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

[Craigh85]

I look forward to hearing your results at 18s hopefully it handles the extra power. What current will the controler be limited at?
I'm also running a 9 speed cassette really need to try the bike off road didn't get time tonight unfortunately.

 

[flyingdutchman]

I've been overvolting mine with my infineon for a few weeks. I'm on my third belt. It seems the belt drive is the weak link. Anything over 48-volts and it starts jumping teeth. I've run it successfully at 84volts and 30amps. It's fast but it trashed the belt in a matter of minutes. I've found a local source for the belts and just picked up 4-more. I'm hoping a little more experimenting will find the sweet spot. I've contacted GNG and they supposedly have a chain drive retrofit they are working on....he admitted the belt was to weak. He sent a picture from the website of some guy with sprockets bolted onto the belt drive....looks pretty cheesy. The belt is the only issue I'm having...the motor hasn't gotten notably hot. I rode about 12-miles at 84v20amps with a brand new belt. If I ease into the throttle it seems to hold up better. If I floor it.... the cogs would just strip right off the belt. I'm thinking chain drive but I don't like the cheese GNG is proposing. Any ideas?

 

[redstone02]

I've been overvolting mine with my infineon for a few weeks. I'm on my third belt. It seems the belt drive is the weak link. Anything over 48-volts and it starts jumping teeth. I've run it successfully at 84volts and 30amps. It's fast but it trashed the belt in a matter of minutes. I've found a local source for the belts and just picked up 4-more. I'm hoping a little more experimenting will find the sweet spot. I've contacted GNG and they supposedly have a chain drive retrofit they are working on....he admitted the belt was to weak. He sent a picture from the website of some guy with sprockets bolted onto the belt drive....looks pretty cheesy. The belt is the only issue I'm having...the motor hasn't gotten notably hot. I rode about 12-miles at 84v20amps with a brand new belt. If I ease into the throttle it seems to hold up better. If I floor it.... the cogs would just strip right off the belt. I'm thinking chain drive but I don't like the cheese GNG is proposing. Any ideas?

You modified the idler in any way? Just received my drive this afternoon and have been wondering about the small idler.
Thanks,
Red

 

[bzhwindtalker]

The Chain drive looks like an easy retrofit, with 219 I think it will be possible to acheive more reduction quite easy, and with a extron composite sprocket the noise levels will stay quite low.

 

[Cyclebutt]

@christerlijung, Hi I seen your build thread the bikes looking good. Are you planning to increase the power? I've only had mine on the flat, hope to hit the hills tonight. I see you had the chain jump aswell, how many gears do you have?

My rear cassette is 9 speed, som kind of sram. Derallieur is X-7, maybe they aren´t meant to work together it seem to jump 2 steps everytime i shift?

Anyway i like proportions between pedal cadence and motor rpm. Both in highest and lowest gear. The motor is broad in powerband but seem to fade at higher rpm.
That will probably change tomorrow when the Lyen modded controller is attached. Together with 18S 10ah lipo.

Have you had any issues with chain drop, chain ring? Using a chain guide/keeper by any chance? My initial test with the Wally bike resulted in chainring drop several times.

 

[christerljung]

@Cyclebutt, the chain sits fine after a simple mod with woodblock as chainguide, se buildthread http://endless-sphere.com/forums/viewtopic.php?f=28&t=43413

Today was first testride with overvolting. 18S lipo 5A ~72v
Really brutal compared to original powerdelivery!
And dangerous, wheelies is hard to avoid at lower speeds. Was playing around when the wild horse threw me on the back. Normally this would put a big smile on my face but actually my left knee hurts really bad.
As mentioned above, this unit has power when it get the volts. But something probably will fail, the hole unit seem to twist from the pressure of low speed chain. The Long chain was jumping coggs at higher gears under hard accelleration. Belt probably will fail soon as mentioned by flyingdutchman.
Also: The motor was a little warm after 5minutes medium hard riding on flat road. Max speed 50kph. (was 37kph unmodified).

