Sunlova anyone?

[JohnD]

Same here

I find the same - I have the same 8Fun motor but fitted to a 700c wheel and I notice very little drag at all.

 

[flecc]

That`s by firing the motor up and not by hand

Understood now Dave, but that reducing spin is still different from maintaining a constant speed by pedalling.

I could and frequently did ride my Panasonic motored Lafree switched off for up to three miles when leaving home, depending on flatness of route. I wouldn't dream of trying that on any of the hub motored bikes I've ridden/owned, a mile of flat is as much as I can stand and I prefer to run with some power all the time.
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[GeoffM]

Of course many e-bikes have a rear hub motor which aren't affected by the above, and I prefer them in the rear hub.
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I've often wondered why some prefer the motor in the front wheel. Surely the force of the motor will put a great strain on the headset if "pulling" the bike and rider?
I'm much happier with the mass being "pushed" via a rear wheel hub motor - They've always been "push-bikes" right? (even with electric power!)

 

[flecc]

I've often wondered why some prefer the motor in the front wheel. Surely the force of the motor will put a great strain on the headset if "pulling" the bike and rider?

Rear motors can't use a cassette gear system and have to use the weaker multi-sprocket freewheels which have much less choice of sprockets. The front hub motor leaves one with full rear hub options for deraileur or hub gears. Therefore they are simpler, more adaptable, and the power isn't very great so the strain isn't much of an issue.

There's one more advantage with a front motor too, two wheel drive which is best on loose or slippery surfaces.
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[GeordieLad]

Sunlova electric folding bike

I recently purchased an electric bike (E-8F20F01BL) from Sunlova and, so far am very pleased and I am considering buying another for my wife. The general build quality is good (with the exception of the flimsey front light!) but it seems significantly heavier than my Dahon D7. We caravan a lot and it is very useful to be able to fold the bike to carry in the boot of my Subaru Tribeca. My friend (who owns 6, yes 6, electric bikes!) tried it while we were in Coniston for a weekend caravavving and loved it. It flies up hills and if it does start to struggle a bit you just switch on the throttle and open it up for a boost! The battery life seems to be very good. We (me, the wife and all our friends) used it constantly over the weekend at Coniston without a re-charge! The User manual is adequate but typical Chinese translation!

However there are a few modifications I would like to make and have recommended to Sunlova.

1. I find, when switched on, the assist kicks in a bit too soon and too hard. As I would only like to use the assist to help me up hills (I am 62 and am recovering from a Stroke and so need some exercise!) I would like to fit an ON/OFF switch on the handlebar so I don’t have to stop each time I want to turn the battery on and off (the switch is located on the back of the battery which means reaching down, behind, to the left - not recommended whilst riding!).
2. I find the gearing too low for day to day use and would like to fit a different set of gears similar to my Dahon D7 folding bike (Shimano Nexus 7 speed, 11 – 30t cassette).
3. I need to extend the handlebars forward by approx. 1-2”.

I can buy an ON/OFF switch to fit onto the handlebar but need some advice on whether a standard, universal switch is safe to work on a 36V/250W battery (I have emailed both Sunkova and the switch manufacturer but no reply yet).
I can probably get the gearing upgraded at Halfords but at what cost?.
I can probably by a Stem/Quill to replace the one Sunlova supplied.

I feel that once these modifications have been made and considering a Wisper would cost me £1,200 and a Dahon would cost £1,500, the Sunlova will be great value for money.

 

[donnoirf]

I had the sunlova kit also & I find the same, that the pedal asisst kicks in very early & is very sensitives.

The sunlova instructions seem to indicate that the pedal assist should work only when you press the red button in, However a post on here yesturday seems indicate that when pressed in this button gives you " high power pedal assist" but when not pressed in it gives you a lower power of assistance.

I am yet to test out this theory as we have too much ice in the midlands to even walk let alone cycle.

