GNG Drive Gen2

[lantice13]

320kw......good luck with that. this kit is a copy of an old project here years ago converting a geared hub motor to a mid drive. it will have the same problems as a geared hub motor. give us an update how you manage to modify this to do 320kw..........

 

[gman1971]

320kw......good luck with that. this kit is a copy of an old project here years ago converting a geared hub motor to a mid drive. it will have the same problems as a geared hub motor. give us an update how you manage to modify this to do 320kw..........

LOL, it was "figuratively speaking" I meant to make it handle 22 amps like its nothing...

So, more updates on the subject. Kit got repaired, Jon wanted 28 bucks for a new shaft but it doesn't look like the shaft is the real culprit here, it was the result of what is actually wrong with it. So, after putting the motor back together I realized the motor can was actually bent; and as you can imagine, this bend eventually worked the metal and snapped it. At this point I don't think this kit is worth my trouble much longer, and in general mid-drives seem to be a an absolute PITA and a reliability nightmare; so I, perhaps, might go the cheap route of direct drive rear hub and forget about gears chains, etc etc... I want 100% bulletproof on my ebike as I plan on commuting 365 days a year (I already did on my carbon bike during summer and spring and early fall, but I am missing the winter in Wisconsin)

I will probably keep the controller and install a 1000W hub instead; that should solve most of my reliability problems... so we'll see. Tonight I'll open the motor again and see if I can straighten the can, or whatever is bent inside...

G.

 

[lantice13]

I meant to make it handle 22 amps like its nothing...

Well at 48v, 20-22amps the motor get's pretty warm.....even on dual motor mode..... that is not a good sign. hot to the touch casing on a geared hub is not a good thing as it's probably really hot inside since the stator is insulated by several air gaps, and heat cannot escape fast outside the motor casing. Can't really go wrong with a direct drive, cant beat one moving part in simplicity and reliability. Get one of those newer generation of 90% efficient DD hub motors like the 1.5kw leafmotor or a 3kw MXSUS v2 if you need high power.

 

[lantice13]

I will probably keep the controller and install a 1000W hub instead; that should solve most of my reliability problems...

Nah... just get a infenion based programmable controller so that you can tweak your motor parameters better it will save you a lot of trouble later on. 22 amps on a direct drive is anemic.....I mean I find 25-26 amps 48v on my direct drives anemic.... lol you gonna roll on low amps setup, you are better off with a geared hub motor. I am pretty satisfied with a 10T MAC geared hub motor at only 21 amps. wheelies at 23-25 amps. It should be pretty reliable as I had mine for 2 years 4k miles in it. I would not ride it in rain though as it's not sealed at all.

 

[gman1971]

Nice, thanks for the suggestion... so I might go that route then... also been eyeing the MAC motor too... and the Infinieon controller doesn't seem to bee too expensive either. The fact I don't know much about this kind of stuff doesn't make it any better... I don't even know what kind of chain this kit has... is it a #219? #50? any thoughts on that? The DD hub motor seems like a nice deal, 90% efficiency sounds great...

The worst I've managed to get my motor is just barely warm to the touch after 8 mile commute with hills. So not sure if this new Gen2 2015 motor is different than the older Gen2 motors? After taking this guy apart and inspecting I think you could oil cool this motor just fine; its nothing but an outrunner motor with a planetary gear...

Sooo , turns out the motor can was not bent after all, just bad bearings; so I replaced the rear ball bearings and the motor is close to straight as an arrow now; and rotates quite smoother than even when new.

I am in joy and go for a test ride... all good... so, when I thought my misfortune was about to end there, the shaft notch that holds the drive sprocket broke off while testing the bike.. At that moment (2 AM) I gave up and went to sleep. I managed to get 8 miles out of the straightened motor before the keyed shaft pin broke off and I did noticed around 15-20 watts less power consumption when unloaded. New it was about 87 watts unloaded (just sprocket, no chain) now it sits about 68 watts unloaded. I did notice the motor runs quieter as well... So it might be worth investing on ceramic bearings and a larger and thicker motor shaft for this guy.

