Which hub motor for my off road bike?

jackhandy

Esteemed Pedelecer
May 20, 2012
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the Cornish Alps
Morning all,
Time has come to replace the gng chain drive motor on my full-suspension MTB.
I use the bike strictly for single track, forest and trail-centre riding: No road work whatsoever, and the gng is a raucous beast that makes it obvious to anyone within quite an extensive radius that I'm using power. It also tugs the bejasus out of the chain & cogs on the tricky bits.

I had always intended to put a 200rpm bpm in the back wheel, but now I'm tempted by the Xiongda 2-speed motor.

I'd appreciate any input from those that have experience of either, and especially those who have used or tried both.

My thoughts are that the BPM should be bombproof at 200rpm and is quiet; but the Xiongda has that low-speed potential that might warm-up the BPM _ BUT, how noisy is it?
My point of reference is the Ezee rear motor on my trekking bike, which handles the less technical stuff in a most civilised manner.

Just as a subscript to the sanctimonious few that may think I shouldn't be on a trail centre with power...
I now have 2 bouncers, 1 which will remain unpowered: I ride the trails on this until I'm too knackered to get up the ups, then switch to the Cheat bike to continue enjoying myself for the rest of the day.

So far, I get no negative comments; but plenty of interest from shattered dads trying to keep up with their offspring.

Oh, just out of interest, I've been using an Ezee 14ah flat pack battery in a backpack and it works well for me: The Anderson Power poles separate easily when I fall off, or forget to disconnect on dismount
 
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D

Deleted member 4366

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A 201 rpm BPM at 30 amps takes some beating. I ran one at 12S once and 40 amps. It had so much torque that it was nearly unmanageable.

Both my Xiongdas have quietened down now, but in low gear, you do hear the motor because it spins fast. On a steep hill (30% +), you still have to pedal quite hard, and you go right down to your small front cog and biggest rear one. You need a triple chainwheel. The BPM will trounce the Xiongda in a climbing contest, mainly because it can handle more power.

For ultimate hill-climbing, the 48v 201 rpm one from BMSB is a Code 15 or 16. I think that this motor with a S12S controller at 23 A would make an excellent choice if you can get your battery well-forward and you don't mind 15 mph absolute max. You can switch the S12S to current control, which would help tame the torque. The 36v one is normally a code 13 or 12.

All these fancy motors, like Xiongdas and crank-drives, are great if you like to experiment, but the instant sheer grunt of a 500w geared hub-motor with 1200w from the battery is difficult to beat.
 
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drsolly

Pedelecer
Jan 21, 2014
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My XiongDa is almost silent in low gear.
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
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jack, you would be better off ordering the Big Bear kit from Woosh for £499.
http://wooshbikes.co.uk/?hubkits
Not only it's in stock and possibly cheaper than direct import, you get warranty on a well proven 15AH battery too.
 
D

Deleted member 4366

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Back to plan A it is, then...

For peace of mind, I'll go for the bombproof bpm2.

Just one more question before pressing the Buy button:
Does this kit

http://www.bmsbattery.com/ebike-kits/347-bafang-350watts500watts-bpm-motor-e-bike-kit.html

Come with the S_ Lcd3 & S 12s controller?

If not, I'll order the motor/wheel, controller & LCD separately.
Order separately. The controller that comes in that kit is the new version of the KU123, which seems to be not as good as the old one in some respects.

The Woosh Kit has nowhere near the power of the BMSB one. The 500W motor is different inside to take 30A instead of the Woosh 20A.
 
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trex

Esteemed Pedelecer
May 15, 2011
7,703
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at that level, the power is limited by the battery. Unless you build your own battery, where are you going to find a ready made battery with 30A continuous rating? you need warranty when you build a kit!
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
.
I'll be using it at 25a Max. I assume there's no problem setting up the controller for that?

Whoops _ Should have read 22a, same as the Ezee.

Double whoops _ I appear to have edited the original, rather than my reply :mad::(
 
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Deleted member 4366

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I soldered the shunt in my S12S to get 25A because it was quicker. I've got another one somewhere. I might have a go at the settings to see if that works. It seems OK on 25A.
 
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