Choosing efficient motor + battery combination
- Thread starter SaladFish
- Start date
700c wheels so, that's around 450 rpm wheel speed. If you could get 10:1 in a single stage for a shaft speed of around 4500 rpm, the Astro 3210 would still be pretty efficient... That would put the peak efficiency torque for it at the right level for cruising at 45-50 kph.CoulombMotorsport said:
SaladFish
10 W
- Joined
- Dec 14, 2015
- Messages
- 71
Miles said:
I had a look at wheel RPM at various speeds.
700c x 23mm Tyre Circumfrence 2.096m
RPM 477.10
Minutes 60
Meter per hour 60,000
30km/h 238.55rpm
40km/h 318.07rpm
50km/h 397.58rpm
55km/h 437.34rpm
60km/h 477.10 rpm
With 15kg bike and 60kg rider and 0.1m CdA.
It may be possible to reach 80km per hour on the fastest lap (1kw+ limited by 3c lithium ion phosphate batteries) but a speed of 55km with 350w.
A 5% gradient would put that as 58km/h and 28km/h.
Needless to say these speeds are likely beyond skills and nerve of a random 45-46kg girl/boy so I might need a light weight motorcycle racer.
The ability to maintain the majority of the top speed of 55km/h and 80km/h through the gokart track's turns while dodging children will be challenging.
50kg vs 60kg body weight is 28km/h vs 30.9km/h so the experience could be worth the weight penalty.
It would be a lot easier and safer if it were electrathon rules lol.
Will the Astro 3210 need gearing for speeds of 28km up to 80km? I am not sure of it's efficient rpm range?
Perhaps two gears.
gear 1 for 350w. 28km/h to 55km/h.
gear 2 for 1kw+. 58km/h to 80km/h.
Also will the Astro 3210 be efficient at only 350w?
I might go for the Turnigy 9235 that was recommended as that will be cheaper and I can allocate the savings towards the expensive fairing.
