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

[Wishes]

thx Wishes!

How high of a driver sprocket would be too high when trying to increase top end yet still have somewhat climbing ability?
The stock gng comes with 12T, but ACS has up to 18T, maybe higher as I didn't check past 18T
I think it would be a simple solution to increase top speed (which is what Im focused on more than off roading)

If you are referring to the stock gng with the chain as the primary, you cannot increase that driver much more than it is. There is no room between it and the large sprocket. They practically touch. Also there is the issue with the actual sprockets themselves. The one GNG supplies is cheap and very thin. Most replacement #219 sprockets that had more than 12T are built too wide to fit the small motor shaft. I know I bought a 14T that didn't fit. Out of frustration, I ended up replacing both stock #219 chain and sprocket on the primary with #25 chain and sprockets. Which provided me with more teeth options.

Now I removed the #25 primary and I'm running LR's belt. And that comes with only 1 driver option for the moment.

Wishes

Oh it didn't fit?? did you use the adapter needed? I think there is an adapter that goes on the inside of the ACS crossfire sprocket.
Maybe you need this in order for it to fit

My mistake you are referring to the secondary, i was talking about the primary. I run the 14T ACS crossfire on the secondary. I don't know what is the largest you can get away with on that side.

Wishes

 

[ebike11]

my fault, shoulda been more clear

 

[spinningmagnets]

Most people try to make the secondary freewheel driver as small as possible, that is why GNG uses a 12T. When it breaks, the common upgrade is the 13T ACS-Crossfire, because the ACS is fairly strong, but that is the smallest one they make. The 13T-15T uses the 3.0mm X 1.0 thread, and that is the thread of the shaft adapter found in this post below.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=42785&p=748459#p748459

 

[ebike11]

Most people try to make the secondary freewheel driver as small as possible, that is why GNG uses a 12T. When it breaks, the common upgrade is the 13T ACS-Crossfire, because the ACS is fairly strong, but that is the smallest one they make. The 13T-15T uses the 3.0mm X 1.0 thread, and that is the thread of the shaft adapter found in this post below.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=42785&p=748459#p748459

I see, but if most are keeping it as small as possible, then wouldn't they be losing out of extra top end??? For under $20 they could go with a larger sprocket and still have torque down low???

Also, and ACS OVER 15T DOES NOT have 3.0mm X 1.0 thread??

 

[skyungjae]

Most people try to make the secondary freewheel driver as small as possible, that is why GNG uses a 12T. When it breaks, the common upgrade is the 13T ACS-Crossfire, because the ACS is fairly strong, but that is the smallest one they make. The 13T-15T uses the 3.0mm X 1.0 thread, and that is the thread of the shaft adapter found in this post below.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=42785&p=748459#p748459

I see, but if most are keeping it as small as possible, then wouldn't they be losing out of extra top end??? For under $20 they could go with a larger sprocket and still have torque down low???

Also, and ACS OVER 15T DOES NOT have 3.0mm X 1.0 thread??

I think it has to do with the pedal cadence more than the actual overall speed/performance of the bike.

 

[spinningmagnets]

Also, and ACS OVER 15T DOES NOT have 3.0mm X 1.0 thread?

The freewheels that have a tooth-count from 16T-22T (or more) typically have an internal-diameter thread of 1.375 X 24 TPI. I don't know of anyone who makes a shaft adapter from the 11mm ID on the GNG jackshaft to the larger freewheel thread 1.375 X 24-inch...

 

[Wishes]

Most people try to make the secondary freewheel driver as small as possible, that is why GNG uses a 12T. When it breaks, the common upgrade is the 13T ACS-Crossfire, because the ACS is fairly strong, but that is the smallest one they make. The 13T-15T uses the 3.0mm X 1.0 thread, and that is the thread of the shaft adapter found in this post below.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=42785&p=748459#p748459

I see, but if most are keeping it as small as possible, then wouldn't they be losing out of extra top end??? For under $20 they could go with a larger sprocket and still have torque down low???

Also, and ACS OVER 15T DOES NOT have 3.0mm X 1.0 thread??

For a lot of people using this kit, the top end you can achieve with it more than sufficient. And as skyungjae also stated, it messes with pedal cadence, which is also important to many ebikers.

Wishes

 

[ebike11]

OK guys thx!

 

[ebike11]

Down at the bottom of this page in the comments, someone suggested using a BMX half link
and that it quiets it down a bit.
http://www.electricbike.com/gng/

I assume he pu.t it on the GNG chain

You guys think it could work well? Would it compromise chain strengh?

Thanks!!