Do you have an idea as to how to fix the groove where the motor sprocket holds onto when rotated? I am thinking of using the Dremel to make couple of grooves/channels and slide some chain pins to hold the sprocket in there. Surprising how bad the design on this motor is; everything just keeps breaking and needs replacement with higher grade parts. Motor shaft is definitively worthless on the 2015 Gen2s...

I am at a point in which I might have the local machine shop that fixed it and have them make me a harder, longer and splined 12mm shaft for the motor.

And the moral of this story is :drumroll: Don't be cheap like me... spend a few more bucks and get something better. So, with that said, my wife's future ebike will not be getting a GNG... no questions about that.

G.

 

[gman1971]

After doing some research looks like a Scotchman key (or round key) will do the trick to fix the axle. I have plenty of hardened steel chain pins floating around and drilling one or two should hold the gear in place under load.

G.

 

[lantice13]

And the moral of this story is :drumroll: Don't be cheap like me... spend a few more bucks and get something better. So, with that said, my wife's future ebike will not be getting a GNG... no questions about that.

I agree on that. lol been there done that. And what's another $100 for something that is known to work just fine out out of the box? http://lunacycle.com/motors/bafang-mid-drive-and-parts/bafang-bbs02-750w-mid-drive-with-upgraded-3077-controller/

 

[lantice13]

And this is what I want to replace my 2015 Gen 1 when it dies. http://lunacycle.com/motors/bafang-mid-drive-and-parts/bafang-bbshd-1000w-mid-drive-kit/

 

[gman1971]

And lo and behold.... SUCCESS!!!... I took it for a 25 mile spin this afternoon and the bike runs like a champ. Climbs like a champ... goes up to 32mph on flats... The only thing I am thinking is that I might have make a better chain tensioner, but other than that this thing finally runs and runs real well... It only took ~2 weeks, lots of cursing and about 100 extra bucks in hardware and tools to get the dang thing to work.

G.

 

[gman1971]

And the moral of this story is :drumroll: Don't be cheap like me... spend a few more bucks and get something better. So, with that said, my wife's future ebike will not be getting a GNG... no questions about that.

I agree on that. lol been there done that. And what's another $100 for something that is known to work just fine out out of the box? http://lunacycle.com/motors/bafang-mid-drive-and-parts/bafang-bbs02-750w-mid-drive-with-upgraded-3077-controller/

Indeed, 799 but its a turn-key solution... no fiddling, no tinkering, no mess, no fingers cut, no bleeding... etc... I will get either that one or the BBS02 750W one for my wife's bike when I get around to do it. I am done with bike installations for a while after the GNG hurricane.

Now, with that said I think I'll keep the GNG on my bike because now that I know exactly how it works it would be much easier for me to just upgrade/fix parts than start all over again... besides , the GNG seems more like a tinkerer (me) rig than a install-and-forget kind of setup like the Bafang, and its one of those things that once you have 22 amps, I'll want to boost to 30 amps with the shunt mod (which will be my first mod once I forget about this initial issues) then ditch the stock controller and upgrade with Infineon controller running 40 amps... then suddenly I'll be needing a new motor... and a new drivetrain... and sooner than later I'll end up buying a Hayabusa :lol:

In all seriousness tho, in addition to the GNG modding potential, I also like having two chainrings so I can still use it as a regular bike... Here is a video of the ebike... I'll post a few pics tomorrow.

https://www.youtube.com/watch?v=stTSuJlWjAc

Next mandatory mod is disc brakes, at least for the rear wheel; because my V-brakes are not going to last very long stopping the bike from 30 to 0...

G.

 

[gman1971]

Pics.

