Advice on first DD rear hub motor

[Bmp264]

Desired max speed on level ground:20-30
Desired max range at what cruising speed:15 mi at around 20-25 mph
Preferred bike wheel size, or wheel size of bike you want to convert: 26 inch
Brake type of motor wheel: Disc
Rider weight: 175 lbs
Terrain: Mostly flat, couple hills.
Budget:300-600

I've been considering buying from Golden motor and getting a smart pie, but is it worth the extra money instead of an ebay 48v 1000w kit? How reliable are the ebay kits?
Thanks for the response

 

[dogman dan]

Reliablity of the cheaper kits will vary. One may run 10,000 miles, another a week before the wheel falls apart. Cheaper the kit, the cheaper the spokes and rim, and the more you have to keep up with them to avoid running them till the spokes break.

The motor itself is more or less bombproof, and the cheap controllers tend to last a year or two.

You'll have about $300 left for the battery,,, so not nearly enough for a good quality bms equipped battery and charger. A more realistic budget will be about $1000. You will need at least 48v 15 ah lithium battery to get your range at the speed you need. Ideally a 48v 20 ah, so you don't drain it completely every trip.

Slowing to 15 mph would make it possible on 10ah.

 

[rborger73]

I'll say my Magic pie III currently has around 17,600 miles on it. Around 3,500 miles the internal controller went out. Gary from Golden motors CA took care of me and got me a replacement controller right away. I've only had to be picked up once, and that was due to a flat on the rear that I couldn't patch The controller died as I was about to leave the house, so it didn't cause me to be stuck. Their newer motors you can get for 600 or less, and that should include display all the wiring and throttle. As well as a ebrake lever and rim. I have been very lucky with mine, but I also am running 12s and never went closer to the max voltage with it. Which is 59 or 60v max I believe. Mostly paved roads, and not a lot of dirt trails or gravel roads. So my experience has been very good. I've also used the Mxus 3t motor and was happy with the performance of that, but it was for a customer and won't be a high mileage vehicle, so can't speak to longevity on that one.

 

[Bmp264]

Thanks for the replies, I've had my eyes on a couple kits from GM.
I can buy the smart pie with external controller for $276 or the EDGE with internal controller at $360.
I'm a bit worried about the quality and design choice of having the controller inside the motor.

Anyway, I was going to pair it with the 52v Mini Cube Battery Panasonic PF 5.8ah plus a torque arm and luna charger for $360.
All combined that's $636 for the smart pie ext and $720 for the EDGE.
The battery should be enough because I'm only riding 12 miles where I'll have access to a charger to charge it to full for the commute back.
300 watt hours battery divided by 20 equals a 15 mile range more or less.
Is there a better way to calculate range? I've been using this article: https://www.electricbike.com/watt-hours/

 

[wesnewell]

My 48V 1000W ebay kit has ~20K miles on it in almost 6 years. Never had a problem with motor. As long as you don't over stress them, they should last almost forever with very little to no maintenance. So no, they're pretty much all the same. 48v 1000w kit and 10ah of 12s rc lipo can all be had for <$400 and give you a top speed of ~28 mph and ~20 miles at 20 mph.

 

[dogman dan]

Yes,, the motor itself is bombproof, even the very cheapest of the DD's.

Personally, I'd opt for external controller, if the pie was chosen. For me,, I live in a darn hot climate.

 

[dogman dan]

Heavy load,, there is a limit to any 500-1000w rated motor if you load it up and climb a mountain. If you do need to do that,, then a 20" wheel will really help with that. A smaller wheel does actually increase torque. ( as felt at the rubber, in other words, you squander less of the existing torque. )

Writing that for others,, he said mostly flat, a few hills. He won't' melt any wires.

 

[Bmp264]

Just in case anyone ever looks at this for advice, I ended up buying a smart pie from Golden Motors because I found out my tire was actually 700c not 26 inch :? . I can post a review here if anyone cares to see it.

 

[tomjasz]

Just in case anyone ever looks at this for advice, I ended up buying a smart pie from Golden Motors because I found out my tire was actually 700c not 26 inch :? . I can post a review here if anyone cares to see it.

Good motor, the only problem is occasionally the controller. Good choice! I built one for a local fellow. I like it.

 

[2old]

Please show us the build and let us know how it turns out.