Whats a good Gear ratio for a 6T front sprocket

N

Nikko

New Member
ive been looking and cant find much,
i have a 49cc 2 stroke engine i ordered off ebay and it has a 6T pinion i think its called. does any one know of a good ratio i can run with that for avg speed and acceleration? btw its going on a 29inch wheel.
 
With that type of engine I have used a ratio of 18 to 1 on a 26" wheel. You can use a jackshaft or get a gearbox with a 3 to 1 reduction.
 
does the gearbox just go where the existing gear is but includes a bigger drive sprocket so i can use a different chain?
 
There are a number of gearboxes that will fit that engine, and yes it will bolt on where the existing pinion gear is now. The 78mm clutch has 4 bolts around it (usually allen head). Remove them and you will see how the engine and clutch mate up. This box should do
ENGINE_KIT_PARTS_PAGE_2
On this page are the sprockets for this box.
ENGINE_KIT_PARTS_PAGE_4

Good Luck
Tom
 
Don't forget that this gearbox will reverse the engine rotation.:-||

If using a shift kit, the engine sprocket should be on the same side as the chainring sprocket.

If using a left-side sprocket, you will need a jackshaft to get power to left side.

For a good gear ratio using one sprocket, it depends what your engine's rpm range is. It also depends how fast you want to go.xct2
 
how does the gearbox change engine rotation? wouldnt it still spin the orignal direction? i dont understand how it changes.
 
Nikko said:
how does the gearbox change engine rotation? wouldnt it still spin the orignal direction? i dont understand how it changes.
Click to expand...
This gearbox does not change engine rotation.
However the chain and sprockets are very low quality.

DSC05252.jpg
 
ok i thot so, and also is there any other way of adding a bigger sprocket to the engine driven sprocket besides this? because i already ordered a 44t rear sprocket and just need a bigger sprocket on the engine so i can add the chain.
 
Nikko said:
.. i already ordered a 44t rear sprocket and just need a bigger sprocket on the engine so i can add the chain.
Click to expand...

hi !

what type/pitch rear 44t sprocket did ya buy ? as you know the Reduction box you linked at ebay is using like Chain size #20 or something which is miniature chain compered to bicycle chain sprockets, those wont work 2gether, wont mix and match 2gether.

edit iirc Pocketbike/minimoto Cagllari chain pitch is 8mm. and bicycle sprocket has 12,6mm pitch if you bought what im speculating that ya did....Unless if you bought 44t pocketbike rear sprocket ?

DAX sells 10t sprocket that fits into the mentioned Reduction box that you linked. it can use 415 moped chain and 1 of the bmx chains.

the Reduction box at ebay that ya linked is in 2 versions at least, with double row chain/double row sprockets and with single row chain/single sprockets. Reduction on the box can be 3:2 (9t & 29t sprockets inside the box)

bye:)
m
 
MotorBicycleRacing said:
This gearbox does not change engine rotation.
However the chain and sprockets are very low quality.

DSC05252.jpg
Click to expand...

As is the clutch bell.......it's a snapper. That gearbox is truly a "get what you pay for" example. $30 shipped is cheap.....so is that gearbox. But it will work, for a while.

dnut
 
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