Electric Kart Gear Ratio Help?

[mictuc]

Hi, I'm in the process of building an electric kart for my senior project in high school. I have a 500W 36V motor which is rated for 2750 RPM, which is coupled with an 11 tooth sprocket. All told, the kart when finished will weigh about 100-120 lb, add myself at 200 lb, and I have 10 inch wheels. I'd like to get it going above 15 mph, perhaps closer to 20. (The faster the better ) My question really is if I should get a 47 tooth sprocket or a 55 tooth sprocket for the drive wheel? I calculated the theoretical top speed of each to be 16.4 and 19.1 mph respectively. However, I'm more concerned about torque this would put on the engine, and making sure I can get going. I've also considered trading the motor up to a 750 or 1000W so to increase acceleration a little more. Any thoughts?

 

[itsid]

in fact yes
read this thread,
and you'll get an idea what the 500 W motor can do for you
acceleration and top speed wise.

300+ lbs is about 136+ kg.. let's just assume 150 kg and you can even see my examples there matches your kart well enough.

once you know what your top speed should look like,
you can find out your gear ratio rather easily (as you did)

personally I think acceleration is much more interesting than a higher top speed
(what's that worth when you don't find a parking lot big enough to reach it? )
So I think the 55 T sprocket would be the better idea for your kart...
and twice the power is twice the power (for half the time )

'sid

 

[landuse]

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