Triple chain ring

Motor back

Handlebar

 

[lantice13]

It'S OT but here is my problem child gng gen 1 2015 version build on a Commancal Meta Super 4 FS bike. took about 4 months getting it to function properly.... had to keep getting parts from China and course tuning the darn thing. you probably need to mess around with your phase amps and battery amps ratio if you are really seriously gonna keep tinkering with it. I am afraid you are gonna break more stuff after that shunt mod.

 

[lantice13]

However I don't commute with it as the reliability is not on par with my commuter bikes that got hub motors so It's pretty much a show/demonstrator bike. it does get attention due to all that chain reduction exposed and all.

 

[gman1971]

Wow, that is a good looking bike Lantice!! Nice!

I did a major rework over the weekend on the bike, mainly to get things cleaned up a bit from the prototype stage; and I also did preparation work for Cycle Analyst because the cheap 16 dollar Voltmeter died (screen faded and then it simply won't turn on)

While I don't know how well it will work as a commuter, I think at this point the bike should be better in reliability terms: with a hardened motor shaft and a local machine shop which will cut me a new hardened steel 12mm shaft that will go from both ends of the motor can, so breaking the motor shaft will be an impossible proposition. Then the Dutchman keyed main shaft, that new round pin should hold a lot of power before ever breaking, and a new KMC hardened chain; along with a thumb throttle mod for the stock GNG throttle assembly so I can feather it upon start ups.

While all the tinkering was frustrating and painful, the good thing is that at this point I don't think I'll bee needing anything from Jon anymore; I believe can fix anything on this bike now since I already know of every component that goes into it and the truth is... it aint much to it... is a big glorified RC toy, with a larger motor than the 700 class helicopter outrunners I am already accustomed to.

I did a 25 mile test ride yesterday and I commuted to work on it today; obviously I am not mating the gas from dead stops and I am using the gears quite generously to avoid bogging the motor and overtorqueing the thing.... only time will tell as far as reliability goes. But I think it should last for quite a while. I am carrying a spare drivechain and my chain tool in case I need to do some fixing on the road. The worst I feel it could happen at this point is the drivechain poping out.

For stats I am happy with it; Only using the throttle (no pedaling), My 8 miles commute, using a 48v 12Ah LiPo in pretty hilly terrain ends at 50% capacity; that's without me pedaling a single bit. This is with 30-32mph on the flats (with no headwind) and 37-39mph downhill. But I go really easy on the bike up the hills at only 16 mph; but I know it will do well over 20, but not worth the risk of added wear. I did invest on a full face scooter helmet (so much nicer than the bike helmet) and some bright orange gloves and heavy coat that are waterproof, windproof, coldproof, etc...

I have so much to learn on this, but this is kinda how it all starts; I am super happy with the bike as is so I don't think I'll be doing more than perhaps the shunt mod for having a bit of extra power reserve in the tank...

So, how many ebikes do you have? I am already thinking about building one for my son (he has a 24" Walmart roadmaster) any suggestions?

G.

 

[lantice13]

I built 5 since 2012, one was given away and another was retired but parts was taken to another bike. So I got 3 total in my fleet, 2 commuters one recreational rider. the one with the GNG gen 2 which is also have a rear hub motor is the oldest one that is still in service. I'm in an ebike build hiatus for 2 years right after the red bike was completed due to lack of funds. Next in the road map is a high power bike using either the new " BIG MAC" geared hub motor from em3ev or one of those popular 3kw mxus. Be building on one of those Stealth Bomber/fighter shaped ebike frames that are coming out the past months. for now I roll with the current lineup. :wink:

 

[lantice13]

I am already thinking about building one for my son (he has a 24" Walmart roadmaster) any suggestions?