 

[Deleted member 4366]

To make an on/off switch is very easy: Any latching push-to-make switch that you can mount near a hand grip will do. You only have to scrape of the insulation from one of the wires to a brake switch and splice the push-to-make switch in parallel. Then re-insulate. When setthe new switch "on", it has the same effect as operating a brake switch and cuts the motor, so can be used as an on/off switch that cuts both the throttle and pedal assist. I made this modification on my Sunlova, so I know it works perfectly. There was a light switch already mounted on the handlebar so I used it, and put a toggle switch directly on the light.
Regarding the red button: on some Sunlova bikes/kits the red button activates the throttle, which will give a noticeable boost when you hold it open whilst pedalling. As far as I can determine, the throttle takes precedence, so that if you hold a quarter throttle, you don't get so much power when pedalling, so you have to be careful not to open it a bit while pedalling because you get nearly no power.
I see there are a few posts about drag from a Bafang front hub motor. I can't understand this because I get absolutely none and nor does my neighbour, who has the black painted type Bafang motor. Both bikes will freewheel easily, while at the same time I am pedalling my non-electric mountain bike quite hard! Anyway, I thought that there is a freewheel inside the motor, so how could anybody experience any noticeable drag? You will of course feel drag when turning the wheel backwards because the motor is then turning and acting as a generator.

 

[NRG]

There is some drag and it's noticeable, spin the wheel up off the ground time how long it takes to stop. Now do the same on a normal wheel with OK bearings and note the difference

 

[Deleted member 4366]

NRG and Flecc, I've just done this test on my Sunlova Bafang front hub motor bike by turning my it upside down and spinning the wheels by hand using the same speedometer fitted to the back and front wheels:
Time for front wheel to stop from 10mph average of three times all within a couple of seconds for each test:
Front wheel: 22 seconds
Back wheel: 24 seconds
So, it does seem that there is a tiny difference, but it would not be noticeable on the road. The motor has a freewheel inside it so the drag is in the same range as a normal backwheel freewheel. When I ride my bike with the electrics switched off it rides just like any non-electric bike (if not better) and is miles better than my non-electric Claud Butler mountain bike (before I converted it to electric using the same wheels as my Sunlova).

 

[flecc]

NRG and Flecc, I've just done this test on my Sunlova Bafang front hub motor bike by turning my it upside down and spinning the wheels by hand using the same speedometer fitted to the back and front wheels:
Time for front wheel to stop from 10mph average of three times all within a couple of seconds for each test:
Front wheel: 22 seconds
Back wheel: 24 seconds

Thanks d8veh, there's no doubt that there are very big differences in this for varying models, bikes and states. Some are reported to ride easily without power as yours does, but many are a misery to ride without power, even when tyres are changed to small section free rolling types. I've never been able to pin down exactly why this is since the motor models are so similar.

As I regularly point out however, spinning by hand which doesn't reach high speeds and then checking run-down time isn't a true test of this ability. A bike that rolls quite freely at lower speeds like 5 to 10 mph can rapidly become a pain to pedal as speed rises beyond, and maintaining a steady speed takes sustained effort where none is put in when only kinetic energy is used during run-down.

For me the ability to happily ride unpowered with a Panasonic unit bike for miles but finding even a mile on the same flat route with the average switched off front hub SB leaves me exhausted is proof enough. The difference is too stark to ignore when there is nothing else to account for it. I wish it wasn't so.
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[Deleted member 4366]

I understand what you are saying, but there's a freewheel in the hub meaning that the motor is stationary relative to the wheel no matter what speed you spin it, so there shouldn't be any reason for front wheel drag unless the clutch is stuck - like what happened to a guy on the ES forum, in which case the motor is acting as a generator and will cause a lot of drag.

 

[Deleted member 4366]

Sorry, I meant the rotor of the motor is stationary relative to the stator during free-wheeling. The complete motor is stationary while the wheel moves around it seperated by the clutch

 

[flecc]

I agree, which is why it's puzzling. And of course I'm not alone in complaining of this, many other members expressing themselves strongly about it and some remarking on how much better they found the Tongxin Nano roller drive motor and the later Panasonic systems,

Even the earlier Panasonic unit in the Lafree with which the chain had to drive a pair of internal gears before the freewheel disconnection was far better, and I used to ride mine the first three miles without power at up to 18/19 mph in the one flat direction I have. I couldn't attempt anything like that on some front motored SB bikes, one I could only manage at a maximum of 13 mph for very limited periods.

Converting the bike parts for maximum efficiency and with the SB motor set up for best free spinning on two bikes has enabled me to reach much higher speeds unpowered, but there's no way I can maintain those in the way I can on other e-bike types in their standard trim.
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[NRG]

The planet gears still rotate with the wheel on the Bafang and similar motors in freewheel as they are permanently engaged with the motor outer housing. I see if I can check my Alien again but I seem to recall 75 seconds to slow from 17mph and the rear freewheel taking over 3 mins.