 

[t0me]

I didn't find the comment you're referring to but some of us have changed the secondary reduction chain to a half link one in order to do away with (or reduce the need for) the chain tensioner.
It can help even if you do intend to use LR's bottom bracket set, but especially if you have a 1.0 GNG set or don't have LR's bottom brackets (or have a frame that means you can't use them etc etc).

 

[ebike11]

Oh the comments are at the very bottom, thats where I saw it. 7th down I beileve

 

[Wishes]

Oh the comments are at the very bottom, thats where I saw it. 7th down I beileve

The chain tensioners on both primary and secondary drive cause a lot of noise. By using a half link, you can set your chain length so that you do not need the tensioners. At least on the secondary. Without a half link, your chain is a tad too short or a tad too long.

So the noise reduction they are referring too, is simply the removal of the tensioners.

Wishes

 

[ebike11]

Oh the comments are at the very bottom, thats where I saw it. 7th down I beileve

The chain tensioners on both primary and secondary drive cause a lot of noise. By using a half link, you can set your chain length so that you do not need the tensioners. At least on the secondary. Without a half link, your chain is a tad too short or a tad too long.

So the noise reduction they are referring too, is simply the removal of the tensioners.

Wishes

I got it. I think Ill be ordering the #219 chain from Lightning Rod,
can that chain be used with a half link as well?

Thanks again

 

[Wishes]

Oh the comments are at the very bottom, thats where I saw it. 7th down I beileve

The chain tensioners on both primary and secondary drive cause a lot of noise. By using a half link, you can set your chain length so that you do not need the tensioners. At least on the secondary. Without a half link, your chain is a tad too short or a tad too long.

So the noise reduction they are referring too, is simply the removal of the tensioners.

Wishes

I got it. I think Ill be ordering the #219 chain from Lightning Rod,
can that chain be used with a half link as well?

Thanks again

I've never heard of half links for #219 chains. But with LR's upper brackets you don't need a half link, you can adjust your length accordingly.

 

[bee]

i can't see a front derailleur in your pics. I use one on every bike as chain catch...even if single speed. Never lost a chain recently.. even at several kilowatts... Only way i loose my chains is by shifting under load by accident... then they disaggregate easily.

I don't need one, I run single speed with a totally straight chain line which has eliminated all the chain dropping at the front. I get chain drops now at the rear when jumping because this stretches the chain out a lot, I think it's flexing the chain tensioner. I guess I'll have to try and capture a video of it to figure out what's going on.

 

[LightningRods]

Also, and ACS OVER 15T DOES NOT have 3.0mm X 1.0 thread?

The freewheels that have a tooth-count from 16T-22T (or more) typically have an internal-diameter thread of 1.375 X 24 TPI. I don't know of anyone who makes a shaft adapter from the 11mm ID on the GNG jackshaft to the larger freewheel thread 1.375 X 24-inch...

I don't know of an 11mm to 1.375 x 24 adapter either. I did have 12mm to 1.375 x 24 adapters made and I'm now making jackshaft spindles that are 12mm for their entire length. They're also good quality American steel and hardened. So you could use my 12mm adapter with that spindle and run a 16T or more freewheel on the secondary if that's what you want to do.

 

[AZPaul]

Well I finally got my batteries in and put everything together in a quick and dirty install. I'm using two 6s 8ah lipos. Totally stock it made just over 1000W with a peak of 22amps and was surprisingly quiet. I put maybe 5 miles on it and decided it was time for more power. I did the shunt mod and added a piece of 14 gauge solid copper wire. Immediately the drivetrain starting creaking and popping which I'm assuming is the belt jumping teeth - couldn't quite tell but it doesn't sound happy. This behavior starts at about 30amps. I couldn't even give it throttle long enought to see what the additional shunt maxed out at. I stayed on it for about 2 seconds and saw 51.9amps but I think it was still climbling. The belt teeth are already looking a little ragged even though I only went around the block once. Looks like a belt upgrade is next unless that popping is something else. Thoughts?

 

[Wishes]

Well I finally got my batteries in and put everything together in a quick and dirty install. I'm using two 6s 8ah lipos. Totally stock it made just over 1000W with a peak of 22amps and was surprisingly quiet. I put maybe 5 miles on it and decided it was time for more power. I did the shunt mod and added a piece of 14 gauge solid copper wire. Immediately the drivetrain starting creaking and popping which I'm assuming is the belt jumping teeth - couldn't quite tell but it doesn't sound happy. This behavior starts at about 30amps. I couldn't even give it throttle long enought to see what the additional shunt maxed out at. I stayed on it for about 2 seconds and saw 51.9amps but I think it was still climbling. The belt teeth are already looking a little ragged even though I only went around the block once. Looks like a belt upgrade is next unless that popping is something else. Thoughts?