Generally, I don't recommend motorizing an $85 bike from walmart. Looks like they are made of steel so the frame can be used for a low to medium power build 250w-1kw max, problem is that the frame is pretty much the only usable part in that bike as everything else will need to be replaced. Those parts that are on that bike might not handle the added weight and speed of a motorized bike. I would go with either a Schwinn branded bike which have limited lifetime warranties on their frames lately and Genesis bikes, but then again, you still need to upgrade a few things usually tires and brakes. my Dual motor ebike was built on top of a Genesis 29er cruiser from Walmart an that bike weigh 99 lbs after I was done. I weigh 220 lbs....the frame still sound after 3-4 years, 3k miles of use, so I trust their frames. Seems like the Genesis V2100 is a favorite for a cheap FS this year for cheap builds, but do know the limitation of a $150 FS bike compared to a $500-1300 FS bike. If This is for recreational riding, the higher priced walmart bikes should suffice with some upgrades, but as for a commuter, it's easier just to go to your local bike shop and get a bike that is already fitted with better components.

 

[gman1971]

I am already thinking about building one for my son (he has a 24" Walmart roadmaster) any suggestions?

Generally, I don't recommend motorizing an $85 bike from walmart. Looks like they are made of steel so the frame can be used for a low to medium power build 250w-1kw max, problem is that the frame is pretty much the only usable part in that bike as everything else will need to be replaced. Those parts that are on that bike might not handle the added weight and speed of a motorized bike. I would go with either a Schwinn branded bike which have limited lifetime warranties on their frames lately and Genesis bikes, but then again, you still need to upgrade a few things usually tires and brakes. my Dual motor ebike was built on top of a Genesis 29er cruiser from Walmart an that bike weigh 99 lbs after I was done. I weigh 220 lbs....the frame still sound after 3-4 years, 3k miles of use, so I trust their frames. Seems like the Genesis V2100 is a favorite for a cheap FS this year for cheap builds, but do know the limitation of a $150 FS bike compared to a $500-1300 FS bike. If This is for recreational riding, the higher priced walmart bikes should suffice with some upgrades, but as for a commuter, it's easier just to go to your local bike shop and get a bike that is already fitted with better components.

I understand that, the Response I have had good enough components to warrant the convert; but in this case my son is not tall enough yet to reach his foot to the ground on even a 26er. When he can reach the ground on my carbon bike I'll get him a nice carbon one, but until then I think the ebike is the best way to get him going as fast as I go with my road bike so we (wife and I) don't have to wait for him every few minutes on our long road bike rides; plus we can also go for ebike rides at night which is really nice.

Wel, I ended up going GNG again; the absolute cheapest kit I could find, and since I already knew what to expect out of those GNG I figured it was worth a try (a mid-drive brushed, 24v, 350w kit) for just 150 bucks shipped to my door from an US location. I figured that if we get the bike nicely done we could resell the bike later for much more than we paid for the bike and the kit combined.

G.

 

[gman1971]

I built 5 since 2012, one was given away and another was retired but parts was taken to another bike. So I got 3 total in my fleet, 2 commuters one recreational rider. the one with the GNG gen 2 which is also have a rear hub motor is the oldest one that is still in service. I'm in an ebike build hiatus for 2 years right after the red bike was completed due to lack of funds. Next in the road map is a high power bike using either the new " BIG MAC" geared hub motor from em3ev or one of those popular 3kw mxus. Be building on one of those Stealth Bomber/fighter shaped ebike frames that are coming out the past months. for now I roll with the current lineup. :wink:

Very nice! Holy smokes, 5 ebikes?

I see that you have an earlier version of the Gen2 (the smooth motor).. and I image the hub in the back also provides quite a punch to get going and gives you the ability to brake regen too...

Those stealth bomber bikes look more like motorcycles to me than a regular bike but they sure look cool... how much are the frames on those? b/c I assume they won't be cheap... right?

G.

 

[lantice13]

Those stealth bomber bikes look more like motorcycles to me than a regular bike but they sure look cool... how much are the frames on those? b/c I assume they won't be cheap... right?

Cheapest one is around $600 from em3ev or from aliexpress, also there is the vector frame from Ukraine for around the same price, then the Quilbx raptor frames that are around $800 to $900, then the flux alpha and flux beta from the guys from stealth which are around $1500.

