prefer some type of chain drive system with the engine mounted closer to the wheel hub. The staton chaindrive has too much resistance and too much reduction. A 5:1 gearbox mounted on some sort of bracket filled with gear oil is all you need not a giant CNC box with 3 gears inside. Although I've never tried a staton chain drive it still says the top speed figures which are low.
 

Sidewinder Jerry

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Mar 14, 2011
Messages
2,256
I'm posting this because some on the net are claiming 35mph as top speed
on these 4-stroke kits equipped with belt drives.
Assuming the belt drives are 5:1, here's the calculated top speed on a 26 inch bike:
44T rear sprocket, 10T drive sprocket = 25 mph
41 rear sprocket, 10T drive sprocket = 26 mph
36T rear, 10T drive = 30 mph

I see a friction drive as a better option, powered by a GX50 Honda.
With a staton drive equipped with a 1.5 inch roller, top speed is 31mph.
All the power is applied to the wheel with no power losses caused by
transmissions or vibrating chains.
For more speed, and noise, a user can select a 2 stroke Zenoah G43L capable of 12,000 rpm.
At 10,500 rpm a friction drive Zenoah with a 1.34 inch roller, top speed is 41mph.
https://www.davesmotors.com/zenoah-g430rc-g43l-42cc-complete-engine-ga41046

The fricton drive is extremely attractive for motorizing a bicycle, and capable of mounting
to any bike.
Most bicycle computers round off to the nearest 1/10 of a mile; I'll do the same. Here's the most accurate formula for calculating speed in mph.

RPM ÷ Total Reduction × Wheel Diameter × ⚻ ÷ 1056 = MPH

6800÷(5×44÷10)×26×⚻÷1056=23.7 mph

6800÷(5×41÷10)×26×⚻÷1056=25.4 mph

6800÷(5×36÷10)×26×⚻÷1056=29 mph

6800÷(5×32÷10)×26×⚻÷1056=32.6 mph
 

Sidewinder Jerry

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Messages
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The GX50 is 9.1 lbs according to staton inc. On to something there uses a more common size clutch not that 78mm shoes diameter that huasheng uses. I would still prefer some type of chain drive system with the engine mounted closer to the wheel hub. The staton chaindrive has too much resistance and too much reduction. A 5:1 gearbox mounted on some sort of bracket filled with gear oil is all you need not a giant CNC box with 3 gears inside. Although I've never tried a staton chain drive it still says the top speed figures which are low.

Staton has two different size gearboxes 18:75:1 and 16.04:1. On 26" wheels with a 1:1 drive ratio and at 7000 rpm where max hp is for the Honda 50.

7000÷18.75×26×⚻÷1056=28.6 mph

7000÷16.04×26×⚻÷1056=33.5 mph
 

Sidewinder Jerry

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On my current build the reduction range is 66.79:1 to 16.25:1; I use a Staton system. I weigh 230 lbs the bike weigh close to 100 lbs when tools are in the ammo box. The engine is a RS 35. On level ground I can do around 29 mph. I can go up any hill at least 8 mph. Here in Tennessee 30%+ grade hills are common. The SI system has held up for more than 11 years; with no major repairs done to it.
 

Mike St

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Jun 16, 2008
Messages
499
Your installation is way to complicated and expensive. Long ago, I accomplished the
same result with my RS 35 using a simple $29 5:1 scooter gearbox with a 17T sprocket
driving a 54t sprocket for a 15.88 ratio. It's a double-sided right drive. The setup
drives the rear wheel so it's safe. I designed the motor mount with simple aluminum
and steel angle iron. It has always been very reliable without the use of expensive
staton parts and fun to ride. I'm planning right now beef up my motor mount for the
gx50.
 
Last edited:

Will'smotobikes19

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Apr 9, 2018
Messages
2,152
1619472002305.png

Is it this one? I have one taken apart that was on a 2 stroke mini chopper
 
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