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

LightningRods said:
. There was enough debate about the drag in the jackshaft bearings that I kept putting off rolling the dice. The compromise I finally worked out was to build a prototype that can have either a quality five bolt freewheel center or a 12mm bore. That way users can have a 22mm wide, 120T pulley with or without freewheel. I need an answer to this question of bearing drag and the only way is to try it.

I can only tell you that I drive my cranks through a jackshaft. You can barley feel the additional drag induced by it. Had to pedal home several time because of a flat battery, it works.

Compared to a Hammerschmidt, it does have the same drag (just my opinion), compared to an internal geared shifter hub it has even less drag. The pedal chain drive has good tension (about 2-3N) I hate jumping chains ;) , still drag is quite low.

What is important: Distance between the JS bearings increases stiffness -> less bending, less drag
-Thick Jackshaft bends less -> less drag
-Stiff mount keeps perfect chain-line-> least drag

If you keep in eye on this (I know you use 0.1" mounts) your drive will induce low drag. BTW it would be great to use a Hammerschmidt, but that's not possible since it lacks of freewheel compatibility :(

EDIT: I was wrong, Hammerschmidt HAS build-in freewheel function! Just tested this!!


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I would be very interested in a complete full kit to address the stock flaws
I am planning to install on my Specialized Demo pro 8
 
usa_electrophile said:
I would be very interested in a complete full kit to address the stock flaws
I am planning to install on my Specialized Demo pro 8

I believe it's one of LigntningRods goals. Most people agree that it doesn't make a whole lot of sense to buy the GNG kit and replace almost everything except the actual motor. :lol:
 
its to do with the feeling of getting some thing to work and that you have helped to get working reliably ,, you dont get the same self satisfaction by just bolting a motor to a bike,

other thing is that the GNG is cheap, and even with the mods to make it reliable its still cheaper than most other kits ,,

there was one make out there that cost around £/$ 1,500 and it had a terrible gearbox and the cost or replacing the gear box was expensive even if you fitted it your self,,

i love the GNG1 because i like tinkering with mechanical things at times
 
For me, I agree. However for a couple of friends I'd love to get into it with me so I've got some trail buddies, a strap on kit that's already had the kinks ironed out of it would definitely be the better bet.

Better brackets, better chainring and BB set, better belt/or chain conversion from new, would be excellent.
 
Yeah all my electrics are personal learning experiences (layman's R&D) and I've now got three A2B Metro chassis's, with one standard always operational as my reliable substitute for car/motorcycle/scooter commuting with cycling injuries or illness or if want to save 15min on the 1hr cycle. Wife has family wagon for her/kids (and me to pick up new bikes with ;)

My GNG is still original new unused, not sure where it sits in 'generations' now but same as lightningrods first one when he came to the thread. They had advertised it at the time as some minor update on the original, so not sure if that's what we consider v1.1 here.

I would like to progress it, but every time I've come back to it hit some tangent, or there's been the cusp of the next development here =P
I now have another bike contender for it (Felt MP cruiser) with Inter7 internal geared hub I would like to use it on.

I also wanted to ask if anyone here has tried the GNG 350W hub motor kit?
 
I fall on both sides really. On one hand, I'd love to see something hassle free out of the box; on the other hand, I really enjoy ironing out the kinks myself.

On a personal level, the GNG has been a great learning experience for me. I've learned a lot about bikes in general as well as e-bike tech. :D

Then there are all those people I know who want to get a GNG, understand the benefits of mid-drive, but want something that just works. The one other person I know personally who's actually built up a bike is more fond of wrenches than me:

http://endless-sphere.com/forums/viewtopic.php?f=3&t=50948

He bypassed all my guess and test and just got the parts that ended up working for me. :lol:
 
My GNG v1.1 worked out of the box and I think the alleged weaknesses are overstated. If you add the GNG and a quality battery to your bike, you're good to go. All of the mods that are being developed are great, but they aren't needed. I read many threads about the GNG before buying and based on that I thought it would need a lot of work/upgrades. That simply is not true. I applaud the hotrodders and tweakers, but the stock GNG kit is very functional.
 
kifukarider said:
My GNG v1.1 worked out of the box and I think the alleged weaknesses are overstated. If you add the GNG and a quality battery to your bike, you're good to go. All of the mods that are being developed are great, but they aren't needed. I read many threads about the GNG before buying and based on that I thought it would need a lot of work/upgrades. That simply is not true. I applaud the hotrodders and tweakers, but the stock GNG kit is very functional.

I'm sure many of the people who've modified their GNG kits still agree with your opinion. :wink:

I agree that, when it's being used at its advertised power level and for commuting, the kit is fine out of the box.

Add jumps, bumps, offroad, etc the BB spindle is prone to bending. I do not feel this is an overstated allegation. I was even warned by other GNG users that the BB spindle would bend the way I ride. It's great that we've already ironed out alternatives for off-roaders. It would be nice if GNG offered a 1.2 package with an ISIS BB and Cranks from the get go.