14 guage wire is a little nuts, your gonna hit 40 amps + for sure. Most people just add solder to the shunt or use a staple. The stock belt will not hold at 30 amps, after skipping it 5-6 times it will be shot and skip regularly. You will want to put as much tension as humanly possible on the stock belt tensioner, that helps.

Wishes

 

[ferret]

Well I finally got my batteries in and put everything together in a quick and dirty install. I'm using two 6s 8ah lipos. Totally stock it made just over 1000W with a peak of 22amps and was surprisingly quiet. I put maybe 5 miles on it and decided it was time for more power. I did the shunt mod and added a piece of 14 gauge solid copper wire. Immediately the drivetrain starting creaking and popping which I'm assuming is the belt jumping teeth - couldn't quite tell but it doesn't sound happy. This behavior starts at about 30amps. I couldn't even give it throttle long enought to see what the additional shunt maxed out at. I stayed on it for about 2 seconds and saw 51.9amps but I think it was still climbling. The belt teeth are already looking a little ragged even though I only went around the block once. Looks like a belt upgrade is next unless that popping is something else. Thoughts?

AZPaul ,
which bag are you using for the batteries?
Can you post a link?
I'm also using 2X 6s 8Ah packs (Zippy 30C) and looking for a suitable bag.

Thanks,
Avner.

 

[AZPaul]

AZPaul ,
which bag are you using for the batteries?
Can you post a link?
I'm also using 2X 6s 8Ah packs (Zippy 30C) and looking for a suitable bag.

Thanks,
Avner.

It's not a bag, just a battery pack I put together. I stacked the two batteries on top of each other then put aluminum angle iron along the four long edges for protection along with an aluminum plate on the back. I then wrapped all of this in gorilla tape. I bought a roll of velcro and cut the straps to length then laid a piece of flat steel bar over the top (and bottom) and a wrapped more tape around that to hold it all together. It works surprisingly well and is simple to take on and off. I don't know how many more batteries I would trust to this arrangement but 4 would probably be ok as well.

 

[AZPaul]

14 guage wire is a little nuts, your gonna hit 40 amps + for sure. Most people just add solder to the shunt or use a staple. The stock belt will not hold at 30 amps, after skipping it 5-6 times it will be shot and skip regularly. You will want to put as much tension as humanly possible on the stock belt tensioner, that helps.

Wishes

Yeah I saw Denisesewa used a staple and only gained 5 amps. I really wanted to see what 40amps felt like so I wasn't taking any chances Tightening the tensioner may have helped for about 3 seconds but there's no hope for this belt/setup at this power level.

 

[LightningRods]

Tightening the tensioner may have helped for about 3 seconds but there's no hope for this belt/setup at this power level.

This is getting to be an old song for people who have been following this thread for the last couple of years but the stock GNG belt drive (1) Doesn't have a proper tensioner (2) Has the pulleys too close together so that the driver pulley has too few teeth engaged (3) Has too few teeth on the driver pulley trying to get too much reduction and so the driver has too few teeth engaged (4) The driver pulley is badly made and does not have a correct HTD pattern and so does not engage the belt properly (5) HTD is not the best belt pattern available. GT belts have twice the power capacity (6) 15mm is a bit narrow for a motor as powerful as this one.

Belt drives are great but they have to be properly designed and manufactured. There are a lot of ways to screw up a belt drive and GNG found most of them.

 

[ebike11]

Hi all,
I went out and got a KMC half link for the stock GNG chain that uses the chain tensioner.
I thought the idea of the half link was to "possibly" quiet it up a tad, as it would emilinate using the stock tensioner,
however even without the half link install, the chain seems to have a lot of slack.
Would anyone know how this works? Thanks!!

 

[skyungjae]

Hi all,
I went out and got a KMC half link for the stock GNG chain that uses the chain tensioner.
I thought the idea of the half link was to "possibly" quiet it up a tad, as it would emilinate using the stock tensioner,
however even without the half link install, the chain seems to have a lot of slack.
Would anyone know how this works? Thanks!!

Try removing a full link. The reason why I was using a half link is because I originally went from a 12T to 13T freewheel.

 

[ebike11]

Hi all,
I went out and got a KMC half link for the stock GNG chain that uses the chain tensioner.
I thought the idea of the half link was to "possibly" quiet it up a tad, as it would emilinate using the stock tensioner,
however even without the half link install, the chain seems to have a lot of slack.
Would anyone know how this works? Thanks!!

Try removing a full link. The reason why I was using a half link is because I originally went from a 12T to 13T freewheel.

I see. But Ill still be using the stock sprocket for now, so Ill have to remove a link or so.
Is there any specific place to break the GNG chain or not?