gearing for 500 watt 24v motor

[rd350lc]

I'm making a bit of progress with my kid's trike and have sourced a chinese made 500 watt 24v motor .

What would be the ideal gearing for this for say 30 mins running time ?

The motor comes with a 11 tooth front sprocket and the chain is h25

It is running with Kart rear wheels and tyres and the drive will be from these.


6mm .

Thanks in advance

 

[itsid]

Hi.. well.. with info like that we cannot give you the correct answer I'm afraid!

first, what do you call kart tyres?
(OD is important here which ranges from 10.5 for front racing slicks to about 18 for off road rears)

second the powr of the motor is as important as it's powerband to determine the gearing.. is it a geared motor already (rpms in the 600-900) or ungeared (~3000 rpm)
assuming it IS an EV motor indeed (say a Unite MY 1016 or 1020) based on the fact it comes with a #25 sprocket.

Then again you say it only has a 6mm shaft (which sounds more like a beefy RC motor to me tbh... with much higher rpms)

We can't tell

runtime is a matter of battery juice NOT gearing btw!
the motor doesn't care at which speed it runs at full power as long as it's battery is providing the fuel it'll run.

Sooooo yeah..

Okay.. now.. assuming you run 11" wheels (kart slicks 5" rim std 100cc-125cc senior racing kart)
And the motor runs at around 3k rpm.. you'd want about'ish 7:1 ratio means a 77tooth rear sprocket in your case.
then again, what's the maximum speed you'd want your kid to go on the trike,
what terrain you're dealing with (hilly off road.. flat level road?)
And what type of battery have you got?
What'S the total weight of the trike (trike, motor, batteries and kid)

have you read this thread? it helps determining the motor power needed for certain tasks, it also gives you a rough idea about battery sizes.


'sid

 

[rd350lc]

Thanks very much Sid .

I will report back with the relevant information when the motor gets here in the week .

Appreciate your time .

 

[zogthegreat]

Hi rd350lc,

With electric vehicles, the amount of amps that you draw is directly related to how long your batteries will last. For example, I have a modified Razor E300 scooter. I'm running it with a 36v 1000w motor, with 3 x 12ah batteries, 11/80 gear ratio and a YK43B controller that can throw 150a at the motor almost instantly, (i.e. the little fraker will pop a wheelie from a dead stop).

I spend half of my year in Montreal, QC, which has a lot of hills. I weigh in at , (ahem,), 230 - 235 lbs, so going up a 10% grade near my home, I'm at about 3/4 + throttle, doing about 15 mph. According to my amp meter, going up the hill sucks down 45 - 50 amps. Riding in Montreal, I can go about 3 - 3.5 miles or 4.5 - 5.5 km.

I spend my winters in central Florida, (because, having been born in Los Angeles, CA , I think that -40 REALLY SUCKS!). The roads in Central Florida are mostly flat, with the occasional gentle hill. Down there I can run on an 11/55 ratio. At half throttle, I draw around 25 amps doing 15 mph and I can get around 7 - 10 miles or 13 - 16 km on a charge.

You have to view it like when your driving a car. I you accelerate slowly and gently, you will get better gas mileage than if you hammer it at the light. However, (there's always a however, isn't there?), with electric vehicles, the age of you batteries and how many charge cycles they have gone through, will also affect how many amps can be drawn and how long they will last. This is due to what is known as Peukert effect:

"When a battery is given an AH (Amp Hour) rating, it is always accompanied by the number of hours that rate is taken at. The most often listed rate is 20 hours. ... Peukert's law expresses mathematically that as the rate of discharge increases, the available capacity of that battery decreases."

https://www.batterystuff.com/kb/tools/peukert-s-law-a-nerds-attempt-to-explain-battery-capacity.html

https://en.wikipedia.org/wiki/Peukert's_law

Or in other words, the more you use them, the less good they become!

I hope this helps you. Sorry if it's overly wordy!

zog

 

[ezcome-ezgo]

Zogthesnowbird, well said.

 

[itsid]

Indeed!

And thanks a ton for actually listing some working ratios and the conditions they're applied to.

'sid

 

[alim]

I have a modified Razor E300 scooter. I'm running it with a 36v 1000w motor, with 3 x 12ah batteries, 11/80 gear ratio and a YK43B controller that can throw 150a at the motor almost instantly, (i.e. the little fraker will pop a wheelie from a dead stop).

zog

You got any pics of this thing? How did you manage to cram all that on a Razor scooter? I'm looking at this pedal kart I got off kijiji wondering how the f--- I'm gonna fit a 24v 350w and 2 x 12ah!