Is the 8FUN Kit still the one to beat?

[Caph]

Thinking about ditching the Alien Ocean GS2 and swapping it for a mid-range MTB (or high end MTB in Ebike terms). As practical as it is for a commuter, the terrible ride experience has exhausted my patience, all the more so since my other bike is full suspension with RockShox forks and is a joy to ride. Is the 8FUN kit still the one to beat or has anything else appeared in the last couple of years since I last looked?

I'm talking 36V, 8-10AH, reasonably quiet front wheel drive, good freewheel (i.e. non direct dirve), with at least 30 miles on full throttle with no discernable voltage sag for around £400 i.e. decent battery, decent controller, and decent motor. I'm not looking for anything special, just a decent all-rounder.

I'm thinking about this as a donor with full length mudguards and rear rack. This bike is probably the best illustration of why you will never see anything like this quality ever offered on an ebike at a sane price. The sheer buying power of Decathlon dwarfs what an ebike manufacturer can ever achieve meaning the forks and brakes alone almost make up the full price of the bike.

As an aside, I'm assuming that hollow crank is a minor workaround for the square tapered BB sensor? It's just magnets and a sensor at the end of the day right? Glueing them to the small chain ring would work just as well for the sensor?

 

[103Alex1]

I'm thinking about this as a donor with full length mudguards and rear rack.

Nice spec - really good value. Cost me more than that for a 6 year old Trek !

.. and what a refreshing change to see a MTB come with clipless pedals as standard on supply. It's usually the 1st thing I have to factor in going out and buying.

 

[KirstinS]

I have 8fun kit and it will not deliver on all your requests I'm afraid. The panasonic batteries they use do suffer from a significant sag - the internal resistance is quite high. You wont get 30 miles on throttle only without sag/speed drop. You will get 30 miles with pedalling but thats at upper end of useful range (i.e) before you are only doing 10mph

However, what you do get is good aftersales service. Seems i had far worse luck than most but they changed everything but the motor at least once, for free, under warranty. The battery twice !

if you are not fussed about the aftersale service you may be better off ordering a kit from BMS battery with a big ole battery (15 or 20ah)

a q100 kit plus 36V20Ah Li-Ion NiCoMn battery 546 USD (360GBP) delivered to your door

i'm belive the q100 is also more freewheeling thatn the bafang/8fun motors

cheers

 

[Deleted member 4366]

If you're happy with the power of your Alien, the 8Fun kit should be OK; however, it won't do 30 miles at full throttle, and you'll struggle to find a kit that'll do that. The Ezee kit is the only one that comes to mind, but they're a lot more expensive. They're nice and powerful and have lots of battery options. I think that the 8Fun kit is a nice starter kit, but if you want to convert a nice bike, there's better options, but always more expensive. I prefer one with nice LCD display with more PAS levels.

On a decent bike with hydraulic brakes, brake cut-off switches will always be a problem. The easiest option is to change the back caliper to a cable one, otherwise you need to add an in-line hydraulic switch, which costs about £40, and involves bleeding your system. If you have cable brakes, you want the "hidden wire" brake sensors rather than the crappy e-brakes that come with most budget kits.

The PAS sensor is easy with hollowtech cranks. You remove the sensor from its bracket and put it on the other side of the bracket so that it reaches forwards instead of backwards, then drill out the hole in the magnet disc to 25mm. You can remove one of the spacers behind the bearing holders in your BB to compensate for the thickness of the magnet disc.

For a ready-made kit, the Oxydrive isn't bad. It has a bit more power and speed than the 8Fun kit, looks nice in black, and has a nice LCD display, but twice the price of an 8Fun kit.

There's loads of new nice motors now, so if you want to make something tailored to your exact requirements, you can pick and mix components from Aliexpress, but then you get no warranty, and the stuff that comes is sometimes slightly different to what you ordered.

 

[JuicyBike]

Hi Caph
I hope you've had a look at our kits, using the same components as our built bike range. There's some member experience here and others on the forum have them installed.
All our bikes use the reliable SB motors.

 

[Caph]

Thanks for all the replies.

