gearing advice

[Shnitzl]

I have a un known make of minibike that is running 3.50 - 8 wheels rigid frame.

I am either putting a 3 or 5 hp on it

I would like to put a aftermarket tav2 with #35 chain

anyone have advice what sprocket count on the TAV to get and what my rear wheel sprocket count should be?

help would be appreciated.

 

[Bigjake]

How tall are your tires are they skinny like dirt bike tires or wide
Next would be how fast you wanna go or do you want torque or both
It's really a loaded question with many answers

 

[Shnitzl]

How tall are your tires are they skinny like dirt bike tires or wide
Next would be how fast you wanna go or do you want torque or both
It's really a loaded question with many answers

Hi BigJake.
loaded question forsure.

the tire is 15'' and skinny 3''

the minibike is a rigid frame no suspension. I would like to try it on some of the trails at the back of the farm.
my small wheel bike with suspension bottom out on rocks.

id rather it be on the torque side then speed.

my other bike is about 18.6mph and is comfortable. if I can get something like this it would work since its a rigid frame.

id take any suggestion over my own as I am new to the torque converter.

 

[chrisr]

This may help.

https://electricscooterparts.com/motor-jackshaft-wheel-gear-ratio.html

 

[Shnitzl]

I like that conversion as it has the jackshaft, however I am not sure what to take into account with the CVT

looks like a good starting point would be 12 tooth off the CVT for 35 chain. and 70 tooth on the axle for the 15" tire.

this is similar to my small wheel, I am 14 tooth on the centrifugal clutch to 70 tooth on the axle and performs well. with 5hp tecumseh stock.

 

[chrisr]

70/12=5.83 or 70/14=5. The 5:1 gives you more top end whereas the 5.83:1 would be better for climbing hills. The CVT normally just replaces the centrifugal clutch and either ratio should be ok for your small tire size.

 

[Shnitzl]

awesome I will give the 70 / 12 a try. I can always bump the rear drive sprocket tooth count around
the CVT seems to only be offered in a 12 where I am getting it. should be fun!

 

[Bigjake]

You can find a 10t for the front to it's not to bad to change once you know how they go together
I have a Coleman ct200u ex with a tav and its geared 6/1 with 19 inch tall tires 10 front 60 rear and it will climb more than I want to and still run 30 to 35 never tested top speed but faster than I wanna hit a tree
So your 12/70 you should be happy with

 

[Shnitzl]

perfect that sounds good to me!

seems like if I thought of the TAV like a centrifugal clutch it isn't bad. I think the variable ratio was confusing me on what to choose.

a side question,

Jackshaft because I will eventually toy with them, what are the benefits? seems like more fine adjustment of ratio but anything to take into consideration?

 

[gasgas300]

I have a un known make of minibike that is running 3.50 - 8 wheels rigid frame.

I am either putting a 3 or 5 hp on it

I would like to put a aftermarket tav2 with #35 chain

anyone have advice what sprocket count on the TAV to get and what my rear wheel sprocket count should be?

help would be appreciated.

I DONT TRUST #35 chain be better to go with #40 especially sense almost all chain is cheap china crap now days in that size

 

[Shnitzl]

interesting! I haven't had a problem yet with the 35 but the last chain I ran was quality.
I just put on a cheap chain and it is holding well on the centrifugal but only have maybe hour run on it. so to early to tell.

problem local is I don't have a good selection of affordable 40 sprockets. they only go up to 60 tooth count and odd in-between sizes.
I will take this into consideration, I might have found someone that puts both 40 and 35 sprocket in the kit not sure if I read that right.
if it is I will try it out.

 

[Bigjake]

Jackshaft because I will eventually toy with them, what are the benefits?

The only ones I played with is the coleman it's good for gear reduction but once you put a torque converter on theirs no looking back does it all for you and keeps your top speed
And the 35 chain i always order enuff to make 2 and keep a spare but yea if you can upgrade I would if its gonna be put through hell

 

[gasgas300]

#35 chain made 30yrs in America ago was decent stuff now days almost all #35 is very cheap china crap!

 

[minibikin']

Remember that a TAV multiplies your static gear ratio by 2.7:1 in low gear. Final or overdrive ratio is .9....

 

[Shnitzl]

so even lower, low. so yes then no need for jack shafts.

the kit I ordered says it comes with both 35 and 40 sprocket so I will use the 40.
and the bike originally was a 40 rear tire sprocket so I can use that one and see how I like the ratio!

win win.

 

[SAS289]

so even lower, low. so yes then no need for jack shafts.

the kit I ordered says it comes with both 35 and 40 sprocket so I will use the 40.
and the bike originally was a 40 rear tire sprocket so I can use that one and see how I like the ratio!

win win.

How many teeth on the rear sprocket?

 

[Shnitzl]

How many teeth on the rear sprocket?

I went and counted them and its 68 so id say we are good to go?
I will test with it and likely buy a new one as its worn. if you think I should stay with 70 thats fine

 

[SAS289]

So you are going to try the 10 tooth in the kit with the 68? That should be ok to test with if you will eventually get a 70 tooth. It will give you the idea if you want to stay around that gearing or change further in one direction or the other.

 

[Shnitzl]

I forgot it would be a ten tooth with the 40 chain size.
it should have lots more torque then, might be good as I toyed with the idea of making a side car to carry parts.
I sometimes part out a odd tractor or two and keep them at the back of the property. something to carry tools and parts could be fun.

but I have so many projects already!

I will try the setup and decide like you said. should be safest way to do it.