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

[t0me]

I didn't get any slip until I changed to Lightning Rod's top adjustable plate set. Removing the primary side idler was the problem I think.
Adding the shunt mod to up the maximum amps to a nudge over 30A didn't help.
In my case as I want to do more XC and possibly some DX, the primary chain mod made the most sense.

 

[Joe T.]

New to the forum and new to Ebiking. I first discovered Ebikes on the Internet about 3 weeks ago. I was discussing dirt bikes and noise with my nephew. Back in the day you could ride everywhere on trails around here. Now everything is no motorized vehicles only. I told him all he needed was a silent dirt bike and he could ride it just about anywhere. Well it turns out there are electric dirt bikes. I figured there must be electric bicycles as well and here I am.

I bought a GNG 450W kit and installed it on my bike. Bought an eZee 48V battery and got it all together Monday night. It's a blast. My plan was to build a bike from scratch for this project. However it installed so easy I think I'll ride out the summer like it is. The new bike will be a winter build. I have a few questions.

It seems everybody runs huge power on their bikes. How fast are you all going?

I chose a mid drive kit because I wanted a wide range of gearing. I caught a stick in my chain yesterday and mangled the derailleur like it was balsa wood. Is there an affordable transmission / hub with internal gears out there?

 

[comradegerry]

Hi Mike

My plan was always to get my Greyborg up and running at 48v with an Astro 3210, 10 turn, and Matts 2 stage reduction drive. This now works just fine running through the gears in a Shimano Alfine 11 speed rear hub. I just have to pedal to get it going to avoid synchronization stutter and take the ramp up nice and easy as the rear hub is not that strong. On the flat, 7th gear is fast enough to be scary on all but a wide open space.

There was a long point in time when I could not get the Astro to spin up properly because I did not realize that there was a bypass loop to an antispark connecter in my circuit.

In frustration I decided to buy the GNG kit to just get on the road and to try to trouble shoot the problem. Due to my bike having the swing arm at the bottom bracket I had to come up with another mount solution so I had a stainless plate welded to the frame with 4 slightly elongated holes, for adjustment and a new stainless bracket made to hold the GNG in a central, vertical plane to the frame. I had it all mounted up and had the same bad motor turnover. Forum member "Steevil" pointed out my school boy electrical error and I got the motor to spin up properly.

That allowed me to go back to my plan A and get the Astro up and running.

Having gone to the trouble of fabricating a custom bracket and welding a mount plate on my frame, I will run with the GNG kit at some point, I am just not in a hurry as the bike is up and running, which only took 2 years. There is an RC Greyborg build thread on the Sphere which slowly documents this painful and expensive learning process for those suffering from insomnia.

I think the GNG kit is great value for money and a neat compact solution, I do look forward to testing it in due course.

 

[fabiograssi]

skyungjae:

I have one kit, in use.

Just trying to upgrade. The kit comes with one, but is crap. And I am running with 48v 40 amps, and my axle starts to bend. Because of the volts and amps I am running, I think I can use a bigger chainring for motor, to improve top speed, so I think this is the moment to upgrade.

It is not a good idea, this parts?

- Fabio

In this page:

http://bikemotive.myshopify.com/collections/ebike/products/freewheeling-crankset-for-ebike-bikemotive

What is the best combo for the gng kit? And which model of central movement should I use with it?

BR,

- Fabio

What are you trying to accomplish over what the GNG already comes with?

 

[Tinto]

I can't comment on the bikemotive gear (although it looks great) as I haven't used it, but take a look at the cyclone ISIS crankset Fabio.

A few of us have switched over to it after our GNG cranksets became wobbly, started slipping then spun on the spot after a short period of time.
Mine did that and I was commuting on smooth roads - nothing offroad whatsoever.
I have switched to the cyclone kit and it has been great for about 150km of commuting at 48v/20a.

http://cyclone-tw.com/order-chainwheel.htm

 

[fabiograssi]

I can't comment on the bikemotive gear (although it looks great) as I haven't used it, but take a look at the cyclone ISIS crankset Fabio.

