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

[speedmd]

Hi LR

Hows the hunt going for motor makers! It's a jungle out there isn't it. Nice work on the kits. 8mm is extremely strong stuff with lots of options. Logical step for the ones going into moto territory. "Build it and they will come".

cheers

 

[crossbreak]

so t8f and #219 is the same (5/16" or 7.7mm)? I used "real" 8.0mm chains before.. they are weak, #219 are quite strong.. i'd say as strong as a bicycle chain just smaller pitch..

 

[LightningRods]

Hi LR
Hows the hunt going for motor makers! It's a jungle out there isn't it.

Hi SpeedDoc- I'm finally getting some traction on sourcing motors. I'm getting ready to buy 100 from a factory in Shanghai. They sent me a sample and the motor is identical to the GNG other than a 2.5mm wider center case and helical drive gear. As luck would have it the wider case fits in my adjustable 68mm sheets without modification. We're tangled up in the Chinese Spring Holiday right now so I'm holding off until Feb 5th to place my order. No sense in letting them hold my money for two weeks.

so t8f and #219 is the same (5/16" or 7.7mm)? I used "real" 8.0mm chains before.. they are weak, #219 are quite strong.. i'd say as strong as a bicycle chain just smaller pitch..

Hey Crossbreak- No t8f and #219 are not the same. #219 is .30" pitch and t8f is .315" or 8.0mm. Despite being smaller in pitch #219 is stronger chain because of the quality of the metal in the good ones. #219 is even stronger than typical 1/2" bicycle chain. I use Japanese DID 'hard pin' which is even stronger. For the primary side t8f is probably strong enough and an easy bolt on fix for the terrible driver sprocket that the 60v comes with.

 

[speedmd]

Hi Crossbreak

Good point you make. I went back through my spare parts and see I was in fact confusing the two. They are 219 chain / approx 7. 7 (just under .31") going by a more careful measurement. Strong stuff. Do not have that bike for quite some time now and appreciate this getting cleared up in my head. The t8f I don't know at all.

 

[speedmd]

No sense in letting them hold my money for two weeks.

Oh shite! Should have warned you about that. You just gave them permission to delay things a extra month. :lol:

 

[r3volved]

Is the 450w belt kit using the same chain as the 60v primary chain drive?

 

[LightningRods]

Is the 450w belt kit using the same chain as the 60v primary chain drive?

I assume you mean on the secondary side. Yes it's the same 1/2" bicycle chain. The Gen 2 also uses the same BB and chain.

 

[Somebodystopme!!]

So I received my new 13t primary motor and 63t JackShaft sprockets. Look to be an exact fit. cant wait to install them and see what the noise level is.




View attachment 1

 

[LightningRods]

You've lost just a tiny bit of reduction with 13/63 (4.85:1) vs. 11/54 (4.90:1). I think that you made a good decision going with a 13 tooth driver. Combined with the adjustable sheets that you bought which will eliminate the steel idler tensioner you should get a nice noise reduction as well as longer chain life.

I was surprised to see that the replacement sprocket wasn't really any thicker than the GNG 11 tooth. The 8mm sprocket is a lot narrower than a #219 despite despite having a longer pitch.

8mm sprocket next to a 219:

 

[ten.ring]

standard chain tensile strength
25 pitch 875lb
8mm pitch 1136lb
35 pitch 2100

bicycle chain ???
mark

 

[Rollodo]

standard chain tensile strength
25 pitch 875lb
8mm pitch 1136lb
35 pitch 2100

bicycle chain ???
mark

Don't mean to be rude, but is there a question coming up (meaning, consisting of an actual, well-written and constructed statement)? If not, chicken wings with doritos should do just fine.

 

[ten.ring]

if I were a college grad I might be a better writer, but I aint. I simply posted the standard tensile strengths for the chains discussed on this page. I do not know the number for bicycle chain.
sorry for confusing you higher intellect!
mark

 

[LightningRods]

There are lots of types of 1/2" bicycle chain. Not only does it vary by type but by quality. I've read repeatedly that single run BMX chain is the tensile strength champ at 2,000 lbs +. Again based purely on what I've read you can pretty much keep on deducting strength as you increase the number of gears that the chain is supposed to side flex onto. For our purposes we want fewer gears and more strength. As soon as I get two seconds I'm going to look into five speed cassettes and chain for the final drive on my Specialized hardtail. The stock sprockets look like they were stamped from pie tins.

 

[ten.ring]

correct lightningrods.
the tensile strengths I posted are industry standards a mere guide line for manufacturers. all chain sizes vary in strength from quality and material. and the design of the drive line has everything to do with chain life, regardless of chain quality.

rollodo
some write poorly because they are lazy but for me I am just stupid.

 

[LightningRods]

Stupid people want jacked-up 4x4 pickups, not electric bicycles.

Something I say in reference to myself all of the time: "Thank God there's a big difference between ignorant and stupid."

 

[LightningRods]

One of the ideas that I've been playing with is to experiment with the middle three positions of a 5 cog freehub and see if a strong BMX chain would side flex enough to allow derailleur shifting between three cogs. Derailleur chain has to both side flex and twist in order to jump from one cog to another. Strong link chain resists twisting and side flexing and so it's probably not going to shift very well. It's one of those situations where there may be a sweet spot between strength and shiftability. On a bike with more than 2kW we definitely don't need more than three wide ratios.