 

[flyingdutchman]

I've been overvolting mine with my infineon for a few weeks. I'm on my third belt. It seems the belt drive is the weak link. Anything over 48-volts and it starts jumping teeth. I've run it successfully at 84volts and 30amps. It's fast but it trashed the belt in a matter of minutes. I've found a local source for the belts and just picked up 4-more. I'm hoping a little more experimenting will find the sweet spot. I've contacted GNG and they supposedly have a chain drive retrofit they are working on....he admitted the belt was to weak. He sent a picture from the website of some guy with sprockets bolted onto the belt drive....looks pretty cheesy. The belt is the only issue I'm having...the motor hasn't gotten notably hot. I rode about 12-miles at 84v20amps with a brand new belt. If I ease into the throttle it seems to hold up better. If I floor it.... the cogs would just strip right off the belt. I'm thinking chain drive but I don't like the cheese GNG is proposing. Any ideas?

You modified the idler in any way? Just received my drive this afternoon and have been wondering about the small idler.
Thanks,
Red

I did modify the chain side idler. I used a roller I had laying around. The alignment of the whole deal was slightly off. The roller keeps the chain tight but doesn't necessarily provide any alignment. It's about 3/4" wide so the chain has some room to wander. I didn't even try the stock idler set-up...the spring stretched out the first time I tested it.

BTW - the belt on mine is a 457-5m-15. I got it at a local supplier called Motion Industries for around $12 and they had it the next day. The Gates website will direct you to the dealer nearest you. I've seen some pictures of other kits and they don't have an tensioner on the belt. I'm assuming that means not everyone's belt is the same. I'd be interested to know what size fits correctly without the tensioner if anyone knows.

 

[full-throttle]

the belt on mine is a 457-5m-15

You mean 475-5m-15? As in 475mm (95t), 5mm pitch, 15mm width

 

[flyingdutchman]

the belt on mine is a 457-5m-15

You mean 475-5m-15? As in 475mm (95t), 5mm pitch, 15mm width

Yes. Yes. 475-5m-15 or 475mm length - 5mm pitch - 15mm width. NOT 457-5m-15...my bad. Thanks Full-throttle

 

[christerljung]

the belt on mine is a 457-5m-15

You mean 475-5m-15? As in 475mm (95t), 5mm pitch, 15mm width

Yes. Yes. 475-5m-15 or 475mm length - 5mm pitch - 15mm width. NOT 457-5m-15...my bad. Thanks Full-throttle

This is the belt on ebay:
http://www.ebay.com/itm/221012653265?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Maybe the belt-tensioner helps the belt-tooths not beeing ripped of? When the belt goes the longer way around the drive shaft the torque stress is allocated over maybe twice as many tooth than compared to a traditional setup without tensioner?

 

[redstone02]

Total noobie here with a couple of questions:

What is the tool called (and maybe a pert number) for the bottom bracket splined nut? Are there difference sizes? What size comes with the GNG kit?

Thanks,
Red

 

[melodious]

The real world testers are giving some feedback. The general consensus from what little I've followed in this thread is, when the drive is pushed above the set performance level you really risk premature wear on the belt and sprockets. Seems the belt is limiting this from becoming a powerhuas.

Funny, because someone addressed the belt issue early into the thread. :wink:

 

[christerljung]

Total noobie here with a couple of questions:

What is the tool called (and maybe a pert number) for the bottom bracket splined nut? Are there difference sizes? What size comes with the GNG kit?

Thanks,
Red

The GNGkit has a standard nut, same as fitted on almost every mountainbike:
http://www.chainreactioncycles.com/Models.aspx?ModelID=689

 

[redstone02]

Total noobie here with a couple of questions:

What is the tool called (and maybe a pert number) for the bottom bracket splined nut? Are there difference sizes? What size comes with the GNG kit?

Thanks,
Red

The GNGkit has a standard nut, same as fitted on almost every mountainbike:
http://www.chainreactioncycles.com/Models.aspx?ModelID=689

Thanks, it was not in my kit.

 

[evrunna]

Hi all i have joined the bandwagon and ordered and received my GNG Kit. I have just received my kit and it looks like it slightly different than the others posted.. i think it may be one of the new upgrades or redesign the bracket that connects to the BB is now connected higher up on the motor. I have taken some photos so you can compare i will start a build thread soon as i will be installing this for my son on his 24inch MTB.. This will be my 2nd build my first was a 9c hub that i purchased from Heyna running 44v lipo which has been running fine and now its starting to warm up i will be using it a lot more.

Vince

 

[christerljung]

Maybe a solution for ripped belts at higher powerlevel could be a bigger belt drive train?
Something like this:
https://sdp-si.com/eStore/Direct.asp?GroupID=342
Are there any other good sources for possible belt-drivetrains?

 

[Miles]

Maybe a solution for ripped belts at higher powerlevel could be a bigger belt drive train?

