GNG Crank-drive kit

[Deleted member 4366]

My 450w 48v GNG crank-drive kit arrived today. That's less than a week from order. No duty to pay, so £270 for the kit without battery. I'll try it at 36V first with one of my own controllers for lower power. Photos to follow.
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[eddieo]

while looking for a Panasonic motor for other member, came across this interesting mid motor on German ebay.... weaker I guess at 24 v

Pedelec

 

[flecc]

while looking for a Panasonic motor for other member, came across this interesting mid motor on German ebay.... weaker I guess at 24 v

Pedelec

Looks like the Japanese Sunstar SO3 kit Eddie, replaces the bike's existing bottom bracket and combines it with a torque sensor.

 

[amigafan2003]

d8veh - GNG have confirmed the controller can take upto 63v (15s lipo) batteries

But you'll not be able to pedal fast enough with a 63v battery! You could swap the freewheel on the motor out though to bring it back in line.

Discussion on endless sphere suggests motor can take the extra watts too.

 

[amigafan2003]

Oh, and before you fit it d8veh could you weigh it?

 

[NRG]

Looking forward to this one! Pics please !

 

[Deleted member 4366]

d8veh - GNG have confirmed the controller can take upto 63v (15s lipo) batteries

But you'll not be able to pedal fast enough with a 63v battery! You could swap the freewheel on the motor out though to bring it back in line.

Discussion on endless sphere suggests motor can take the extra watts too.

Yes, I read all that. They're also discussing how to strengthen the drive-train for more power, but I want to find out if it's any good for mere mortals before thinking about that. I want commuter/touring at 15 to 20mph with good hill-climbing rather than 40mph motor-cross.

I reckon it should be ok at 36v. I pedal at a cadence of 70, so a no-load speed of 98 should be perfect for maximum power and efficiency at my speed. From memory it was 125 at 48v, so 36v should give 93. I'll let you know later after I've done some tests. I'm not convinced that the chain and gears will survive too long even at 36v.

 

[Deleted member 4366]

All finished and tested now. Since I encrypted my phone, I can't see my photos on my PC, so you'll have to wait a bit for them.
Fitting took about 2 hours, but that was mainly changing tyres and discs so that I had a usable bike. It's a lot simpler than a hub-motor: off with the BB; on with the motor; screw on the pedals; add the chain; wire up the controller.

The bike I used already had a 10aH LiFePO4 battery and KU93 22amp controller plus throttle fitted. It had a Q128 m0tor and was running at 25 amps (soldered shunt)m and it could just get up our short test hill with a bit of pedalling in first gear.

I started at the bottom and the bike charged up the hill, so I hit the gear changer again and again. The motor didn't even slow down by the time I reached 4th gear. This thing climbs better than a 500w BPM at 40 amps. I can't imagine what it'd be like at 48v!.Don't forget, this power came from a 36v 10aH battery.

After several runs, the front bearings in the wheel collapsed - nothing to do with the motor - and it started to rain, so I didn't get more chance to really see what it could do.

It's not very refined. It's more noisy than your average bike, but I need to adjust chains and things to give it a fair report, but I can tell you that it has immense power - at least twice as much as a Bosch and maybe three or four times, and that's at 36v.

In summary: Refined it isn't. Power and torque it has in spades. £270.

 

[Old_Dave]

Great report d8veh

I only hope my 350W 36V kit from the same stable is % wise as nice


Sent from my iPhone using Tapatalk

 

[amigafan2003]

So noise - and I know it's subjective - is it an "omg everyone is going to stare at me and wonder what the hell I'm doing" noise or is it a "this is pretty noisy but I wont feel self concious riding it and wind noise is louder anyway" noise?

 

[vhfman]

I have started work on another mid drive bike using the GNGELECTRIC brushless motor kit.

mid 450W (brushless)

I got the 48V 450 Watt kit, but I am using a 36v controller with a 12S 9Ah A123 battery.

I have rotated the motor body round so that the cable entry point is not at the bottom of the motor where it was possible to get damaged if hitting some obstacle. And I have changed the drive chainwheel from 38 to 44 which has improved the pedalling cadence at higher speeds. The drive is into a Nuvinci N360 hub.

The chain tensioner spring on the motor drive I think was too strong, so I replaced it with a lighter spring which seems much better.