Kirstin, I think you may have a problem with your kit. My 8Fun kit with 9Ah rack battery gives me over 30 miles with very little drop in speed and that's after a couple of years of use. I always use full throttle but pedal all the time too. Funny you should mention BMS, I've just ordered a battery from them. It almost sounds like the 8Fun is using an NiCoMn battery now, does anyone know if that is the case? That may be a deal breaker for me due to the substantial sag I've heard about with this battery.

D8ve great info as usual, thanks. I'm reassured about the bb sensor with hollow crank now. I was just going to glue a reed switch and magnet to the brake levers, is it not as easy as that? My bseen lights used this setup for the brake light and it worked well. Is the Oxydrive SB QSWXK? Probably overkill for what I want although I am seriously considering a bottle battery. Looks very nice too.

I wish you could buy the 8 fun kit without battery and couple it up with a Ping lifepo4 10ah. That would be ideal.

Juicy, I didn't realise you did kits. Is it a QSWXK? Not too keen on the frog unfortunately. It will interfere with the rear rack and in my experience the frog mount only lasts about 12 months before it snaps. I got through 2 in almost exactly 2 years. Always cracked in the same place too. It would fit OK in panniers though. I'm impressed that a frog battery can now cram in 10Ah at 36V. Is it lifepo4 or is it still standard lico?

 

[Deleted member 4366]

The new Oxydrive kit has the Dapu motor. It still has the high-discharge bottle battery with the sealed integrated 15 amp controller, which is a shame because both the battery and motor can give a lot more power. I think that it would be much better at 18 amps, although even at 15 amps, it's more poowerful than the Fun kit. It's still easy to derestrict it for more speed by getting into the LCD panel settings.

 

[shemozzle999]

Thanks for all the replies.



Juicy, I didn't realise you did kits. Is it a QSWXK? Not too keen on the frog unfortunately. It will interfere with the rear rack and in my experience the frog mount only lasts about 12 months before it snaps. I got through 2 in almost exactly 2 years. Always cracked in the same place too. It would fit OK in panniers though. I'm impressed that a frog battery can now cram in 10Ah at 36V. Is it lifepo4 or is it still standard lico?

Hi Caph,

When you say the mount snaps do you mean the plastic side covers or the metal base and do you have any photo's of the damage?

 

[Deleted member 4366]

In ny experience, the plstic sides can crack very quickly, especially if you go over a lot of bumps. They break because the whole carrier works its way downwards. You can pull it back up, but after several times, the metal starts to crack, then it becomes weaker, so goes down more easily. Eventually it breaks right off. This one's well on the way. There's lots of different suppliers. Some are probably better than others:

 

[shemozzle999]

In ny experience, the plstic sides can crack very quickly, especially if you go over a lot of bumps. They break because the whole carrier works its way downwards. You can pull it back up, but after several times, the metal starts to crack, then it becomes weaker, so goes down more easily. Eventually it breaks right off. This one's well on the way. There's lots of different suppliers. Some are probably better than others:

Thanks for the photo, I now see what you all mean, I have 4 of them and as you say the quality can vary a lot. I have never had a failure yet but then again I don't off-road on the Brompton but I do run the heavy 24v,15Ah battery - always square up the folds in a vise and refit the clamp bracket tightly as most turn up loose (BMSbattery).



It seems as if it would benefit from having the top corner edges welded together to strengthen it and radius the corner of the folder to stop it shearing.

 

[Deleted member 4366]

Yes. The problem is that they bend in the middle where the 4 screws go. It''s too far from the screws to the edge so the top bulges forward as the weight pulls the back down. It needs a web along the top edge as far as the screw-holes, or the screws need to be further appart.

 

[trex]

The new Oxydrive kit has the Dapu motor. It still has the high-discharge bottle battery with the sealed integrated 15 amp controller, which is a shame because both the battery and motor can give a lot more power. I think that it would be much better at 18 amps, although even at 15 amps, it's more poowerful than the Fun kit. It's still easy to derestrict it for more speed by getting into the LCD panel settings.

maybe - the Ezee kit has 20A controller. I thought Oxygen like 8-Fun limit their kits to be strictly compliant with EN15194, that attitude is commendable in my view.
The Ezee kit has a sweet spot 25NM at 200RPM - it'd fly up most hills but anything requiring more than 25-45NM, you've got to rely on leg power, the 8-Fun can climb steeper hills on throttle.

