Help! geared front hub motor recommendations

topofthehill

Finding my (electric) wheels
May 18, 2019
9
0
Hello

I am looking to buy a 250w front hub motor. Something that I can switch in and out fast when i'm recovering from none electric cycling.

I'm after one that will be happy at say 250w but will go up too 300/400w for short bursts.

Internally geared. Possibly around 10/12 - 1 internal gear ratio for getting up hills.

Something under/around say 2kg in weight (motor only) so I can switch it off on the flat. One where on the flat i can cycle drag free and just use it on the hills.

reasonably efficient and durable.

I'm happy to fit it myself into a wheel or just buy as a wheel motor combo either way.

I'll possibly be paring it with a small battery 36/48v and say a 15 amp controller as recommended.

Which motors are recommended generally/have you had luck with anything similar to the above?
 

Woosh

Trade Member
May 19, 2012
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Southend on Sea
wooshbikes.co.uk
If weight is most important, the Aikema 85SX weighs 1.7kgs but you get about 29NM-30NM with a 15A controller.
I would suggest the XF07, 2.8kg, you get about 35NM.
The main problem is the weight of the battery.
If you want 15A controller, you need to find a 36V 8AH-10AH battery.
 
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Woosh

Trade Member
May 19, 2012
12,130
9,324
Southend on Sea
wooshbikes.co.uk
how do the Aikema and the Mxus compare to the bafang hub motors?
We'll keep in stock the Aikema 85R (cassette version of the 85SX).
The 1.7kg Aikema 85R (rear) (or 85SX front) is good for building lightest pedelecs such as the new Karoo. They are driven by 15A Lishui controllers.
All the other motors are heavier. The general rule is the heavier they are, the higher torque and more current they can take.
XF07 front drive is good for up to 100kg rider, XF08C rear drive good for up to 120kg rider, 36V Bafang SWX02 for up to 120kg, they are driven by 17A Lishui controllers.
Bafang BPM and 48V SWX02 for pulling weight and anything above, the BPM is driven by 20A 36V Lishui controller, the SWX02 by 48V 17A Lishui controller.
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
654
237
We have the XF07 (front hub, 36v, 17 amp controller) Woosh mentions above on a tandem. As he warned us when we bought, a little underpowered for a tandem, but it still really helps and we are still really enjoying the conversion after 1 year, >1000 miles. Shortish leisure rides (up to 25 miles), some hills but nothing extreme (Winchester).
 

topofthehill

Finding my (electric) wheels
May 18, 2019
9
0
I'm not 100% but maybe under powered might be ok as I don't want to damage the forks on my bike being an aluminum racing bike and I'm only about 76kg. bikes about 9.5kg.

I cannot remember the hills in Winchester, I guess the peak district hills might be a little steeper :(
 

topofthehill

Finding my (electric) wheels
May 18, 2019
9
0
If weight is most important, the Aikema 85SX weighs 1.7kgs but you get about 29NM-30NM with a 15A controller.
I would suggest the XF07, 2.8kg, you get about 35NM.
The main problem is the weight of the battery.
If you want 15A controller, you need to find a 36V 8AH-10AH battery.
i noticed somewhere that the 85sx gives about 40nm.
is that just the manufacturers 'perfect world situation'?
or would it produce 40nm with the right controller /suitable controller/more amps?

and can the 85sx be geared in the 201 rpm range?
 

topofthehill

Finding my (electric) wheels
May 18, 2019
9
0

Woosh

Trade Member
May 19, 2012
12,130
9,324
Southend on Sea
wooshbikes.co.uk
i noticed somewhere that the 85sx gives about 40nm.
torque figures are usually quite misleading because they are quoted without context.
Torque depends on these two factors: current and RPM. Without these two numbers, it cannot be verified.
In practice, the only time you need to have the maximum torque is when you climb a steep hill. I always quote realisable torque with my kits and qualify with the word 'about' because there is an imprecision regarding the RPM, assuming that you climb with the maximum output that the controller allows. if your motor stalls, the torque is highest and higher than the figure I give but torque at stalling is not a useful number. If you climb faster than about 8mph with the 85SX then the torque produced is less than maximum.
The 85SX is not as flexible as the XF07. I climbed the hill going up Penhurst Castle with it yesterday and noticed that it is quite sensitive to RPM. Basically, it reaches magnetic saturation quite easily.
 
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sjpt

Esteemed Pedelecer
Jun 8, 2018
654
237
Hills in the Peak District certainly steeper and longer than here; ours are about like the milder parts of the Peaks. There are always questions about aluminium forks with front hubs; I'm sure Woosh would advise. You and your bike probably come in less than half of the weight of us two plus aluminium but not specially light tandem (I'm nearer 90kg)
 

topofthehill

Finding my (electric) wheels
May 18, 2019
9
0
Hills in the Peak District certainly steeper and longer than here; ours are about like the milder parts of the Peaks. There are always questions about aluminium forks with front hubs; I'm sure Woosh would advise. You and your bike probably come in less than half of the weight of us two plus aluminium but not specially light tandem (I'm nearer 90kg)
sounds like rear hub motor might be better.

i was 83kg 5 weeks back but the hills are just as hard currently.