GNG, 1000W 48V BB-drive, $400

[flyinmonkie]

Hub motors went through the same progression until people found hubs that would withstand over volting them. I haven't hear of the motor melting yet on a gng kit. The belt is what goes and that is far cheaper and easier to replace than a motor or controller. Those over volting aren't surprised when they break. They are letting others now their journey and what they have done to improve this very affordable set up. In fact I believe several said lets see what this set up can take.

It is sold as a 450w set up, but has been found to see peaks of around 1000w with out changing anything. I have seen one post of 1000ks before the belt broke when run stock, though this seems uncommon. There are several running it at 36v and have no problems at all with the stock set up.

No it isn't the best designed set up, but it allows more people to get into a quiet mid drive at a reasonable cost. Even including changing a few things. At least you get a solid motor that fits between the cranks and the basic mounting brackets are better than the cyclone ones. A step in the right direction.

Clay

 

[Jackrabbit]

Dear jackrabbit. I see this is your first post. Welcome to ES!

As you can see we are like a family here, and many of us have strong opinions that sometimes result in vibrant discussions. Don't take it personally. You are in the right place...

Thank you for your kind welcome.

I'm not in the least bit offended It was no surprise when the belt died (I have several spares). I have some of your adjustable plates on the way via my brother and a chain conversion was planned before the kit arrived. I've fitted a three speed switch and in position 1 it's similar to the stock output. I'll step up the power when I've made the driveline a little more robust.

In the mean time I intend to have a lot of fun on it.

 

[skyungjae]

I'm starting to wish I had gotten the 400w Gen 2 brushless kit. Having that belt drive on one side and an axle going to the other side is a bit complicated. Well, with all the spare parts that I'm generating with my 450w brushless, I may just buy a gen 2 motor and controller for a second bike. :wink:

 

[querlenker]

Hello,

is there anybody using the stock controller with 60V?
Whats the best controller setup for 60V or 72V

Thanks!

 

[spinningmagnets]

It was no surprise when the belt died (I have several spares)

jackrabbit, If you are keeping the stock 14T motor-pulley, I'm told it helps belt-life a lot to sand/file down the rough and sharp edges of the teeth. I highly recommend the $120 Thudbuster, sounds expensive...until you actually try one on a hardtail frame.

I am recommending this kit to local NON-hot rodders at 36V X 21A = 750W, which requires a new controller (due to the stock controllers LVC), but...the 36V battery is cheaper than the 48V, so it evens out. The minimum mods I recommend are to smooth the motor-pulley teeth and add the affordable primary plates that allow you to throw away the horrible primary belt tensioner.

If you are certain you want to use more than 48V X 25A = 1200W, the stock belt is too narrow at 15mm to survive for any reasonable length of time. The #25 chain upgrade appears to be the most popular primary upgrade, found here: http://endless-sphere.com/forums/viewtopic.php?f=28&t=46738, many thanks to denisesewa for the great pics documenting the #25 chain upgrade.

 

[speedmd]

Back to the bent axle/shaft. Did this bend from too much chain load or hitting /crashing into something hard?

 

[Tom Tom]

Does $268. shipped to USA seem high for a gng 450w brushless replacement motor/controller combo seem high?

 

[justlooking]

Does $268. shipped to USA seem high for a gng 450w brushless replacement motor/controller combo seem high?

i payed £260 in the uk for one of these gng kits ,,

$268 = £170.49 sounds good to me. i wish i got mine for that ,,,,

 

[Tom Tom]

I think the entire kit is about 428 shipped to US. I wanted to buy just the motor/controller-thats where the 268 came from.

Anyone know of a source for just the motor or something comparable? I'm wanting to build a light weight middrive of around 1000 watts.

 

[full-throttle]

I am recommending this kit to local NON-hot rodders at 36V X 21A = 750W, which requires a new controller (due to the stock controllers LVC)

Can these local non-hot-rodders use a soldering iron? I can tell you which resistor to change. Might be easier than changing the entire controller.

 

[d8veh]

I am recommending this kit to local NON-hot rodders at 36V X 21A = 750W, which requires a new controller (due to the stock controllers LVC), but...the 36V battery is cheaper than the 48V, so it evens out.

GNG also sell it as a 36v version, so nothing to mod and nothing extra to buy.

 

[spinningmagnets]

It "looks like" a GNG buyer can substitute GNGs 9-FET 36V controller in place of the 9-FET 48V controller at no extra charge, however, this has not been verified yet by anyone.

full-throttle, If you have the time, it would be great if you could take a high-res pic (with low-res thumbnail) of the stock controller guts, and then put a red circle around the resistor that will change the LVC, and post it here: http://endless-sphere.com/forums/viewtopic.php?f=28&t=46891

It would also be great if you could include a purchase link to a specific resistor that is a drop-in replacement. Digikey and Mouser seem to be popular and trusted sources. Thanks in advance.

