GNG Drive Gen2
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melodious
100 kW
Nice use of that motor! For those too curious about it (like I am), here it is...
http://www.blessthisstuff.com/stuff/sports/radical-sports/ktrack-snow-bike-kit/
Couldn't find the website for a purchase though. I don't live in snow country so I really didn't try.
http://www.blessthisstuff.com/stuff/sports/radical-sports/ktrack-snow-bike-kit/
Couldn't find the website for a purchase though. I don't live in snow country so I really didn't try.
dont purchase ktrak
its too hard to pedaling, better fatbike
and by the way ktrak's front ski implementation is bad, better alpineskibikes.com, but ktrak's ski quality is better than alpineskibikes xD
and I better choice country without snow and cold xD
winter is cool, but autumn and spring are crap
its too hard to pedaling, better fatbike
and by the way ktrak's front ski implementation is bad, better alpineskibikes.com, but ktrak's ski quality is better than alpineskibikes xD
and I better choice country without snow and cold xD
winter is cool, but autumn and spring are crap
bzhwindtalker
100 kW
Nice video! I always wanted a mid drive Ktrak bike What do you think of that gen2 GNG? I probably should not buy one as I am putting huge loads on the gears wheeliing like I do but it looks really clean and silent! how long have you been runing those power levels?
What do you think of that gen2 GNG? I probably should not buy one as I am putting huge loads on the gears wheeliing like I do but it looks really clean and silent! how long have you been runing those power levels?Just 20 mins. I will never load so much this motor in future =)
I think 400 watts is enough for mid-drive!
About ktrak, after tests I think it suxx. http://endless-sphere.com/forums/viewtopic.php?f=6&t=46790 - there is 5 times funner snow bike config
I think 400 watts is enough for mid-drive!
About ktrak, after tests I think it suxx. http://endless-sphere.com/forums/viewtopic.php?f=6&t=46790 - there is 5 times funner snow bike config
tomschmidtty
1 µW
- Joined
- Dec 17, 2012
- Messages
- 3
iperov said:
I also installed 36V/350W GNG Gen2 mid-drive without the tensioner. It is tight enough for now.
This was a challenging kit for a newbie like me to jump into as my first e-bike, so I imagine most ppl on this forum won't make the stupid mistakes I made.
Basically, BB/motor alignment is tricky; and with zero installation directions included, there are plenty of teaching moments to be had.
Cyclebutt
100 W
Isn't the whole unit built on a BB framework, automatically aligned? What was the issue with the tensioner, photos?tomschmidtty said:
tomschmidtty
1 µW
- Joined
- Dec 17, 2012
- Messages
- 3
My alignment issue was due to the position of their crank chain-ring being so close to one of the nut/bolts connecting the motor to the BB assembly.
The freewheel crank spun fine while installing, but I think my weight/force while pedaling uphill was enough to wiggle the drive a few millimeters. This jammed the crank, stalled the motor, and then I pedaled thru the jam (which destroyed the thread of the aluminum arm where it threaded into crank).
Yesterday I put on a stronger chain on motor sprocket, filed down the nut/bolt a few millimeters with a grinder, and fixed (hopefully) the arm/crank thread connection using JB-Weld Epoxy. pics show the circle of scratches that the nut left on the chain ring
The freewheel crank spun fine while installing, but I think my weight/force while pedaling uphill was enough to wiggle the drive a few millimeters. This jammed the crank, stalled the motor, and then I pedaled thru the jam (which destroyed the thread of the aluminum arm where it threaded into crank).
Yesterday I put on a stronger chain on motor sprocket, filed down the nut/bolt a few millimeters with a grinder, and fixed (hopefully) the arm/crank thread connection using JB-Weld Epoxy. pics show the circle of scratches that the nut left on the chain ring
Attachments
Cyclebutt
100 W
This sounds like another GNG manufacturing issue. Surely the original design didn't make this clearance error. Crank arm flex is to be expected. I'm not sure I understand about the damage to "the thread of the aluminum arm where it threaded into crank." Did you get any photos of this? Are your repairs/modifications holding up. Best wishes and cheers!tomschmidtty said:
rodgah
10 kW
iperov said:
in this video near the end it sounds like the chain is skipping? is it the ktrak or drive chain or simply the front ski on the ground?
I would love to see a video of it on a harder surface to imitate what it would be like with wheels and no snow. maybe rear facing camera showing you go through the gears like your other video. Does the motor or the controller get hot running on ~1600watts (46v 36a), and is that the stock controller or have you soldered its shunt?
cheers
Rodger
jpo
100 mW
I received and installed a gng gen2 kit a couple days ago.
Early impressions and qualifying statement.
First off I my focus is not high speed and power. I want a bike to go normal to fast bike speed (tops maybe 25 mph), climb hills and carry modest sized loads up those hills and into headwinds. I typically ride another bike with a rustic homemade version of the stokemonkey. I really like the way the original stokemonkey worked but I wanted it to freewheel. So I made one myself.