A few of us have switched over to it after our GNG cranksets became wobbly, started slipping then spun on the spot after a short period of time.
Mine did that and I was commuting on smooth roads - nothing offroad whatsoever.
I have switched to the cyclone kit and it has been great for about 150km of commuting at 48v/20a.

http://cyclone-tw.com/order-chainwheel.htm

Excelent! I miss that in this thread?

Thanks!

Fabio

 

[deepfraught]

Is there an affordable transmission / hub with internal gears out there?

Welcome Joe, congrats on the quick success getting onto a good thing.

There are some nice affordable internal geared hubs these days (providing you have some mechanical sympathy, no-load shift between gears) and lots of cheap donor 24 x 3" and 26 x 2" wheeled bikes with them OEM fitted that you can pick up cheaper than getting new components for the wheel/shifting alone. Electra, Felt, Schwinn are a few with cruisers in the 24 and 26 wheel size that carry 3, 7 and 8 speed internal geared hub options you can pick up cheap Shimano Nexus donor bikes of.
Look for shift mechanisms inboard of the dropout, not with a shift head adjustment protruding out of right axle nut to get smashed offroad.

I have a Shimano Nexus 8 in in a 26 x 4" fat sand bike, the update to that hub a Shimano Alfine 8 in a 700x37/32c new winter commuter, an older Shimano Nexus 7 in a Felt MP cruiser with 26 x 2.2", and a little aside a Sturmey Archer 3 speed crank geared sequential back sh ift in the Strida Evo 3. I have used the Nuvinci N360 in a mid-drive e-bike, but did nont like it at all and sold the bike. It doesn't magically shift smoothly under load as it was suggesting, there is an auto-shift system to make it more like conventional stepped shifting system, but adds another layer of potential faults to an already expensive system.

I just saw some hard tail shaft drive internal geared hub bikes today, and thought with no chain standard, a mid drive motor kit driving retro-fitted hub chain drive sprocket would only need one simple motor final output shaft freewheel Keep your pedal cadence on shaft gearing, and doesn't matter what the motor does on throttle other than aim for max efficiency.

 

[Joe T.]

I caught a stick in my chain yesterday and mangled the derailleur like it was balsa wood. Is there an affordable transmission / hub with internal gears out there?

I guess I should ask: Should I explore a geared hub over a conventional cassette & derailleur? I road the bike today and have not had any chain issues. I'll chalk up it up to bad luck. I had a lot of fun climbing the hills today. I pedal about 2-3 gears taller on the hills with "power assist" and it's like I'm on steroids. Not sure on my ultimate power for the future but what I have now seems like it gets the job done.

What are the limits on the chain for a stock type of Mt bike? I have been gentile on the throttle at this point. My rear tire slightly rubs the swing arm and it changes as I give it throttle so I know there is flex. I built my current bike thinking only in one dimension. I overlooked the flex from the handle bars and the bottom bracket. This oversight won't happen again. Just collecting data at this point.

Thanks for the reply.

 

[Anthony King]

I am interested in this kit and I've read quite a few pages of this thread, but if I could get experienced opinions whether it would suit my needs I'd appreciate it.

I'd like to add an e-assist to my Surly Big Dummy. Primary intended use for the bike is trips into town for groceries and livestock feed, the route is 12.2 miles (about 3 miles of pavement and 9 miles of a railbed trail). I'll sometimes have my kids on the bike. Total bike, rider, passenger and cargo weight would max out around 450 pounds, but would often be significantly less. The route is flat along the railbed trail, of course. The paved section before the railbed trail and my home is a 2 mile hill with an average grade just over 4%. I'm not looking to go very fast--especially with kids on the bike--but I could really use some help climbing the hill on the way home. When heavily laden if I could average 12mph and make the trip to town in an hour I'd be happy.

I keep coming back to non-hub motors because I swap wheels on the bike to make tire changes more convenient--I also use the bike to carry my chainsaw and gear when cutting firewood on our woodlot. I use DH knobbies for this and have another wheeslet for pavement and gravel/dirt paths.

Any suggestions about the suitability of this kit for my use appreciated. This is my first conversion. If this kit is appropriate, voltage suggestions also appreciated.

Thank you.

 

[kifukarider]

I chose a mid drive kit because I wanted a wide range of gearing. I caught a stick in my chain yesterday and mangled the derailleur like it was balsa wood. Is there an affordable transmission / hub with internal gears out there?