 

[Denisesewa]

I am recommending this kit to local NON-hot rodders at 36V X 21A = 750W, which requires a new controller (due to the stock controllers LVC)

Can these local non-hot-rodders use a soldering iron? I can tell you which resistor to change. Might be easier than changing the entire controller.

I am very interested to know how to change the LVC on a stock controller, I'd like to up it to around 44 volts to run with 14 s. any info on this would be greatly appreciated.

 

[guyavitov]

Hi Guys,
Im new here.

I built yesterday this kit on Specialized Big hit 2008, using 20S Lipo (74v) (26" rear wheel)
with Lyen's 12 Fets controller.

I received the kit with belt tensioner (from the factory)
I drove yesterday and today about 20-25Km, So far no issues what so ever with the belt!
the controller is limited to default settings (37A max)

I have lots of parts ready to be installed for making this kit heavy duty, but im waiting the belt to show some wear, so far - none.

What did you do with your's to get it wracked fast?

 

[spinningmagnets]

Welcome guyavitov! I hope GNG has been improving their kit parts. Maybe you have better parts than what they were shipping a couple months ago. The previous stock controller was verified to produce a max of 22A. Best of luck!

 

[full-throttle]

My controller is slightly different to denisesewa's but the technique is the same

The two red circles show R1 and R2. Ignore the unpopulated footprint in the top area of R1 for a moment, I'll get to that later.
The important bit is R1 is closest to the red wire and R2 is closest to GND.
LVC is simply a voltage divider that converts battery voltage into something the controller can read.
In this case the voltage divider is Vlvc = Vbatt x R2 / ( R1 + R2 )
Once this voltage drops to 3V the controller shuts down. Rewriting the equation above LVC will trip when Vbatt = 3 x ( R1 + R2 ) / R2
Notice R1 reads 1502 and R2 reads 1201. To get resistance simply write down the first 3 digits followed by zeroes equal to the last digit. Eq R1 is 150 0 0 = 15kOhm and R2 = 1.2kOhm
Substituting real values into the second equation LVC vill trip when Vbatt = 3 x (15+1.2)/1.2 = 40.5V

So to lower LVC to use with 36V one can either decrease R1 or increase R2.
To raise LVC do the opposite.

Now the tricky bit - to change LVC for a 36V pack simply solder an 0805 39kOhm resistor in the unpopulated footprint in R1 circle. That's it.
To raise LVC to 45V solder a 10kOhm 0805 resistor on top of R2.

 

[spinningmagnets]

Thanks full-throttle! that is very helpful...

 

[d8veh]

It "looks like" a GNG buyer can substitute GNGs 9-FET 36V controller in place of the 9-FET 48V controller at no extra charge, however, this has not been verified yet by anyone.

Jeez, how many times do I have to say it. That's exactly what I have and it works perfectly.

It gives about the same power as a 350w Bafang BPM (at 36v) with the same current (22A), but it can climb steeper although more slowly, and it's faster downhill.

I also tried it with 12S lipos with that 36v controller, and the power went up to about the same as a 500w BPM (at 36v).

 

[gorach]

D8veh are you saying that the 500w bpm is somehow more powerful than the 350w bpm running at the same voltage and current?

 

[t3sla]

http://topsecretev.blogspot.com.au/2013/02/gng-450-watt-brushless-hard-start-up.html
Slip Clutch idea

 

[Cyclebutt]

http://topsecretev.blogspot.com.au/2013/02/gng-450-watt-brushless-hard-start-up.html
Slip Clutch idea

This is what I like about this thread. Sure, this kit leaves a lot to be desired as a plug-and-play, but we are the experimenters. Push it till it breaks, fix that, push it some more. Every problematic area of this kit has been explored. Great work everybody! Keep us posted on longevity, please. I'd like to know which modifications have had a lasting effect.

New belts arriving today, will install adjustable sheets and post result next week on the "Primary Drive" thread.

Bike on!

 

[gorach]

What size (guage) are the phase wires on the GNG?

 

[full-throttle]

What size (guage) are the phase wires on the GNG?

2.3mm (11AWG) incl insulation
19 x 0.4mm = 13~14AWG equivalent

 

[flyinmonkie]

http://topsecretev.blogspot.com.au/2013/02/gng-450-watt-brushless-hard-start-up.html
Slip Clutch idea

Pretty sure I suggested that back near the beginning of this thread when everyone started talking about having belt issues. If it works for recumpence's 10kw RC drives, it ought to be a treat with the GNG. Especially with lightingrods adjustable sheets. I am amazed it has taken so long for someone to try it.

Clay

 

[Denisesewa]

http://topsecretev.blogspot.com.au/2013/02/gng-450-watt-brushless-hard-start-up.html
Slip Clutch idea

Pretty sure I suggested that back near the beginning of this thread Clay

Yes you did !