 

[lantice13]

Wel, I ended up going GNG again; the absolute cheapest kit I could find, and since I already knew what to expect out of those GNG I figured it was worth a try (a mid-drive brushed, 24v, 350w kit) for just 150 bucks shipped to my door from an US location.

Aw man hopefully you didn't get the bb mounted version as that thing is a piece of crap... only lasted 1 week and it fell apart.... not over volted or anything, stock 48v. The design is just bad. tried to repair them but as I try to find solutions to fix it, the more I find issues with this kit. so in the end, I just toss it and went with a hub motor. this is my very first experience with a GNG kit....hopefully you can refund your money and just get a geared hub motor. you can get those for around $250, those Bafang BPM II and CST II should be more reliable and easy to ride.

 

[gman1971]

Thanks for the heads up, that confirms what I suspected... the bottom ones sucked...

This is what I got:
http://www.ebay.com/itm/DIY-Electric-Bike-Conversion-Kit-36V-350W-Geared-Brush-Motor-Cycling-Accessories-/161858536121?hash=item25af8542b9:g:ni0AAOSwo6lWHxFn

Well, looks like its very close to yours... This will be run at 24v, so not much power really, and I would prefer not to spend too much on a 24 Roadmaster Walmart bike... I shuffled the idea of a hub motor at first (considering the issues I was having with mine), but the problem is that after the bike is gone I will have to take the hub out and learn how to respoke a new larger rim to put the hub motor. This mid-drive I can just sell with the bike since its inexpensive enough.

On another note, I disassembled the GNG Gen2 v2 motor to see how it was holding up and nothing seemed to be bent or broken inside. I think making the shaft longer and harder has probably helped the situation quite a bit too. But like I said, worst comes to worst I'll be drilling the case and installing a solid 12mm shaft across... that will basically make the motor nearly indestructible to regular use... but so far looks like the hardened shaft is holding well. No bends, no wobbles etc.

After I inspected the motor I went ahead and filled it with ATF fluid, maybe about 1/2 cup of it; and then went to run it... it quieted the motor enough that I could notice and also ran cooler after the 12000 mAh test ride at WOT. The bad news is that (as I suspected) it needs sealing to hold the fluid inside so I'll be taking care of that this weekend, it was no more than just little dripping, but enough to warrant full sealed motor. Have you tried oil cooling yours?

We'll see how the new GNG-clone holds together (I should have it on the 10th) I also ordered this little guy as a power meter.
http://www.ebay.com/itm/171924972351?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

G.

 

[gman1971]

Thanks for the notes you took on the pictures of your first install.. I'll make sure these issues are addressed once I get the motor.

Thanks!

G.

 

[gman1971]

Another entry on this saga...

The crank freewheel broke off, (how surprising, right?) so I have a e-motorcycle now, not an e-bicycle anymore.... TERRIBLE.

So to kinda sum this thread up.

AVOID THE GNG Gen2 2015 kit like the plague.

Lets hope I can fit the Cyclone 3 chainring crankset on the bike.

G.

 

[lantice13]

told you so.... anyway, you can get another freewheeling crank that got ISIS hardware either from LR mid drives or from Cyclone Taiwan. Or buy those older version of that freewheeling crank-set from gng....

 

[gman1971]

told you so.... anyway, you can get another freewheeling crank that got ISIS hardware either from LR mid drives or from Cyclone Taiwan. Or buy those older version of that freewheeling crank-set from gng....

I know you did, and I am sucker for not believing it... Why is it that everything in this kit is so substandard?

Jon now wants to send me a new part at no cost, well, thats after I finally got feed up and put a PayPal complain for selling defective items; I am asking for a partial refund because fixing their kit is costing me money; and not cheap to fix.

And then, I am not even sure what the heck part he is trying to send me... at this point I think I am going to get some refund b/c its unacceptable that after paying 450 dollars the kit falls apart with just a few hundred miles of regular road use.

G.