[Kartbuilding] Help

[Stephen Burke]

Hi Nat,

I've gotten around 40, 45mph out of some of my karts. You have to be brave 
going that speed on a kart. Also at them speeds, the build quality, 
steering setup etc has to be very good, otherwise things will vibrate etc.

As for karts in general and their speed, I'm not sure. I know indoor karts 
do around 30-40mph. Racing karts can do anywhere up to 100mph.
See: http://en.wikipedia.org/wiki/Kart_racing

Best of luck,
-steve



On Sat, 6 Nov 2010, Nat Snyder wrote:

> Hi steve, how fast do these karts usually go? whats the max speed you have
> hit?
>
> On Tue, Oct 5, 2010 at 8:47 AM, Stephen Burke <stephen at sburke.eu> wrote:
>
>> Hi,
>>
>> You are correct, if you put the large pulley on the engine, and the small
>> pulley on the rear axle, the kart would go faster.
>>
>> However, when you gear up for speed, you loose power and torque.
>> It would be like trying to drive a car in 5th gear. It would stall the
>> engine.
>>
>> Its actually a tough balance to get the sizes of pulleys correct. I
>> typically find that having a rear pulley 4 to 5 times the diameter of the
>> pulley on the engine gives a good speed and good take-off-power.
>>
>> Also, if you do the maths, with RPM of the engine and size of the rear
>> wheel, you would find that there would be large "theoritical" speeds
>> reached.
>>
>> A bicycle is a good example. The person has LOTS of power but low speed.
>> Small engines have LOTS of speed, but relatively low power.
>>
>> You could always try it yourself and see. Get a kart built and try
>> different size pulleys and see what speeds and power you get.
>>
>> Best of luck,
>> -steve
>>
>>
>>
>> On Fri, 1 Oct 2010, Nat Snyder wrote:
>>
>>  Hi, i am using you website for a guide to build a lawn mower go kart
>>> (using
>>> your V-belt Idea). I agree with almost everything you are saying except
>>> why
>>> you should weld a big pulley on the rear axle and a small pulley on the
>>> shaft of the engine. Why would it not be the other way around? It appears
>>> to
>>> me that if you have the smaller pulley on the rear axle you can reach a
>>> higher speed then having the larger pulley welded on the rear axle. Can
>>> you
>>> explain to me why you say to do it your way?
>>>
>>> Thanks
>>> Fellow Go kart builder
>>>
>>>
>