The gng gen 2 has plenty of power for my riding. It will get me up steep hills and i am comfortable with the top speeds.
The cadence speed is about right but the torque comes on a little strong. It would be nice if the torque could ramp up slowly and peek somewhere around 80. instead it has a lot of torque off the line and tapers off. as it reaches peak.
The quality of construction is low. I would say crap but it does works. The question is how long will it last for. Nothing is quite right. Crank freewheel out of round causing tight spot in chain(but they always are). Idler pulley low quality and easily damaged. Main mount to bottom bracket not exactly square. And like tomschimitty I had to grind down one of the nuts to allow clearance between the inner chain ring and the motor mount bolt. There are no ebrake cutouts included and it does not have an on/off switch. If you get one of these system at minimum add a kill switch for safety or be ready to pull main power supply. Phase wires look to be only 18 gauge. and the metal gears are very loud.
I am hoping the metal gears quiet down after some miles and because I don't plan on running that much juice I may look for replacement composite or nylon gears. that is if it holds up.
More on the positive side. Install is easy and straight forward. They thought the system through and lined everything up ok. I don't have a CA yet but it seems like the stock controller is 20 amp. Way too many amps for 18 gauge wire but it will charge up hills. My rear cog set is 12/34 in the lowest gear it will go up anything you will come across on the road. Depending on your riding style this might even work will on the trail. All in all it a love hate. Love the mid drive performance and low center of gravity but wish the quality was better. That said, the price doesn't demand quality.
Anyone knows where to find quiet cogs to replace the metal ones.
If anyone has any specifics i can answer let me know.
thanks
Early impressions and qualifying statement.
First off I my focus is not high speed and power. I want a bike to go normal to fast bike speed (tops maybe 25 mph), climb hills and carry modest sized loads up those hills and into headwinds. I typically ride another bike with a rustic homemade version of the stokemonkey. I really like the way the original stokemonkey worked but I wanted it to freewheel. So I made one myself.
The gng gen 2 has plenty of power for my riding. It will get me up steep hills and i am comfortable with the top speeds.
The cadence speed is about right but the torque comes on a little strong. It would be nice if the torque could ramp up slowly and peek somewhere around 80. instead it has a lot of torque off the line and tapers off. as it reaches peak.
The quality of construction is low. I would say crap but it does works. The question is how long will it last for. Nothing is quite right. Crank freewheel out of round causing tight spot in chain(but they always are). Idler pulley low quality and easily damaged. Main mount to bottom bracket not exactly square. And like tomschimitty I had to grind down one of the nuts to allow clearance between the inner chain ring and the motor mount bolt. There are no ebrake cutouts included and it does not have an on/off switch. If you get one of these system at minimum add a kill switch for safety or be ready to pull main power supply. Phase wires look to be only 18 gauge. and the metal gears are very loud.
I am hoping the metal gears quiet down after some miles and because I don't plan on running that much juice I may look for replacement composite or nylon gears. that is if it holds up.
More on the positive side. Install is easy and straight forward. They thought the system through and lined everything up ok. I don't have a CA yet but it seems like the stock controller is 20 amp. Way too many amps for 18 gauge wire but it will charge up hills. My rear cog set is 12/34 in the lowest gear it will go up anything you will come across on the road. Depending on your riding style this might even work will on the trail. All in all it a love hate. Love the mid drive performance and low center of gravity but wish the quality was better. That said, the price doesn't demand quality.
Anyone knows where to find quiet cogs to replace the metal ones.
If anyone has any specifics i can answer let me know.
thanks
Cyclebutt
100 W
jpo: Nice review. Keep us posted as you put on the miles. Do you have an odometer? I'm very interested in how well this Gen2 holds up. Thanks!
speedmd
10 MW
Thanks JPO for the updates. Weighing this one against the gen 1 kit and interested in your findings.
cheers
cheers
johnamon
10 W
hi d8veh,
I can see that you've owned a number of different ebike configurations, and perhaps you'd be ideal to answer a couple of questions. I wondered how you rate the Gen2 GNG drive compared to wheel drive systems?
How do you feel about the relative merits? ~I bet it goes up hills well but is your Gen2 faster than a hub motor at the top end, same speed, slower? I like the ability to pull around 30mph, but figure the small motor may not be able to drive at 30mph?
Thanks in advance.
John
I can see that you've owned a number of different ebike configurations, and perhaps you'd be ideal to answer a couple of questions. I wondered how you rate the Gen2 GNG drive compared to wheel drive systems?
How do you feel about the relative merits? ~I bet it goes up hills well but is your Gen2 faster than a hub motor at the top end, same speed, slower? I like the ability to pull around 30mph, but figure the small motor may not be able to drive at 30mph?
