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- Thread starter TripleT
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anderkart
Moderator
Man those are tall tires. Unless you instal a jackshaft and/or torque converter, I'd use and 80 tooth axle sprocket with this 10-tooth clutch: http://www.mfgsupply.com/gomini/gom...entcomet/gominiclutchcometscs400/206170a.html
And get an estimated 24mph top speed at 3600rpm.
Or this heavy duty 10-tooth clutch: http://www.out2win.com/catalog/noram_enf.html would survive with a 70-tooth sprocket. You'd get less acceleration but 4-mph higher speeds.
And get an estimated 24mph top speed at 3600rpm.
Or this heavy duty 10-tooth clutch: http://www.out2win.com/catalog/noram_enf.html would survive with a 70-tooth sprocket. You'd get less acceleration but 4-mph higher speeds.
chris_the_poser
Member
You could use your 60 tooth sprocket if you had a jack shaft gear it correctly and it works great. On my manco dingo I replaced the torque converter with a clutch and sprockets. I have a 10 tooth clutch going to a 17 input sproket and my output is a 9 tooth going to a 54 tooth sprocket with 18" tall tires. That gives me a nice quick acceleration out in our hilly woods, but my motor isn't governed so that helps with speed
chris_the_poser
Member
No not at all I just get more rpms so I can go a little faster than I could with 3600 rpms
I would still gear it to 8:1. You will just have to get a sprocket combination that will do that for you. JS ratios are worked out as follows.
(JS in tooth count/Clutch sprocket tooth count)*(axle sprocket/JS out sprocket tooth count)
(JS in tooth count/Clutch sprocket tooth count)*(axle sprocket/JS out sprocket tooth count)
anderkart
Moderator
TripleT, you could use:
10T clutch
15T J/S input
10T J/S output
54T axle sprocket
To end up with an 8:1 ratio.
With your 18" tires at 3600rpm your estimated top speed would be 23mph.
There's lots of other gearing combinations you could choose that would also result in a 8:1 ratio. Deciding really comes down to what jackshaft and axle sprockets are available to fit at reasonable prices.
Have you found any place that sells axle sprockets to fit your kart?
If not, post a pic of your axle (measure and post your axle diameter) and the bolt-circle hole measurements where the sprocket would bolt on. Measure across from center to center of the bolt holes like this pic:
10T clutch
15T J/S input
10T J/S output
54T axle sprocket
To end up with an 8:1 ratio.
With your 18" tires at 3600rpm your estimated top speed would be 23mph.
There's lots of other gearing combinations you could choose that would also result in a 8:1 ratio. Deciding really comes down to what jackshaft and axle sprockets are available to fit at reasonable prices.
Have you found any place that sells axle sprockets to fit your kart?
If not, post a pic of your axle (measure and post your axle diameter) and the bolt-circle hole measurements where the sprocket would bolt on. Measure across from center to center of the bolt holes like this pic:
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chris_the_poser
Member
Thanks anderkart I know I can change my gear ratio at anytime. I was just trying to show triple t an example of my gear ratio and how any sprocket combination can give you multiple gear ratios. In selecting my ratio I made a chart of possible ratios I could use for which speeds I wanted. Trust me I had the sprocket combos and speeds all wrote out and I choose what would work best for hilly off road use and to date it has worked great
anderkart
Moderator
I do think you'd be best going with an 8:1 ratio if you'll be using that less exspencive 10-T clutch I posted the link to.
If you want, you could skip using a jackshaft and just buy a large 80-tooth sprocket.
2 drawbacks to that are reduced ground clearance and its easier for the chain to fall off huge sprockets like that. An 80-tooth #40/41 sprocket would be 13,25" diameter, that would give you under 2-1/2" of clearance between your sprocket/chain and the ground.
Those 80-tooth #40/41 sprockets are pretty exspencive too, here's the only place I know that sells them: http://www.gokartgalaxy.com/racing_sprockets_for_larger_chain_sizes.htm
If you want, you could skip using a jackshaft and just buy a large 80-tooth sprocket.
2 drawbacks to that are reduced ground clearance and its easier for the chain to fall off huge sprockets like that. An 80-tooth #40/41 sprocket would be 13,25" diameter, that would give you under 2-1/2" of clearance between your sprocket/chain and the ground.
Those 80-tooth #40/41 sprockets are pretty exspencive too, here's the only place I know that sells them: http://www.gokartgalaxy.com/racing_sprockets_for_larger_chain_sizes.htm
Bluethunder3320
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i would go for a comet 30 series. its worth the money. a centrifugal clutch could dissapoint you.
but if you want to go 30+ you are going to need a bigger engine like from a snow mobile or dirt bike
but if you want to go 30+ you are going to need a bigger engine like from a snow mobile or dirt bike
chris_the_poser
Member
Gear for a 6:1 ratio and get a tc
Believe me....30MPH in a kart is plenty fast
, other than a torque converter there's no way?chris_the_poser
Member
Not really. I wish they would just make a 3 or 4 speed tranny for horizontal shaft motors that would just bolt on. I think there would be a good market for them.
A #35 chain should be fine. If you have a larger, heavier kart wit a large engine, then I would recommend a #40 chain
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