Add power, or use it at 1000w constantly, belt will need replacing more often. However, used at its advertised power and spiking to peak power does is probably an overstated weakness. I do not think everyone with this kit needs a wider belt or chain drive. Though my set up will hit 1500W, I'm still using the belt system the kit came with. I'm still on the original belt. Last I checked, I'm at around 480 miles. I'm typically always pedaling, and I'll keep the power around the advertised level of 450w (my belt is almost always moving). I do spike it to 1000W+ when I'm going up hills.

As all designs, it can be improved on. Though the kit does work fine for, what I perceive, it's intended uses. The gearing, pedal cadence, and efficiency are very important to people who are considering the kit. It's great that we do have people who are trying to improve the kit in these areas and share it with the community. To some, it's options, to others, it's a necessity. Regardless, it's great to have something so modular that it can fit anyone's riding style and habits. :)
 
For those of you running the stock GNG setup. I found a replacement for the stock Gates PowerGrip belt that the kit originally comes with. The price was comparative to the Gates belts. I picked up a few off amazon and the first Goodyear I put in, so far has lasted for more than 3 times the KM i have been getting with the original Gates Powergrip belts the kit comes included with.

Goodyear Engineered Products 475 5M 15 Hawk Positive Drive Synchronous Belt, 475mm Pitch Length, 3.6 mm Height, 5mm Pitch, 15mm Wide

http://www.amazon.com/gp/product/B004EEPG9I/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1



Hope that helps.
 
Wishes said:
For those of you running the stock GNG setup. I found a replacement for the stock Gates PowerGrip belt that the kit originally comes with. The price was comparative to the Gates belts. I picked up a few off amazon and the first Goodyear I put in, so far has lasted for more than 3 times the KM i have been getting with the original Gates Powergrip belts the kit comes included with.

Goodyear Engineered Products 475 5M 15 Hawk Positive Drive Synchronous Belt, 475mm Pitch Length, 3.6 mm Height, 5mm Pitch, 15mm Wide

http://www.amazon.com/gp/product/B004EEPG9I/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

Hope that helps.

Did your original Gates belt break? If so, after how many KM? I preemptively ordered the same belt after reading the Goodyear belt's impressive spec-sheet. My plan is to put the Goodyear belt on and keep the original as a spare. My original Gates belt is in good condition and looks solid after my estimated 150 miles. I want to have a spare belt though when I attempt the shunt mod.
 
I can tell my experience: with 1500w (52v 35A), and hitting the throttle hard, less than 200km... If you want a longer life, please make some mod on the throttle to make it give you a slower response. THat is the key, at least for me. The problem is not break the belt, is strip the tooths of the belt...

- Fabio
 
fabiograssi said:
I can tell my experience: with 1500w (52v 35A), and hitting the throttle hard, less than 200km... If you want a longer life, please make some mod on the throttle to make it give you a slower response. THat is the key, at least for me. The problem is not break the belt, is strip the tooths of the belt...

- Fabio

I bought the Cycle Analyst v3 which has throttle controls, but I have yet to install it. I've just been easing into the throttle. My current shifter and derailer aren't great, so I get clunk-shifts occasionally which I know are bad for the belt. Are you pulling 35A out of the GNG controller?
 
kifukarider said:
Wishes said:
For those of you running the stock GNG setup. I found a replacement for the stock Gates PowerGrip belt that the kit originally comes with. The price was comparative to the Gates belts. I picked up a few off amazon and the first Goodyear I put in, so far has lasted for more than 3 times the KM i have been getting with the original Gates Powergrip belts the kit comes included with.

Goodyear Engineered Products 475 5M 15 Hawk Positive Drive Synchronous Belt, 475mm Pitch Length, 3.6 mm Height, 5mm Pitch, 15mm Wide

http://www.amazon.com/gp/product/B004EEPG9I/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

Hope that helps.

Did your original Gates belt break? If so, after how many KM? I preemptively ordered the same belt after reading the Goodyear belt's impressive spec-sheet. My plan is to put the Goodyear belt on and keep the original as a spare. My original Gates belt is in good condition and looks solid after my estimated 150 miles. I want to have a spare belt though when I attempt the shunt mod.

The Gates belt last only about 120 km on my setup. But I'm running about 3000 watts through it. It doesn't break, the teeth get stripped of their rubber and then the belt starts to slip. And I'm very careful with torque spikes, or it would last even less. So far the Goodyear belt has lasted about 300km, and I have purposely not been careful with it to see how it holds up. And it has been holding up really well. After 300km I am still am not seeing any wear and tear on it. The Gates belt would start to shred and show signs of wear and tear on the side edges of it after 50 km. So far the Goodyear belt doesn't have a single sign of wear on it after 300 km. Even the edges are not threading like it does on the Gates. I'm very impressed so far.

Wishes



Wishes
 
Rouckie said:
If the teeth get stripped, you're belt is probably not tensioned enough.