Thanks in advance.
John
Tested my Gen2 yesterday and am getting 31.5mph at 2amps hooked up but wheel off ground. So with 31mph no load would prob get 25mph on the road. That is with 44v lipo 12s and an eleven tooth rear sprocket. Would quite like to beef up the shunt a wee bit for a little more power bu8t am worried that the 18awg phase wires may not appreciate any more current~ 50amps phase?
I run a Tonaro Bighit at the same voltage and its gearbox transmission is both nicer and quieter than this chain drive, I think.
I run a Tonaro Bighit at the same voltage and its gearbox transmission is both nicer and quieter than this chain drive, I think.
tomschmidtty
1 µW
- Joined
- Dec 17, 2012
- Messages
- 3
The damage to the crank arm thread = stripped...but it is all fixed and solidly attached now. Everything held up great but it has been freezing cold in Philly so I've only been out with it a few times. Uphill performance is very impressive.
I've ordered a freewheel adapter and 13T sprocket, as well as a speedict; so I should have more performance info soon to post
jpo
100 mW
d8veh
I am now running 48 volts with lyen controller set to roughly 16 amp max. My original test ride used stock 48 volt controller.
Friday I took it for a longer test ride about 20 miles. Rode full throttle with motor spinning at what seemed near optimum for in excess of an hour. The motor did get hot. I don't have a lot of experience with what is too hot but it was well beyond warm.
On the left side of the motor there is a small round cover in the center (where the phase and sensor wires enter motor). It was too hot to hold finger on for more than a few seconds (say plus or minus 7 seconds). In the idiots guide to keeping your air cooled vw alive they used a similar test. Pull out the dip stick when motor is hot hold the end between two fingers too hot to hold too hot to drive. I have no idea what is too hot on and electric motor but did not like the heat. At 16 amps the power level is fine for my use. If I have time I will take the motor apart to see if there is someway to improve heat dissipation and or add small heat sink to the end of the motor. For now I plan on turning amps limit down by 25% to 12 amps. They advertise this as 350/400 watt which is less than 10 amps which seems pretty weak.
For me 16 amps gets the job done. This is a work bike as opposed to sport bike. I would be happy at that power level. Hopefully i can fins a why to cool it off.
Has anyone else notice this hot spot on their motor.
Has anyone taken the thing apart?
thanks
I am now running 48 volts with lyen controller set to roughly 16 amp max. My original test ride used stock 48 volt controller.
Friday I took it for a longer test ride about 20 miles. Rode full throttle with motor spinning at what seemed near optimum for in excess of an hour. The motor did get hot. I don't have a lot of experience with what is too hot but it was well beyond warm.
On the left side of the motor there is a small round cover in the center (where the phase and sensor wires enter motor). It was too hot to hold finger on for more than a few seconds (say plus or minus 7 seconds). In the idiots guide to keeping your air cooled vw alive they used a similar test. Pull out the dip stick when motor is hot hold the end between two fingers too hot to hold too hot to drive. I have no idea what is too hot on and electric motor but did not like the heat. At 16 amps the power level is fine for my use. If I have time I will take the motor apart to see if there is someway to improve heat dissipation and or add small heat sink to the end of the motor. For now I plan on turning amps limit down by 25% to 12 amps. They advertise this as 350/400 watt which is less than 10 amps which seems pretty weak.
For me 16 amps gets the job done. This is a work bike as opposed to sport bike. I would be happy at that power level. Hopefully i can fins a why to cool it off.
Has anyone else notice this hot spot on their motor.
Has anyone taken the thing apart?
thanks
Cyclebutt
100 W
johnamon said:
Well johnamon, I can't answer for d8veh, but I can tell you my rear hub (48v,1000w,15Ahr) is stone reliable, efficient and faster (CA indicates it pulls up to 1600W!) in stock configuration. Gen 1 is almost as fast (48v450w20Ahr pack pulls up to 1200W) but you must gear down for hills at speed. Although Gen 1 is great for trails, but it has belt and final drive chain issues.
Can anyone report a few hundred miles with the stock configuration? Speed, distance, pack drain, reliability? Thanks!
My Gen 1 kit has primary drive issues that make this GEN 2 look interesting.
Unless you have hills over 20%, you can't beat a 500w geared hub-motor. They're more or less maintenance free and go for thousands of miles with no strain on your transmission. I run all bikes at 36v and the hub-motors are faster up relatively steep hills and I find it easier to ride in economy mode with a hub-motor than a crank-drive. To me, for my riding, the main advantage of the GNGs is their ability to give maximum power at any speed, which is handy for racing our lycra clad friends, where a hub-motor will max out at the speed it's wound for, but you pay for it in reduced range. The GNGs are a bit easier to install than a hub-motor. I think that they would be much more desirable if someone came up with a controller with variable PAS - ideally related to torque.johnamon said:
