gearing ratio problems

[huttronics0001]

My gokart i built only goes 8 miles per hour. it is chain drive to a single speed foreward reverse transmission then chain drive to a solid one inch axle. i figured out the gearing to go 30 mph but i was wondering if the gear changing mechanisms as in a bicycle would be good to change gears to get more speed. or is everything moving too fast for this to work? please help i'm 15 and have been trying to get this to work well for over a year now

 

[devino246]

Bike gears wont work. Im gonna bet you gear box is the problem.

 

[huttronics0001]

the gear box works great mathamatically i have a 1 to 24 ratio, i'd like to get it so i can cahge between 1 to 10, 1 to 9, and 1 to 8. the easiest way to do that is with something outside of my transmission. i know i wouldnt use bike gears but do think something like that would work. however i think the engine may spin at too many rpm to have a transition like that.

 

[r97]

1 to 24 thats lowwwwwwwww gear. if it were me i would get rid of the gear box you have and get a 10t tav30 and a 60t on the axle depending on your tire size. oh and to answer your question a bike derailer sytem cant handle the speed or the torque. if you really like or need the reverse thing you could get somthing like this http://www.mfgsupply.com/m/c/218390A.html with a 20 series tc i think it is. i dont know thats what i would do but its your choice to do anything you want. good luck

 

[Kenny_McCormic]

Change the final drive ratio or the engine-gearbox ratio.

 

[Doc Sprocket]

24:1? Wow! I built my kids' kart at 16:1, and I thought that was sloooowww.
If that ratio is a product of the gearbox, get rid of the gearbox. What is the overall diameter of the rear tires? You'll probably need to be somewhere between 5:1 and 6:1.
How 'bout some pics?

 

[huttronics0001]

well my tires are 20 inches high. which means its very easy to lose torque.but when i did the math i should be able to go 30 mph with a 8 to 1 ratio. i already burnt out a clutch from northern and i'm on too tight of a budget to get a torque converter or a better gear box.

the gear box is a 3 to 1 ratio.

 

[huttronics0001]

this is what i had about 2 weeks ago
i'm going to replace the whole belt thing with chain.

please give me suggestions!

 

[Kenny_McCormic]

Don't replace the belt with chain, just get a smaller pulley for the trans and/or a bigger one on the engine. I am in the middle of building pretty much the same thing, but in trike form.

 

[r97]

i'm not sure if this would work or not but a quick fix might be to just switch the two belt pulleys around. which atleast if it doesn't work it wouldn't cost any thing. if that doesn't work do what kenny said

 

[huttronics0001]

kenny,
i like having a belt but it slips a lot so i lose a lot of speed and torque, what would you recommend to tension it

 

[T-man]

I like those rear tires you have on there, where did you get them??

 

[r97]

i know that you adressed this question to kenny but i think just some more/tighter springs on your belt tensioner would fix the problem.

 

[huttronics0001]

Tman, I got the tires from northerntool but i wouldnt recommend them, they are so big its hard to get them going. with my first drive system with a centrifical clutch i burnt out the clutch in 3 minutes and could barley climb a hill. they were also rather expensive about 60 bucks a piece.

and thanks r97

 

[huttronics0001]

right now i put a bigger pulley on the drive so i think i will so significantly faster. i just cant ride because my front end is having issues so i redid the steering and its only half done. i'll post what happened later tonight or tomorrow.
thanks for all your help everyone

 

[r97]

no problem

 

[huttronics0001]

well, with the new pulley and some new steering i go much faster with much better handling , i haven't clocked my exact speed yet.

however when i start my engine in neutral i cant put it into drive without turning off the engine. the only way to get going is to be rolling forward slowly. that is even when i loosen the the tension on the belt i cant get going unless i'm rolling.

how could i fix this?

pictures coming later

 

[solomon]

are you giving lots of gas when you go from neutral to drive? Might have the ratio to high now.

 

[r97]

can you give us the ratios on the pulleys and on the chain

 

[huttronics0001]

the pulleys are about 4/1 the tranny is 3/1 and the chain is about 5/1