Here are some photos of the BB motor and the quick test setup on the bike.
The motor feels a bit slower and weaker on the lower voltage 39V instead of 44-49V but it still produces enough to pull up quite steep slopes peaking about 800W. But I have not had the time to really test the system out fully yet. The drive is not quite but produces less noise than the Cyclone motor I have been using. And the motor to pedal cadence is better at normal 15-20mph speeds.

I will be moving the controller and tidying the wiring just in time for the Autumn/Winter weather but I hope to get out ridding when I can.

Chris

 

[Deleted member 4366]

Here's spme photos:
This is what you get. The motor is 4.3kg. I reckon the additional weight to a bike not counting battery is 4.9kg

Finished bike:

 

[Deleted member 4366]

The noise is not excessive. I have other noises from my bike so it's difficult to say, but it's more than a hub motor, but not by much. A bit of oil on the chain will make it quieter too.

The only non-standard thing I did was fit a pedal sensor. The controller has a connector but no sensor provided. To fit the one I already had, I had to grind a bit off the bracket to allow clearance:

 

[hech]

well done d8vey, I'm glad someone has the time, money and ingenuity to explore these possibilities and then the public spirit to explain them. It would be good if vhfman could do the same regarding his experiments with the nuvinci drive which may also be a revelation for future ebike designers.

 

[hech]

All finished and tested now. Since I encrypted my phone, I can't see my photos on my PC, so you'll have to wait a bit for them.
Fitting took about 2 hours, but that was mainly changing tyres and discs so that I had a usable bike. It's a lot simpler than a hub-motor: off with the BB; on with the motor; screw on the pedals; add the chain; wire up the controller.

The bike I used already had a 10aH LiFePO4 battery and KU93 22amp controller plus throttle fitted. It had a Q128 m0tor and was running at 25 amps (soldered shunt)m and it could just get up our short test hill with a bit of pedalling in first gear.

I started at the bottom and the bike charged up the hill, so I hit the gear changer again and again. The motor didn't even slow down by the time I reached 4th gear. This thing climbs better than a 500w BPM at 40 amps. I can't imagine what it'd be like at 48v!.Don't forget, this power came from a 36v 10aH battery.

After several runs, the front bearings in the wheel collapsed - nothing to do with the motor - and it started to rain, so I didn't get more chance to really see what it could do.

It's not very refined. It's more noisy than your average bike, but I need to adjust chains and things to give it a fair report, but I can tell you that it has immense power - at least twice as much as a Bosch and maybe three or four times, and that's at 36v.

In summary: Refined it isn't. Power and torque it has in spades. £270.

hey d8vey, without meaning to dampen the excitement of your discovery mebe you should point out that these are all just electric motors with cogs and sprockets, german or chinese, which can only give out what they take in from generally rather expensive lithium battery packs.

 

[Deleted member 4366]

I had another go later with a 36v 15 amp controller. It got up our test hill slowly in first gear - about the same a my Bafang hub-motor crank-drive. The extra 10 amps that I had before made a massive difference. I wonder what's the amp rating of the motor and supplied controller. I think I'll ask on ES.

 

[hech]

well dav7i an extra 10amps means 360watts doesnt it so it would, wouldnt it? by the way my tonaro that i pulled outtA A SKIP FOr 5 BOB CLIMBS OUR TEST HILL IN 9TH GEAr at 32mph!

 

[Deleted member 4366]

I had a go with 12S lipos today at 48v. It's now more like an electric moped - no point in pedalling because you need all your concentration for driving it. It's difficult to stop it wheelying in first gear, but it pulls away from a stand-still in top gear, so that's much easier. If you want power or speed, this has to be the one. There's nothing can touch it for the money. Personally, it's too much for me.

I also tried it with 15amp 36v controller, which made it fee more like a normal electric bike. It's half the power but feels a lot less

 

[amigafan2003]

Hmm, thinking 44.4v 12s lipo and programmable controller to bring the amps back down.

What's the top speed like? Anything more than about 24mph on my mtb and I could keep up pedaling.

 

[hech]

Yup okay, we may be departing from conventional norms of the pedelec comfort zone but this isn't a moped nor a smelly, nouisy xc motorbike, it is a normal bicycle with, well, phenomenal assistance which can drive you up the roughest steepest dirt tracks and mountain paths without bothering the sheep! Hill-walking will be ancient history.