The next size up is 8mm pitch, which would make the driven pulley too big. They've tried to get too large a ratio on the first stage. An 18t driver pulley would be better. What's needed is is a reduction in pitch on the second stage, in order to get a greater ratio on that.

 

[full-throttle]

I agree. Plus the freewheel should be on the driven pulley so that the secondary stage driver sprocket is readily available. Something like #35 chain.

 

[Miles]

We need someone to put together a remedial kit for the GNG kit

 

[spinningmagnets]

What's needed is is a reduction in pitch on the second stage

the freewheel should be on the driven pulley

Brilliant! With the freewheel on the large diameter pulley (flanged ENO from sick-bikes? ACS Crossfire?), the secondary reduction can have a small driver that is easily half the circumference as the one the kit now has.

For the adventurous, I'd recommend #219 chain for the secondary, since the larger diameter karting sprockets can be had in a quieter Extron composite material ($20 per chainring change, after you adapt the $50 aluminum spider onto the shaft), small teeth, and with higher tooth-counts than anyone would ever need. I would recommend steel for the #219 small cog. This vendor has #219 chainrings in 72T-92T: http://www.tnrkartsports.com/p-314-219-extron-composite-sprockets.aspx , and a quick Google shows 9T-17T drivers are available in #219.

I'd also switch the left-side hex-socket bolts on the pulley/belt cover to chamfered flush-head...just because.

 

[crossbreak]

I'd recommend #219 chain for the secondary

I just saw that #219 chains have about the same tensile strength as bike chains. That's promising. But it's still a hard way to build a dual freewheel crank, which was already discussed :?

 

[full-throttle]

I'd also switch the left-side hex-socket bolts on the pulley/belt cover to chamfered flush-head

Definitely.

ISCG05 tabs are also a must. Should be relatively easy to do.

Perhaps switch from steel to Al for all the lazer cut bits.

A better bottom bracket and crankset would also be nice. I'd say Truvativ Hammershmidt BB and ISIS cranks. Note the extra space for the support bearing on the drive side :wink:

The steel freewheel adaptor can also be made of Al or better still out of two laser cut ~5mm thick plates bolted together with spacers in between. The inner plate will have the support bearing and the standard 104BCD mount. The outer will have the 5-bolt interface to WI ENO and 6-bolt kart sprocket mount.

Who's going to make one?

 

[wavezz2k]

Recently joined forum, thrilled to find this thread. Not all is good with my GNG drive, perhaps someone can help. Jon @ GNG has been super about good com, and has shipped my replacement spindle, which sure wasn't his fault.
I would, however, gladly pay an extra major 'improved packing' fee, to have my package double boxed, and wrapped solid with strap tape. Cause it's been a big hassle for me.

Post absolutely destroyed the ship box, couple parts lost, oddly, chain ring guard broken, and bits bent up badly. Totally took it apart, replaced bolts, rebent the plates, back together.
Maybe good, or no, don't have it spinning yet. Changed much of the alignments, and lock tight and nylocs everywhere. Which probably should do anyway, otherwise I could see bits falling off on the singletrack.

Still don't have the spindle and bearings for the kit, anyone know is there equivalent stateside somewhere, I'm still waiting for the slow boat from GNG?

Regards the wiring, a bunch of the tags fell off and I'm not certain of the 'Key +' connection. I can't seem to light up the unit on my test bench.

I've tried connecting 'Key' to both + and = source, with a bit of throttle and no go ... Clearly, doing something wrong, but hey, could be the huge smack this hardware took rattled something loose in the controller?
Also what's #6 & #7 ??

Thanks in advance, and great group.

>>>>

GNG Electric wiring
1.)Power cables: big red + big black
2.)Motor cables: big yellow + big green + big blue
3.)Hall cables: small red, small black, small yellow, small green, small blue
4.) Key +Red cable (???)
5.) Throttle: red/black/green
6.) (???) red/black/green
7.) (???) black/brown

 

[Craigh85]

Hi wavezz2k

Welcome to Es. Sorry to hear about the hassle you had with the post, I feel you're pain I recently recieved a package from hobby king that looks like it had been in a swamp then kicked up and down a postal depot. Can you claim against the shipping company?
The wiring looks ok to me, On my kit I just wired the key switch to batt + and its been fine not sure what the spare connectors 6,7 are for try emailing gng .

 

[bzhwindtalker]

Mine shipped today, I hope it will be okay on arrival