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

yeah I guess I'm just being a snob for quality gear... rather use existing components rather than replace with some unknown. Probably I should be more concerned about the freewheel than the bottom bracket... not peddling so much after install anyway :)

Dean
 
you can use a standard bottom bracket, there is still the question of making sure the left side of the bottom bracket cartridge has the flange on it.

As I already wrote, they use a lockring, not a flange on the left side of the BB. With a flange it would either not be possible to lock the BB or the motor in place.
These lockrings were still fairly common on cheap bikes one could buy 10 years ago. I got one at your local bike store. I also had to add a spacer to the BB so that the left side thread still has an excess end.

Edit: Here I have a pic of the lockring and widened BB, my tongxin has a width of 68mm, just like the GNG:
 

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yo FT, send me a pic of the motor when when it arrives.

I think I spotted a box of some old stock currie tech ones at work that look the same, might be able to lend you one to perform a max power test.

No idea how you lend someone something with the intent of them blowing up, but still....

GHETTO STEALTH BIKE FTW
http://www.gngebike.com/apps/photos/photo?photoid=161493141

it's like the poor mans bosch mid drive :mrgreen:
 
Got one! I tested it on a Wally World Next, with psydo down-hill forks. Naturally the bike sucks, but the kit seems good. Riding around the neighborhood was a disappointment (I also have a 48V,1000W rear drive Giant) but riding the trails, washouts and gullies was a blast. With all those freewheels (two with the kit plus the rear of my bike) you just pick whatever lower speed you want to spin your motor through and take on gullies that may have seemed too much of a challenge before. I ran my 15 Ahr Ping LiFePo4 without issue for around an hour. Just about killed the bike, will donate to the local community bike shop. Found an incomplete Cannondale F5 that I'm building (raising money for brakes and a wide range cassette) with this set-up. May continue to "wear" the battery in a day hiker pack. Sure was nice, not having that extra weight ATTACHED to the bike, rides well. My guess is that the bike topped 20mph (street) on the crap bike. With a wide range cassette, the Cannondale should be a nice do-all machine. I'd post photos but I haven't found a way to reduce their file size yet (Windows 7). Anybody?
 
BTW I have a video on FaceBook where you can hear the noise level of this rig. Just key in "Cyclebutt" and you'll find it. cheers!
 
hey cyclebutt, would you be so kind to post the vid here, I don't have a failbook account :x

for resizing images I use IrfanView, I can recommend http://www.irfanview.de/

t3sla wrote:
GHETTO STEALTH BIKE FTW
http://www.gngebike.com/apps/photos/pho ... =161493141
the best of this bike is the piece under the side stand :D :D
 
Thanks for the vid cyclebutt. Here's teh link for others
http://www.facebook.com/photo.php?v=380208048711128
I don't know if you actually need a FB account to view it.

Here's a good close up pic from the FB page too (might need to open in a new window to view on the forum)

412401_379571895441410_885903345_o.jpg


Sounds noisier than a hub but not as bad as a cyclone.
You're in the best position to comment though given you own both. Is that correct ?

How does it comepare otherwise to the 48v1000w kit ? Say on the road or straight line acceleration. I'm surprised you said it only hit around 20mph - they're supposed to do around 30mph arent they ?
 
Woah that was quick - did you get it from feepay or from their site?

Also - size of metal around BB would be good - its very tight my 2001 Craftworks DHR208 - really close to fouling the swingarm.
 
LOL, DOUBTFUL, but MAYBE!
 
Just guessing at the speed, no speedo and the mid drive is now on an unfinished Cannondale F5. It doesn't really compare well for speed, especially compared to the Papamotor 48V, 1000W rig. I've seen 1612 watts register on my CA while under load w/Papa. Won't be able to give stats on the new mid drive until sometime in September, budget and all. All that drive reduction system sucks away power but I still like the versatility of rear gear selection, makes the difference for me.
 
That silver colored motor in the last post with a photo is a brushed 36v 450 watt motor for one of GNG's newer side mounted kits. However I've been wondering if the screw spacing on it is the same as his normal 36v 350 watt motor since I could upgrade to that motor and speed controller along with it if it will fit.