 

[skyungjae]

One of the ideas that I've been playing with is to experiment with the middle three positions of a 5 cog freehub and see if a strong BMX chain would side flex enough to allow derailleur shifting between three cogs. Derailleur chain has to both side flex and twist in order to jump from one cog to another. Strong link chain resists twisting and side flexing and so it's probably not going to shift very well. It's one of those situations where there may be a sweet spot between strength and shiftability. On a bike with more than 2kW we definitely don't need more than three wide ratios.

I hear you. I've actually been thinking about going with a 7 speed rear cassette. According to Chalo, it does have strength benefits over 8/9/10 speed drivetrains while having available indexed quick shifters.

 

[speedmd]

thinking about going with a 7 speed

I hear this and it sounds plausible but I am not sure it would be actually stronger. The narrow stuff is made with much much better material, has much better heat treatment, much more secure pin end profiles and better designed overall. I would like to see test results before going backwards. Most riders in the day wore out six and seven speed stuff weekly in spring training. The modern stuff out lives that 2 fold minimum. I have personally been left stranded miles into the woods on broken seven speed stuff and never broken a ten speed setup. I hear of guys getting 20000 miles on a ten speed campy cassette changing out chains every 3- 5000 miles in dry conditions lubing regularly. Not even thinkable with the old stuff.

 

[christerljung]

One of the ideas that I've been playing with is to experiment with the middle three positions of a 5 cog freehub and see if a strong BMX chain would side flex enough to allow derailleur shifting between three cogs. Derailleur chain has to both side flex and twist in order to jump from one cog to another. Strong link chain resists twisting and side flexing and so it's probably not going to shift very well. It's one of those situations where there may be a sweet spot between strength and shiftability. On a bike with more than 2kW we definitely don't need more than three wide ratios.

Been thinking about the same. On the GNG 24s >3kw i still havent broken a chain. (shimano HG40) But still, what if i had dual GNG:s... or a bigblock? The BMX halflink is strong but how would a cassette be configured to fit that chain even if it is possible to do derailleur shifting?
And then there is always this sweet point where things starts to be a motocycleproject and not a bicycle...
I want a Yamaha PED1

 

[dan974]

the KTM should be here finaly this year too :

 

[Muapeia]

The police did not forget us, they are preparing to run carrieth of our humble ebikes with these horrible monsters!

 

[LightningRods]

And the Zero FX. I'd like to have an electric motorcycle in addition to my electric bicycle. A different tool for a different job.

I'm looking forward to playing with chain and sprocket some.

 

[Somebodystopme!!]

I discovered yet another issue with the GNG chain Drive And my larger sprockets. The noise level is just as bad so the 13t motor gear did not help there. And now the larger jack shaft Sprocket hits my front tire under hard braking. It wasn't found out with an accident but my 29'ers big from tire flexs the cheap suspension fork too much.

I don't expect to hot rod and over volt this setup. I just want quiet power. With the noise that chain makes I might as well have a gas powered cycle.

That's too bad. Looks like I'm changing gears figuratively speaking. I just bought a bafang BBS02 48v 750w mid drive and will be installing that into my frame.

My belt driven GNG setup has made its home on my 32" beach cruiser. It's acceptably quiet. I'll just have to keep a couple extra belts with me.

I have 2 sets of lighting rods upper sheets and a chain driven GNG 48v 500w setup available. If anyone's interested PM me.

 

[LightningRods]

The noise level is just as bad so the 13t motor gear did not help there.

So even with the steel idler removed and a larger tooth count driver the chain drive was just as loud? People have been saying that #25 chain isn't that bad. Is there something about this 8mm chain that makes it louder?

I was surprised and disappointed to see that the 13 tooth driver you bought was just as thin as the 11 tooth. I measured both the driver and driven on the 60v and the driven was almost twice as thick. There is no reason for the driver to be so thin and cheap except that it's easier to stamp them out. According to Spinningmagnets thin sprockets 'ring' and thicker ones are deader and quieter.

Sorry things didn't work out with the chain drive. I'd better get to work on the belt conversion for the 60v.

 

[Somebodystopme!!]

The noise level is just as bad so the 13t motor gear did not help there.

So even with the steel idler removed and a larger tooth count driver the chain drive was just as loud? People have been saying that #25 chain isn't that bad. Is there something about this 8mm chain that makes it louder?

I was surprised and disappointed to see that the 13 tooth driver you bought was just as thin as the 11 tooth. I measured both the driver and driven on the 60v and the driven was almost twice as thick. There is no reason for the driver to be so thin and cheap except that it's easier to stamp them out. According to Spinningmagnets thin sprockets 'ring' and thicker ones are deader and quieter.

Sorry things didn't work out with the chain drive. I'd better get to work on the belt conversion for the 60v.

The idler noise is gone but I think that 8mm Chain along with the thin sprockets account for the noise. The standard bike chain on the right side is very quiet so it must be the chain and sprockets combo. I'm just tired of throwing money at it trying to quiet it down. I just want about 500 watts of help climbing hills but I want it to be somewhat quiet.

I may be too picky but the chain drive took the joy out of the ride for me.

Your wider belt drive would definitely be the way to go depending on the size of the primary jack-shaft sprocket. (at least for my frame) but I think the BBS02 Bafang will provide what I'm looking for.