Go Kart Top Speed calculus

[Quinc]

Thanks Sir. So I am starting with a 60-tooth rear axle sprocket and a 15-tooth motor sprocket. I will try several sprocket ratios to gain an understanding of the impact on acceleration vs. top speed. This is the part of the project that I am looking forward to the most. . Follow me on my journey.... https://m.facebook.com/VenomKarts/?_rdr

You drive this thing yet!?

 

[garolittle]

No Sir. In the final assembly stages now. All theories aside, the one sure way to measure top speed is to charge up the batteries, put on a helmet, take a deep breath and press the vertical petal on the right all the way to the floor. I will do that next month and post the results. I love this project and the great advice from this forum.

 

[Snaker]

I don't have a clue about the other stuff but I picked up on your tire diameter spec which you listed as Maxxis Pink 12". I did a somewhat research on that and it appears to be a relatively normal pneumatic tire. The diameter will vary depending on circumstances: sidewall rating, unmounted and laying on a bench, mounted low air pressure, mounted high pressure, installed and holding up a load. For best accuracy you want it on flat and level ground under test weight. Measure from ground to axle center of drive wheel and multiply by two.

 

[garolittle]

I don't have a clue about the other stuff but I picked up on your tire diameter spec which you listed as Maxxis Pink 12". I did a somewhat research on that and it appears to be a relatively normal pneumatic tire. The diameter will vary depending on circumstances: sidewall rating, unmounted and laying on a bench, mounted low air pressure, mounted high pressure, installed and holding up a load. For best accuracy you want it on flat and level ground under test weight. Measure from ground to axle center of drive wheel and multiply by two.

Very helpful info. Thank you for the information. I will report back the speed tests results soon as possible. Hoping to have everything completed by the end of next month. Thanks again for your comments. VenomKarts.com

 

[garolittle]

So I am going to say 45 mph. Will know for sure next month when I simply turn the key and press the petal on the right. Will post the test results. Thanks for everyone’s input so far.

 

[itsid]

So I am going to say 45 mph. Will know for sure next month when I simply turn the key and press the petal on the right. Will post the test results. Thanks for everyone’s input so far.

hmm.. wheels might be a hair smaller, but that shouldn't cost you 10mph...
I know I was shooting from the hips taking a diagram from that motor with a different (slightly more powerfull) controller.. but 10mph is too much even for that;
considering you need maybe 250 amps of your 600 peak amps
(and that's assuming at top speed the efficiency drops to below 50%)

IDK, maybe I have indeed a mistake in my math somewhere (I'd hate that),
or maybe you push a barn door of air plug with you for some unknown reason.. (I doubt that)

please tell me if and when you found the ten missing speed units
after your tests..

'sid

 

[garolittle]

hmm.. wheels might be a hair smaller, but that shouldn't cost you 10mph.....

please tell me if and when you found the ten missing speed units
after your tests..

'sid

Will do Sid. I am going to lose a few pounds so that should further improve my shot at 55mph. Orion JR. BMS is being installed now and then final wiring a few weeks. I can’t wait to run some tests and posts the results (videos, pictures, etc).