I do not own the brushless kit. I own the 36v 350 watt version that puts the motor under the rear forks (and thereby blocking the kickstand mount) and also drives the main chain instead of having it's own chain spinning the crank's chainwheel like in that brushless kit.

Most of the noise I'm getting is from the gearbox. I suppose the noise won't be anywhere near as bad as mine since it uses a belt drive instead of a gearbox like there other kits.

With my kit the motor drives the same chain the pedals drive. So on first gear I get around 18MPH. I get 24MPH on second gear. There has been one time I was able to hit third gear and that was when I had some wind at my back. I almost hit 30MPH on the thing but ran out of road. :p (topped out at 28MPH). Baring any hills or wind, it will usually get me on second gear. First gear works pretty well and doesn't have problems with anything I've hit thus far. I've gone up the steepest hills I can find in my mostly flat town and haven't had problems.

The brushless kit in this thread however runs at 48v and has a higher watt rating, I assume it will do better then mine if the way everything is geared is an improvement. Right now my only issue is that the motor can have trouble with second gear sometimes if I hit a bit of resistance. My rear freewheel has a 34tooth first gear, but second gear is only 22 teeth so that's a bit too much of a drop from first gear. I found a new freewheel online that has a a 28 tooth second gear and should have a much better transition from first to second. But it's a bit pricey at $44 so I plan to save up before buying that. :p

Aside from the sidemounted kits having weak mounting brackets, the rest of what I got from GNG seems to hold up well for me. I used the same motor and upgraded it to a mid-mounted system since GNG was nice enough to sell the mounting hardware for the mid mounted kit separately so I didn't have to buy a whole second kit just for the mounting hardware. Motor still works fine after putting nearly 600 miles on it thus far. So I'm to assume his other motors will at least perform good at their rated power levels. I haven't dissassembled the motor or anything so I don't know how the motor is built so as for thermal performance....don't know. After a maxing out the battery range at 10 miles on a non stop trip, I felt the motor. It was hot to the touch, but not enough to burn my fingers and it didn't feel like it was hot enough to melt down or anything. I've noticed the heat seemed to be greatest on the rear panel of the motor(where the brushes are I assume). So I'm guessing that is where the motor windings are offloading their heat to the rest of the motor frame. Not to mention the gear box is probably adding some heat to the mix as well.

But I don't have the brushless one so unfortunately I can't say how that one will perform and how well it would work if one would over volt or go beyond it's rated wattage power.
 
Yeah that above pic looks like a crappy old curry - noisy and not much guts. The newer ones posted previously should be a fair improvement.
I suspect full throttle will enlighten us all very shortly :)
 
It's here 8)

heathyoung said:
Woah that was quick - did you get it from feepay or from their site?

Also - size of metal around BB would be good
Got it from their ebay store, paid for whatever the highest shipping there was.

The internal BB width is 67mm, looks like it will stretch to std 68mm no problem. Lazer-cut steel is 2.5mm thick.

The freewheel assembly has an extra support bearing. Nice!
Inner ring (driver) is 38t, outer (driven) is 44t and there's a plastic guard.
Crank arms are sand-blasted and black anodised.
BB is 150mm wide.

The belt is 5mm pitch, 15mm wide. Jack-shaft output freewheel is 12t.
Motor is 120mm dia x 70mm wide.

Will power it up and weight later today.
 
Weights:
Complete motor assembly 4.3kg
Chainring assembly 1kg
BB 400g
Crank arms 530g

No load current with nothing connected @ 48V - 2.3A
No load current with 1st stage and jack shaft @48V - 3.6A
Jack shaft output @ 48V - 570RPM
so with 12/44 2nd stage no-load cadence will be 155RPM
1st stage is 14/80 and the belt is Gates

Anything else just ask
 
This looks extremely interesting, and is what I am trying to achieve with my cyclone.

Perhaps its time to jump-ship from cyclone and try this?
 
Really interested to hear your impressions once this is on the bike, full-throttle.

No-load cadence of 155rpm sounds high. But I guess once it loads up this puts peak power out at more normal cadence.
So 48V x 3.6A = 170w up to the first stage. What is the no-load current including the second stage?
 
155 rpm at the pedals! It almost needs another stage reduction, or a much larger pulley. If you are happy to not pedal along with it, then it is probably ok.

I wonder if you can run it on, say, 24v instead?
 
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