 

[Deleted member 4366]

I've read through EN15194 and the relevant associated standards. The only requirement is that the manufacturer puts a 250w label on the motor. The wording is something like "a nominal rated power". There's no mention of maximum power nor how the manufacturer should rate it. "Nominal" means a label. You can run it at whatever current you want and have a motor as powerful as you want.

Various manufacturers have recognised this point. When I was in China I spoke with motor manufacturers about it, and they admitted that they had put 250w markings on more powerful motors for European customers.

BH Emotion are running some of their motors at 18 amps or more and, I'm sure, so are Kudos. They both have certification. As far as I know, the new powerful Emotion Neos have the same Dapu motor as the new Oxygen bikes.

There's a dependent standard for motor power testing called up by EN15194. It only requires that the motor's run at the rated power for a set time in set conditions without overheating, so if a bike manufacturer has a 1000w motor marked by the manufacturer with a 250w label, it will be run at 250w to see if it over-heats, which of course it won't, so it passes the motor power test.

 

[trex]

I understand that EN15194 allows temporary increase of power over 250W, not to be used permanently.
Nothing stops end users adding a bit of solder to increase the Amps but the the suppliers who make the effort to keep the Amps low deserve to be praised.

 

[Deleted member 4366]

I understand that EN15194 allows temporary increase of power over 250W, not to be used permanently.
Nothing stops end users adding a bit of solder to increase the Amps but the the suppliers who make the effort to keep the Amps low deserve to be praised.

As far as I can see, the only requirement is a manufacturer's label on the motor that shows 250w or less. Why should suppliers of underpowered bikes be praised?

 

[trex]

because I am a romantic and I like the underdogs and prefer efficiency to raw power.

 

[flecc]

The only snag is that the UK e-bike and EU pedelec type approval laws do specify the maximum continuous power, giving no leeway excesses.

The leeway only comes in one of the two options for testing in EN15194, the acceleration time method:

In this test, starting from a standstill one accelerates the bike, and times how long it takes to cover 20 metres. According to EN19154 the power is to be calculated from the formula,

P=2*D*D*M/(T*T*T)

where P= power watts, D= 20 metres, M= mass of rider plus bike Kg, T = time secs to cover distance D.

Therefore it's only necessary to arrange the controller's power gain for the bike to take sufficient time over 20 metres to get the calculated power less than 250 watts. For my powerful e-bikes, that needs to be just over 7 seconds, but one of them slaughters that time. I could probably do the test twice with the stop in between in that time!

 

[Deleted member 4366]

because I am a romantic and I like the underdogs and prefer efficiency to raw power.

The controller maximum current limit doesn't in any way affect the efficiency of the system, except that it can make the motor more efficient when hill-climbing. Neither does it affect the weight. It's been said before, but I'll say it again: If your system has a lot of power, you don't have to use it all. You have the option of selecting a low PAS level or low throttle position when you want to provide pedal power yourself, but if you have a low power system, you can't select high power when you want/need it.

 

[flecc]

if you have a low power system, you can't select high power when you want/need it.

Three Shredded Wheats?

 

[Deleted member 4366]

The only snag is that the UK e-bike and EU pedelec type approval laws do specify the maximum continuous power, giving no leeway excesses.

The leeway only comes in one of the two options for testing in EN15194, the acceleration time method:

In this test, starting from a standstill one accelerates the bike, and times how long it takes to cover 20 metres. According to EN19154 the power is to be calculated from the formula,

P=2*D*D*M/(T*T*T)

where P= power watts, D= 20 metres, M= mass of rider plus bike Kg, T = time secs to cover distance D.

Therefore it's only necessary to arrange the controller's power gain for the bike to take sufficient time over 20 metres to get the calculated power less than 250 watts. For my powerful e-bikes, that needs to be just over 7 seconds, but one of them slaughters that time. I could probably do the test twice with the stop in between in that time!

Your right about the UK law, but we have a sort of amnesty on bikes that comply with EN15194 plus throttles.

The acceleration test isn't mandatory. It's an alternative if the motor doesn't have a rating from it's manufacturer.