I created a spreadsheet with many gearing options (http://endless-sphere.com/forums/viewtopic.php?f=28&t=51263). There aren't prices in the spreadsheet, but they are sorted by number of gears and so relatively sorted by ascending price. I am personally attracted to the Sturmey Archer 5-speed IGH with drum brake. If money wasn't a concern, the Rohloff would be the obvious choice. I think you could tow a car with the Rohloff if necessary given the gear range. I've read that the Rohloff is near indestructible even when mistreated (shifting under power). The Sturmey Archer will not tolerate shifting under power and will fail according to an Amazon review.

I just bought a Shimano rapid trigger shifter which I prefer over twist shifters, so I'm sticking with my derailer for the time being.

 

[kifukarider]

Hi Kifukarider

I have done zero miles with the stock GNG setup, strange as it may sound, I want to improve it before I have even used it!

I have a different motor setup at the moment and want to fine tune that one first, then do a back to back comparison.

The GNG is back in a spares box but ready to install if I break the current Astro 3210 setup.

I had already started down one road when the GNG kit came out so now it is a plan B of sorts, it will see active duty at some point though.

I hope this makes sense.

Your Astro 3210 setup sounds very sexy and is one of the motors I first considered. If it looks anything like motomoto's http://endless-sphere.com/forums/viewtopic.php?f=28&t=25193&p=367633#p367633, it will surely be a source of envy.

My question regarding your GNG belt maintenance concerns was mainly to get real world anecdotes. I've found that the GNG is a great kit. Two years is a long time for a custom Astro build when a GNG kit only takes days or weeks if you include shipping time.

 

[skyungjae]

Funny that we had been talking about belt longevity. Mine starts to skip now at 1300W at when it's really trying hard up some of these steep hills. It doesn't skip at lower power yet.

I'd like to see if I can get to 750 miles on the original belt before it snaps or skips at any wattage.

 

[Wishes]

Funny that we had been talking about belt longevity. Mine starts to skip now at 1300W at when it's really trying hard up some of these steep hills. It doesn't skip at lower power yet.

I'd like to see if I can get to 750 miles on the original belt before it snaps or skips at any wattage.

Keep one in your back pocket along with the tool to replace it. Cause once it starts to skip, even a little, it goes pretty quick. Below 1500 Watts, i found that my straps did not snap, just skipping teeth. But above 1500 Watts, I"ve completely snapped and shredded belts.

My first belt lasted barely 500 KM at the 1000 Watt stock setup. That is impressive that you made yours last that long.

Wishes

 

[skyungjae]

Funny that we had been talking about belt longevity. Mine starts to skip now at 1300W at when it's really trying hard up some of these steep hills. It doesn't skip at lower power yet.

I'd like to see if I can get to 750 miles on the original belt before it snaps or skips at any wattage.

Keep one in your back pocket along with the tool to replace it. Cause once it starts to skip, even a little, it goes pretty quick. Below 1500 Watts, i found that my straps did not snap, just skipping teeth. But above 1500 Watts, I"ve completely snapped and shredded belts.

My first belt lasted barely 500 KM at the 1000 Watt stock setup. That is impressive that you made yours last that long.

Wishes

For normal riding the rest of today, it hasn't skipped at all. I do carry a spare belt with me at all times just in case. I'm pretty sure it's skipping on the part of the belt one of my friends did an accidental wheelie on. :lol:

Edit: Tightened the belt. It's all good again.

 

[speedmd]

Finally, I got mine running. What a blast! Impressive little motor, and chain primary drive is much more silent than anticipated. A bit of torque is seen in the mount and will keep a close look at it for adding a torque rod to the front plate/frame and make sure it is not just something a bit too loose. Not a chance the little belt would have held up to what I put this bike through just in the first few miles. Bit of a pain getting the front derailleur working well with the three rings and the compact swingarm, but it works ok now! It pulls the 53 /13 on gradual down hills to some serious cop alerting speeds. You can over cook the turns in a big way very easily.

Coasts forever and near silent-fantastically efficiently. Full suspension is great also. Glad I spent the time/$$ on the mechanical changes.