No amount of tension can prevent the teeth from stripping at 1500 Watts or above.

Wishes
 
kifukarider said:
fabiograssi said:
I can tell my experience: with 1500w (52v 35A), and hitting the throttle hard, less than 200km... If you want a longer life, please make some mod on the throttle to make it give you a slower response. THat is the key, at least for me. The problem is not break the belt, is strip the tooths of the belt...

- Fabio

I bought the Cycle Analyst v3 which has throttle controls, but I have yet to install it. I've just been easing into the throttle. My current shifter and derailer aren't great, so I get clunk-shifts occasionally which I know are bad for the belt. Are you pulling 35A out of the GNG controller?

fechter put somewhere in the forum (I can't find now on the phone) a simple mod adding a variable resistor to the negative wire of the throttle. Search for it.

- Fabio
 
Wishes said:
For those of you running the stock GNG setup. I found a replacement for the stock Gates PowerGrip belt that the kit originally comes with. The price was comparative to the Gates belts. I picked up a few off amazon and the first Goodyear I put in, so far has lasted for more than 3 times the KM i have been getting with the original Gates Powergrip belts the kit comes included with.

Goodyear Engineered Products 475 5M 15 Hawk Positive Drive Synchronous Belt, 475mm Pitch Length, 3.6 mm Height, 5mm Pitch, 15mm Wide

http://www.amazon.com/gp/product/B004EEPG9I/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1



Hope that helps.



Thanx for that tip. Just ordered two..
My belt skips, unshunted, with LR adjustable sheets.
Will try to make a better belt tensioner near the motor pulley, when i get the new belts.
Read something about LightningRods coming with a drive shaft tensioner, that would be nice..

My ride: http://endless-sphere.com/forums/viewtopic.php?f=28&t=49283&p=728668&hilit=toreddy#p728668
 
TorEddy said:
My belt skips, unshunted, with LR adjustable sheets.
Will try to make a better belt tensioner near the motor pulley, when i get the new belts.
Read something about LightningRods coming with a drive shaft tensioner, that would be nice..

LightningRod's adjustable sheets sound like a downgrade if belt skipping is expected at stock GNG amperage. It's one reason I've held off on getting them. The adjustable sheets look less robust without the stock tensioner. If 100 watts is the cost of the stock tensioner and extra tooth grip, it appears the better solution as is or with moderate controller upgrades. The adjustable sheets may only make sense in the context of a primary chain mod.
 
kifukarider said:
TorEddy said:
My belt skips, unshunted, with LR adjustable sheets.
Will try to make a better belt tensioner near the motor pulley, when i get the new belts.
Read something about LightningRods coming with a drive shaft tensioner, that would be nice..

LightningRod's adjustable sheets sound like a downgrade if belt skipping is expected at stock GNG amperage. It's one reason I've held off on getting them. The adjustable sheets look less robust without the stock tensioner. If 100 watts is the cost of the stock tensioner and extra tooth grip, it appears the better solution as is or with moderate controller upgrades. The adjustable sheets may only make sense in the context of a primary chain mod.

Agreed, if you reduce the amount of teeth, as with LR's plates that remove the tensioner from the main drive, you have to compensate. If not you are guaranteed the belt will skip on the stock setup. You have to compensate with either the chain mod or a larger belt mod. The stock tensioner does suck up about 100 watts, but it also forces an extra tooth or 2 to be used. Makes a difference.

Wishes
 
For all those GNG buyers that received a battered or trashed package check out this chinese air freight handler.This is how it happened. Video by a passenger on the aircraft.

http://www.youtube.com/watch?v=tPzRPga6uDg
 
Wishes said:
kifukarider said:
TorEddy said:
My belt skips, unshunted, with LR adjustable sheets.
Will try to make a better belt tensioner near the motor pulley, when i get the new belts.
Read something about LightningRods coming with a drive shaft tensioner, that would be nice..

LightningRod's adjustable sheets sound like a downgrade if belt skipping is expected at stock GNG amperage. It's one reason I've held off on getting them. The adjustable sheets look less robust without the stock tensioner. If 100 watts is the cost of the stock tensioner and extra tooth grip, it appears the better solution as is or with moderate controller upgrades. The adjustable sheets may only make sense in the context of a primary chain mod.

Agreed, if you reduce the amount of teeth, as with LR's plates that remove the tensioner from the main drive, you have to compensate. If not you are guaranteed the belt will skip on the stock setup. You have to compensate with either the chain mod or a larger belt mod. The stock tensioner does suck up about 100 watts, but it also forces an extra tooth or 2 to be used. Makes a difference.

Wishes
So all this hassle with conversions, tensioner and belt mods was unnecessary :mrgreen:
All needed is the Goodyear belt?
 
Might seem like a silly question, but would stepping up to 20mm or 25mm belt help with the belt skipping issues on the primary drive?

All other things being equal, a larger surface area should help transfer the power?

Just before I do something to mine I thought I would air the thought....

Apologies if this was already mentioned/discussed earlier.
 
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