Replacing front hub

[Andy S]

I have an Elife Cruiser with a 250w unbranded front hub motor in a 26" wheel. It's all very reliable and comfortable; I recently had a 70 mile ride without a problem, and I don't even regard myself as a cyclist. Rack battery mount, 2x 10.4Ah batteries managed the mileage easily.
The only thing I don't like is that the motor is a bit weak on hills. It gets up mild hills with some noise, fairly slowly but with little extra effort from the rider, but once you're faced with a long 12% drag you have to work hard pedalling in bottom gear, and with a cadence sensor it's very difficult to restart if you have to stop on the slope. That rather limits rides around the Peak District!
Woosh do a great-looking kit based on the XF07 motor. I don't know the torque figure of my current motor, but I'm fairly sure that the XF07 would be a huge improvement. My first thought is that I don't need any of the kit apart from wheel and motor. Is that just naive ignorance? I'm not keen to get rid of the 2 newish batteries I already own, the LCD display is fine and all the wiring and sensors are sound. But the controller will be for the unbranded motor. Is that a problem?

 

[sjpt]

You may already have seen this: Woosh quotes 42nm torque for the XF07,
https://wooshbikes.co.uk/?hubkits and search down for WHICH MOTOR?
It may be better than your existing motor, but I suspect you will find it won't be a huge improvement.

You may find

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

ebikes.ca

informative. You can play with the details; in particular you may well find your controller is less capable. I've set 17amps which matches the Woosh/Lishui controller, but don't know what the other controller parameters mean.

We've had the Woosh XF07 on our tandem for a bit over 4 years. It isn't powerful enough for that on long steep hills without bottom gear and a lot of help from us, but still gives the extra assist that means we can manage hills we couldn't before. We were warned of the limited power when we bought it but knew but there was nothing else legal and available in 700c wheels at that time. We are still really pleased with it.

I can't comment about whether using just the motor/wheel as a direct replacement will work. I don't think Woosh sell it that way, but I'm sure you can find somebody that does.

 

[Nealh]

What is the elife controller current ?
Changing wheel may not be as simple, how many pins are there on the motor connector ?
Most modern hubs use 8 or 9 pins, 3 or 6 pins are old hat and not common on decent systems.

If you want a hub motor for hills it needs to be a high torque motor 201 rpm - 230 rpm though means it's terminal speed will be 16 or 17mph on level terrain with power, on hills one will see about 8mph unless one is geraint thomas.

 

[Andy S]

Thanks for the advice. It's a 6 pin connector, so the notion falls at the first hurdle! The motor is a mystery, so I can't tell what the spec is.

The only clue is the text "B250W18111806S118" stamped on the side. I don't know what current is passed by the controller.

I'm not bothered about de-restricting the speed, so the 15.5 mph assist limit is fine. 8mph up hills is fine too, but mine won't do that on steeper than a 10% hill without a huge contribution from me. If it can pull a tandem up a steep hill, it's impressive, even if you have to help a lot!

I've had to get off and push up a big hill, I just don't have the leg power to keep going - hence getting an ebike.
Faced with an unexpected steep hill, the bike just won't do it if I haven't got to bottom gear in time. There are 21 gears to get through.

If the XF07 is little better, then there's no point in spending any money. There is a torque sensor kit from Woosh that might improve hill climbing, but I'm not sure whether there's a downside in its cruising ability. It seems a lot of time and money to invest, if the results are disappointing. The more powerful legal hub motors seem to have a slightly better spec but considerably more weight. The 42Nm quoted seems pretty good for a suitably lightweight hub.

 

[Nealh]

The motor is unsensored, the three thin wires/small pins are for a speed sensor in the hub.
One can use a sensored hub but just not use the three extra thin wires at the wire connection to the controller.
The current used should be on the controlelr label, one expects it is 7a continuous /14/15a max.
The other thing to consider is whether the batteries can supply the power for a better motor, one proabably would be better with 17/18a form the controller.

 

[Nealh]

One expects the control system is speed control, the cheaper bikes have some not so good pas sensitivity on the control systems. My Kt systems have good pas activation and only require 1/8 - 1/4 rotation to kick in.

 

[sjpt]

If it can pull a tandem up a steep hill, it's impressive, even if you have to help a lot!

Mostly not that steep (Winchester), not many over 10% and that's just for short distances. They are hills we used to climb without any motor, and neither of us was ever particularly strong or fit even then (just not weak and unfit, and low gears).

 

[Andy S]

Huge thanks to all for the advice. It led me (indirectly) to work out how to increase the power of the bike, and I took it out for a spin this evening to test it out. No hardware changes necessary, no money or time wasted.

 

[sjpt]

Huge thanks to all for the advice. It led me (indirectly) to work out how to increase the power of the bike, and I took it out for a spin this evening to test it out. No hardware changes necessary, no money or time wasted.

It would be good if you could post details of what you did to help others in future.
Enjoy the extra power.

 

[Andy S]

Sorry, yes I should have given details. Nothing amazing. Suggestions about the electrical current levels led me to look at the options on the LED display. Apparently it's a KD58C variant, and I didn't realise that more than 3 power levels can be specified, via a hidden menu option. I set it to 5 instead of 3, and rather than getting the expected finer grading of power, it added two levels above my existing level 3. So 3 is still the former 3, 4 and 5 are higher power. The motor actually runs better on level 5. All good.