Things are still taped up and wire tied temporarily and will post some photos as soon as I take some and find a place to host them. Great commuter bike.

Now (after the yard work is done ) back to thinking/working on controller mods/upgrades and possibly also a CA.

 

[Haste]

So now that everyone has dissected this kit...is volts or amps more important for getting more top end out of this kit.

If I want a reliable 35mph commuter, is this kit still out of the picture? Anybody race a direct drive or geared hub?

 

[spinningmagnets]

Since this kit allows the motor to use the bikes gears, it can downshift to climb really steep hills, while still keeping the motor RPMs up in it's efficiency range, instead of bogging down and creating a lot of motor/controller heat. The downside for performance is that we are limited to the amount of power that a bicycle chain can survive.

Christerljung has used 72V X 30A = 2,100W sucessfully, but if you raise the amps any more, you make begin seeing rapid chain and sprocket wear.

The benefit of the rear hub-motor is that they can run very quietly, and also the only power limit is how much power you can afford to feed it. If a 9C gets too hot, move up to a hub with more copper mass, like the HT3540. If that still gets warm, move up to the 4065, and after that the Cromotor. If you used a Cromotor as a non-hub at 72V X 80A = 6,000W...it would break bicycle chain and shred sprockets.

If your wallet can only afford a pack that is about 15-Ah of 72V, I believe the GNG (with the recommended upgrades) would have a broader range of performance and would run more efficiently than a large rear hub.

 

[speedmd]

Just did the shunt mod on mine. WOW! Wheelies like crazy now. Third gear easily and even in forth if you tug on it a bit. In second, I instinctively kept looking for the rear foot pedal brake as the torque comes on so quick and the stock throttle does not respond in time. Goes right up past 30mph now in no time at all. Great all around city / country / commuter bike. Dog hates this bike. Must be making some high pitch sound.

 

[speedmd]

If I want a reliable 35mph commuter, is this kit still out of the picture?

If you want to get to 35 mph consistently, 12s is not going to be enough for this kit. Mine tops out just over 35 on 12s lipo with my chin to the bars and will not hold it if road rises a bit, no matter what gear its in. No doubt it can do it with more cells, but not sure how long or steep before it will cook. Regardless, 35 mph is much too fast for most stock bike frames, so be careful with your build. Even my stretched out fully suspended c'dale does not feel very safe and comfy above 30 mph if the surface is broken up much at all. Will take it part way up my favorite hill ride today if weather clears and see what it tops out at on the long hills gradual run out.

I would say now that I have ridden it a bit, it is best suited for folks that face some very steep or unpaved sections on their daily route and don't care to go much over 25-28 mph on the flats. If your ride is flat, a simpler more powerful hub motor setup may be best.

 

[Secret1511]

@Lightningrods. How is the progress with the wider pulley?
I am doing a belt in the week with 2500 watt.
Please let us know

 

[Wishes]

Has anyone worked out the color coding of the gngelectric 450w brushless wires? Anyone know how the colors for the HAL sensors? Which one is sensor A, B, C ect...?

I searched but could not find a specific reference to it.

Wishes

 

[bee]

The GNG has the green and blue reversed, after you swap the green and blue cables on the phase and hall wires, you can run the motor on other controllers like Lyens. Hope that helps!

 

[Wishes]

The GNG has the green and blue reversed, after you swap the green and blue cables on the phase and hall wires, you can run the motor on other controllers like Lyens. Hope that helps!

Thanks Bee. My Lyen controler is on its way actually, i should get it this week, it will solve all my problems. But I'm just itching to try it with higher voltage than the stock controller will allow and I happen to have a controller from em3ev, and I know which are the A B or C wires on the controller. But I can't seem to find the right combination with the motor.

Wishes

 

[bumper]

Sorry if this is the wrong thread to post at but GNG has a "version 3" motor for sale on ebay and their site. Does anyone know what the improvements are over the previous version(s)? I looked at their forum and there is very sparse activity so I thought I'd ask here.

 

[skyungjae]

Sorry if this is the wrong thread to post at but GNG has a "version 3" motor for sale on ebay and their site. Does anyone know what the improvements are over the previous version(s)? I looked at their forum and there is very sparse activity so I thought I'd ask here.

A link to their site would be helpful. :wink: