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

[k-harvey]

the motor on GNG looks similar to e Zip 450w which i used as a crank drive till i came accross cyclone , real jerry built welded freewheel to crank had to peddal when motor going etc .. well eventualy it used to get so hot you could have fried an egg on it. Eventualy bad smell & no go . But it had brushes & the controller that I eventualy got for it was for a winch.The heat would be a good indicator as to how well she'l last.

 

[Cyclebutt]

@ snellmin: I'm going to avoid using a left side throttle for now, want to offer eBike kit installation services, gotta stay with midstream, ergonomics. Good to know that option is available, wasn't aware. Thanks!
@ wavezz2k: Tried that with the throttle position, my up-shift lever hits the twist-throttle housing when mounted in what would normally be the ideal position, possibly a different trigger shifter or a thumb index would work better.

Don't laugh too hard, LoL- found the 8spd hub was stuck because underside GNG throttle ring was in the way (even with rotating 'up') - truly, DOH! moment.

Twist shifters, reference 3,7,8, & 9 spd options -
http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=SRAM+twist+shift

Prefer to have a reverse throw shifter mounted left side, than a left handed throttle, IMHO.
There are several SRAM twist shifters that can swap out for the push button fire. I found a direct swap out for mine for $10, ordered.
Rather than move throttle to the left gonna move the twist shift to the left (just me, can't do left throttle, too many motorcycle hours).

Plus up, add the three speed Lymen function on a thumb switch on the right. Layout is then 8-spd left twist, 3spd right thumb slide, w/ throttle twist on the right in the correct orientation. Waiting now for 80v Lyen 6FET sensorless, couple more batteries to up -volt...

With Lymen 3 spd, even an old school 3 speed itnernal hub would give a 9 spd type setup. Likely work great.. maybe try to find a old schwinn beach cruiser with a 3 spd, that'd be retro.

Although I'm not a big fan of Twist shifters, I like this approach, good idea. My front brake is on the right, due to motorcycle riding so yes, it just feels right to have throttle and front brake (IMHO) together, on the right.

CHAIN DROP:

I've concluded chain drop (inside chain ring) is caused, at least in part, to the abrupt throttle response of this system. Any side-to-side chain slap, combined with the abrupt surge of power can catch the chain (top of the chain ring) at angle and cause chain drop. My home-made chain guide, outside plate, broke while in a sweeping turn during a shift. I never had issues with the chain derailing on the outside before. After that, I made a point of engaging pedal power (puts chain under tension in a normal cycling manor) before twisting the throttle. I'll road test this theory for the next 100 miles or so.

Question: Is the abrupt throttle response due to the controller or the twist throttle. Anybody? THIS is the first problem on this kit, I want to cure.

 

[Cyclebutt]

Do these belts fail under normal power levels?

No belt issues after 75 miles. Running stock, have chain drop and abrupt throttle response issues from new. I'm testing for the long run, 48volt bone stock system.

 

[snellemin]

That abrupt throttle is due to all those freewheels in the drive line. There is a total of 3 freewheels, so it will take a bit to engage at times. But if you control the throttle a bit more, you won't get that power surge. It's different riding this BB setup vs the DD setup.

 

[caijunze]

caijunze: are you using the smaller belt to get around having to use the belt tensioner, or did you just forget to attach your tensioner?

I still dont understand by what u meant "forget to attach your tensioner" ? ^^

here is my picture above i used spring to make more precisely to catch the chain , that can prevent it losen

BTW is GNG controller's Fet can be change by using the Ifrb4110 ?

 

[Rassy]

Question: Is the abrupt throttle response due to the controller or the twist throttle. Anybody? THIS is the first problem on this kit, I want to cure.

Like others, I found the abrupt throttle response hard to use. My solution was to add a small tab (actually just a large accessory band) on the thumb end of the full twist throttle. Now it's easy to control the throttle using my thumb on the tab instead of only gripping the full twist.

I still don't know why the throttle is so touchy. Is it the throttle, the controller, or because of the high RPM motor (compared to hub motors)?

As far as chain skipping or coming off, I've only had one incident, and that was when the GNG tensioner loosened. I think I bumped against something when backing up the bike in the garage. I'm not using the spring. The bicycle chain has been fine in all 7 gears.

 

[neptronix]

Question: Is the abrupt throttle response due to the controller or the twist throttle. Anybody? THIS is the first problem on this kit, I want to cure.

Are you using the stock controller? if so, it likely has problems with such a high-rpm motor.
Does the throttle response basically feel like an on-off switch? IE, there are just a few degrees of power modulation, if any at all?

Because that is the kind of problem i had running EB2 infineon controllers on my MAC motor ( same prob with the BMC motors ), which as you know, is a high RPM motor as well due to it running at 5x the wheel speed.
But this does not just affect infineon controllers. Some non-infineons suffer of it, some do not.

The cure was a new cell_man controller with an EB3 board ( all 9-18FET cell_man controllers past mid 2011 are EB3 ), or a 'mark III' lyen controller. These controllers can be buttery smooth with those hi-rpm motors.

The only thing that can help a stuttery/jolty kinda controller is to lower the amps. That's all you can do.

Sucks that they sell a controller that basically dumps out hard spikes of torque. That's what was ailing BMC/MAC motors for a very long time ( resulting in more wear on the clutch and gears )

 

[bzhwindtalker]

The super fast throttle response is what makes this kit good for me. I can do the same kind of riding with 1/2-1/3 of the power I needed with my previous bikes due to that. It sucks for comuting but is really nice for trials and offroad.

 

[neptronix]

I believe you are talking about the power of the motor - not the ability to smoothly modulate the power itself, to avoid putting big sudden shocks of power on all those freewheels, the chain, and the belt.

 

[bzhwindtalker]

No I am talking about the throtle response and motor acceleration time. Motor power has little to do with that. Being able to put sudden and brutal accelerations can get you out of bad situations offroad. But yeah it kills the drive components way quicker and is a bit dangerous for beginers.

 

[neptronix]

High power is not a problem - it is a sudden shock/torque spike that is the problem that really hurts the components more than anything else. Power should be a bit gradual, rather than 100% all at once within a millisecond.

If you are suffering the same EB2 controller issue i mentioned, it will be hard to modulate the power from a stall, and the throttle range will effectively be on/off. Also, if you just barely hit the throttle from a stall, there's no way to gradually bring the power on - the throttle is more like an on/off switch.

If this describes your experience with the GNG kit, then an EB3 controller would likely help a lot.

 

[parajared]

I experienced abrupt throttle jolts as well, but quickly and easily solved this problem with lyen 3 way toggle switch (http://www.lyen.com). I have three modes:
1) wife mode
2) normal
3) beastly (or the way y'all are driving yours!)

I do most of my riding in mode 2 even in challenging off-road situations. It's better to have a "soft zone" on the throttle than have all that power hit you at once.

 

[Cyclebutt]

Question: Is the abrupt throttle response due to the controller or the twist throttle. Anybody? THIS is the first problem on this kit, I want to cure.

Are you using the stock controller? if so, it likely has problems with such a high-rpm motor.
Does the throttle response basically feel like an on-off switch? IE, there are just a few degrees of power modulation, if any at all?

The cure was a new cell_man controller with an EB3 board ( all 9-18FET cell_man controllers past mid 2011 are EB3 ), or a 'mark III' lyen controller. These controllers can be buttery smooth with those hi-rpm motors.

The only thing that can help a stuttery/jolty kinda controller is to lower the amps. That's all you can do.

I suspected controller issues, there is a bit of a lag between twisting the throttle and "power-on" as well, makes precision maneuvers through trees interesting.

What about the throttle? Anybody found a twist throttle with a better feel for this type of motor? Looking for a low cost fix for the moment.

 

[Cyclebutt]

caijunze: are you using the smaller belt to get around having to use the belt tensioner, or did you just forget to attach your tensioner?

I still dont understand by what u meant "forget to attach your tensioner" ? ^^

here is my picture above i used spring to make more precisely to catch the chain , that can prevent it losen

BTW is GNG controller's Fet can be change by using the Ifrb4110 ?

View attachment 1

Did you have to grind down the end of your bottom bracket tube to install that chain guide? I've seen those guides before and they all have BB mount plates, however, the GNG kit itself takes up a bit of that 68mm space. What kind of modifications did you have to make to fit this chain guide. It looks VERY effective by design.

 

[bzhwindtalker]

New video of stock GNG action :
[youtube]4gNs5abyxFg[/youtube]

 

[exco]

I also had this motor in my ebay watchlist for the last few months and 3 days ago I decided to check here if there were any infos on the motor.
So now it took me three days to read through this thread and last night I ordered mine (450W, 48V).

I will try it out as it is (after checking every screw and adding some Loctite).

Since I want to have sensitive control over acceleration - what is the controller I should be looking at (that can handle up to 72V preferrably)?
Which Kelly Controller?

Also regarding the 72V any opinions on switching from belt to chain, wider belt or custom belt tensioner?

Any suggestions regarding changing the reduction and chainwheel for pedal assist at ~40km/h?

 

[wavezz2k]

Great free ride video, btw. very nice

neptronix wrote:
Cyclebutt wrote:Question: Is the abrupt throttle response due to the controller or the twist throttle. Anybody? THIS is the first problem on this kit, I want to cure.
Are you using the stock controller? if so, it likely has problems with such a high-rpm motor.
Does the throttle response basically feel like an on-off switch? IE, there are just a few degrees of power modulation, if any at all?
The cure was a new cell_man controller with an EB3 board ( all 9-18FET cell_man controllers past mid 2011 are EB3 ), or a 'mark III' lyen controller. These controllers can be buttery smooth with those hi-rpm motors. The only thing that can help a stuttery/jolty kinda controller is to lower the amps. That's all you can do. I suspected controller issues, there is a bit of a lag between twisting the throttle and "power-on" as well, makes precision maneuvers through trees interesting.

THROTTLE response - Cyclebutt Your throttle twist hall sounds bad to me.
I tried a three different hall twist throttles and found the response with stock GNG 48v controller to be identical with two GNG twists, but was notably smoother with a different (better?, different gain profile) quality thumb controller. So it may not be your controller, suggest an easy and inexpensive swap to use another hall throttle, first, before swapping controller. I also, had a faulty GNG controller, that would stutter badly. My 2nd & 3rd work fine, and are quite smooth (you can see those bench tests, it's pretty clear power rolls on reasonably). I agree the stock GNG twist rolls on power fast, but frankly it works fine for me, so either our threshold is very different, or something is up with your 'sticky' power. One source of throttles..
http://www.electricscooterparts.com/throttlesstandard.html#twisthrottle (several for $20, I'd offer to loan you a spare, but with shipping, likely $10, perhaps buying a 2nd makes more sense.)

CONTROLLER Snellimen's Lyen
The Lyen controller sensorless with 3 switch, works well for Snellimen - I'm looking fwd to new test rides . Lyen stated he can program the mini-monster 6fet to over 80v., as my revised LFP pack setup (82v), but it wasn't clear to me how reliable at higher volts, as it's intended for 72v. ..
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=44701

good luck with the throttle fix..

 

[neptronix]

I tried many different throttles. On that same controller that was causing said issues, if i hooked it up to a DD, it was buttery smooth to control - but as soon as you put the MAC motor on, it went back to the same behavior.

Meanwhile everyone was telling me that it was every problem other than the controller.

That's why i mention the controller first

Great free ride video, btw. very nice

neptronix wrote:
Cyclebutt wrote:Question: Is the abrupt throttle response due to the controller or the twist throttle. Anybody? THIS is the first problem on this kit, I want to cure.
Are you using the stock controller? if so, it likely has problems with such a high-rpm motor.
Does the throttle response basically feel like an on-off switch? IE, there are just a few degrees of power modulation, if any at all?
The cure was a new cell_man controller with an EB3 board ( all 9-18FET cell_man controllers past mid 2011 are EB3 ), or a 'mark III' lyen controller. These controllers can be buttery smooth with those hi-rpm motors. The only thing that can help a stuttery/jolty kinda controller is to lower the amps. That's all you can do. I suspected controller issues, there is a bit of a lag between twisting the throttle and "power-on" as well, makes precision maneuvers through trees interesting.

THROTTLE response
I tried a three different hall twist throttles and found the response with stock GNG controller to be identical with two GNG twists, but was notably smoother with a different better quality thumb controller. So it may not be your controller, it's an easy and inexpensive swap to use another hall throttle, first, before swapping controller. I also, had a faulty GNG controller, that would stutter badly. My 2nd & 3rd work fine. I agree the stock GNG twist rolls on power fast, but frankly it works fine for me, so either our threshold is different, or something might be up with your 'sticky' power.

CONTROLLER Snellimen's Lyen
The Lyen controller sensorless with 3 switch, seems to be working well for Snellimen - I'll post my opinion after test rides also. Lyen stated he can program the mini-monster 6fet to over 80v., as my revised LFP pack setup (82v), but it wasn't clear to me how reliable at higher volts, as it's intended for 72v. I..
http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=44701

 

[epack]

Noobie here. Been watching this forum for a while in anticipation of doing my first build. I have no charger or anything.
I've read lots of threads and really respect everyone's experience and would love your opinion.
My goal is maximum speed/power possible in my budget of U.S. $1,500 (give or take a couple hundred bucks) for the conversion kit (bike is Mongoose MTB hard tail)
If I buy the GNG 450W brushless and have $1000 left (+/- a couple hundred), how and what would you spend it on? I'm starting from scratch. I'm pretty set on getting LiFePo4 (for long term battery cycles.)
I'd rather get hi speed/power and shorter distances (like 2 miles) for now and I will parallel in the future if I want distance (20 mile future range). I have some awesome Utah mtns in my backyard with 100's of miles of riding out my backdoor. Some of it is quite steep and long. So I need a mid mount in order to get the cassette gearing options. Also, I'm considering the GNG 900w twin motor mid mount. Seems simpler and might last better in lots of off-road dust/mud/ conditions considering there's no belt to it.
Thanks in advance for anybody's response. Hope you have fun thinking of riding some incredible scenery while you post a reply. When I'm done building it, I'll post some video of some Moab Slickrock riding next time I'm down that way.
I'm hoping there's a few other noobs that are wondering the same thing and by the time they get to this point in this thread, they will appreciate the expertise shared from you.

