Electric Hub vs RC Outrunner

[benj]

Hello everyone,

I am about to embark on my next project and I was hoping to get some advice on electric hubs compared to RC style outrunner motors.

I see eHubs from 250W all the way up to 4kW. Lovely stuff! But then I also see RC style outrunners which are much smaller and lighter with 2kW and more.

Hows about a discussion on the pro's and con's of each? Thanks all!

For this project, these are the key factors I'd like
- Minimal weight
- Great hill climbing ability
- Doesn't need to be waterproof
- Only needs a roughly 5km range
- Doesn't need a high top speed, perhaps 20km/h

 

[Ypedal]

that discussion has been done to death..... gimme a sec to dig up some links.

 

[Ypedal]

https://www.google.ca/webhp?source=search_app&gws_rd=cr&ei=SGg8UpSFI6Ti2gXJu4GICg#q=endless+sphere+rc+vs+hub

http://endless-sphere.com/forums/viewtopic.php?f=3&t=17650

 

[parajared]

It’s all about windings; the loops of wire wrapped around a cylinder in your motor. You run electricity down these.

RC motor= only a few wraps
hub motor= lots of wraps

Here is the problem, the more times the wires in your motor wrap around the shaft the slower your motor spins, and you want fat wires to handle all the electricity you are pumping down the thing, but you also want lots of wraps because you want your bike to go 20kph not 600kph.

Hub motors sacrifice the extra weight of a few extra wraps to slow the motor down. RC drive owners slap big reductions gears on their bikes and pulley system their 4000rpm motors down to 85rpm or so. You can imagine what kind of noise a chain makes zinging around at 4000 rpm. SCHREEEEREEEREEEREEREEEee… This is totally fine for off-roading your local motorbike track but will make people want to go all UFC on you for riding down their beloved nature trails.

My 2 cents, unless you want to grind it up on some killer rock gardens, or plow your way up the local mountain sandy wash, just go with a hub motor (in the wheel). A high wind motor like 9C 2807 will climb right up the side of anything an urban environment can throw at you.

 

[benj]

Thanks guys. Very helpful stuff.

I'm pretty good with the RC stuff but new to electric hubs. It's interesting to learn!

I would prefer hub drive so I will checkout that 9C.

Cheers!