 

[kfong]

I would go single brushless over the dual brush drives. Throw out the belt and go with a #25 chain. I'm still not sold on the setup though. Motor mount just looks too weak to me.

 

[spinningmagnets]

The biggest reason to go to two motors (on builds in the past) has been to add more copper mass compared to the loads applied to the system. The measure of whether to add a second motor or not, has been if the best available motor is getting too hot under your hardest use.

Brushed motors operate within a narrow voltage range. Brushless motors have more expensive controllers, but they can operate in a wider range, for example from 24V-100V. Having that flexibility can be useful. Swapping to higher volts can sometimes mean that you can use fewer amps to get the same job done. Less amps means less heat in the motor and controller. So far, the stock motor has been proven to run well on 25-amps and 36V-72V.

At 48V-72V the motor is spinning too fast to add pedaling, and the extra power requires upgrading the belt-tensioning on the first stage reduction. But...power-wise, the 72V / 25A motor is 1800W, and the posted performance has been pretty good.

If you want the two-motor kit, I'm not saying don't buy it, I'm just saying be clear on why you want it, and proceed with open eyes. The metal-gear reductions will be loud, and the single-motor 450W kit has been verified to run fairly quiet. I don't know where the breaking-point between one and two motors is, but if you felt you needed 40A for extended time (long and steep uphills?) then using two motors might be worth the extra weight/hassle.

 

[wavezz2k]

Hey Spinning, great thread. -
At 48V-72V the motor is spinning too fast to add pedaling, and the extra power requires upgrading the belt-tensioning on the first stage reduction. But...power-wise, the 72V / 25A motor is 1800W, and the posted performance has been pretty good.

Well stated ..
the 'high' end with a bit too high of a cadence, doesn't happen often on my routine jaunts mostly off pavement. Road bike use with lot's of high speed, could be more of a nuisance not being able to keep up. Not sure where most folks are 'from' experience wise, but 1kw peak of the stock system is a nice ride for single track; Christerljung video of 72v upgrades at 30a ( shown 2kw+ peak, right?), is likely even better for those short power burst. Points on the dual brushed motor, seems like a non starter to me. Certainly, glad I didn't order that one, as hadn't seen any threads on GNG motors prior to ordering.. My earlier (&very limited) experience was a Rayos/Synergy with 24v volt lead pack (cheesy & heavy but worked well for short ride to JPL Lab from Alta Dena) - 'off the shelf' are pathetic compared to many these E.S.custom builds. Again, depends on one's goal (not to replace a 400cc DRZ or build a Zero). The GNG, being light enough to 'grunt' back on a bike rack, is well balanced weight vs power, (IMHO, fun). Now my 8spd hub is working correctly, it gives a solid low end torque, and adequate top-end @48v for dirt roads which is fast enough.

Agree the pipe clamp to the downtube has to be firm to prevent the GNG assembly to torque rotate - adding a tad epoxy putty & fiberglass can help to make a 'saddle', plus getting the band truly tight is important, but mine shows no torque issue at stock power & find the stock mount frame to be fine. I think pipe clamp standoff bracket could be shorter for a stiffer mount, and would move the motor closer to the downtube. Also agreed, Christer's torque strut & idler mod above 70v looks like great & simple mods for 2kw power level. GNG setup is a hoot, with dogs running behind, rather than out in front.

BTW - has anyone figured how to get the small belt pulley off yet ??

Here's photo of the motor leads rotated 'up', some motors had it 'down'. Also, you can see the fiberglass and epoxy putty 'saddle' to stiffen the mount at the the band clamp & reduce bracket (& drive) from rotating.

 

[epack]

Awesome feedback. Especially about the twin motors. What would you choose for batteries, charger, analyst/bms, etc? Remember the budget though. I need a good upfront battery now and would rather get good components now and then spend more on parallel batteries later after its up and running. With that in mind, what charger, etc would you get upfront anticipating future battery needs.

 

[ebiker1]

i'm a newbie too, but i just thought i'd mention there is a pack of A123's for sale in the used stuff. almost bought it myself but the money situation is bleak so i backed off. you might check it out. it is a 100 cell pack with 270 cycles already done.

 

[bzhwindtalker]

Broke my 2gnd belt. this one had maybe 4 hours of riding Time to do some research for a chain drive...
Would a single #25chain do the trick if I go 12-68t? I don't really think it could handle the power for long either :?