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

Great looking bike, Hillyterrain! Thanks again for allowing me use of your sealed jackshaft to design the new 1.1 upper sheets. Everyone who gets a set is in your debt.

I just got a photo from Stoney Fabrication, my machinist in Southern California, of the prototype for the new aluminum billet jackshaft housing.

First_Prototype.jpg


These housings will have a 12mm steel shaft available with both stock GNG style fittings on the end and also custom ends for sprocket conversions and other hijinks. The end lock rings will also be billet aluminum. The plan is for an anodized finish.

If you have a Gen 1.0 and want a sealed jackshaft housing that is far stronger, your stock Gen 1.0 jackshaft should fit. I will be converting my own 1.0 as I build my bike. I'll confirm that the jackshaft fits. Production housings will be available for sale very soon.
 
spinningmagnets, I'd be more than happy to help by providing load data, unless switching gears or trying to give the battery a break the controller pretty much draws 22amps straight for 8 minutes, that's the commute. I hear different things about the hill, everything from 17% to 22% over 1.2 miles, I have two options to go up the hill, I'll see if I can run a terminal on my phone and log the CAV3 data on it and overlay it with the barometric/gps elevation data, if you want to send me that temperature probe I can overlay the temp data, too (should be coming out of the CA in the same data stream?) As a little appetizer here is a first quick elevation profile of one of the commute options:

chart.png

I'm looking at a couple of mod options, my first belt got killed overnight, I have to figure out why, maybe go with a chain, the cadence is way too fast so I have to change the reduction to the crank and more power would be nice so I might do the shunt mod to get 27+ amps from the controller ...

However if it is the controller that overheats too fast, then maybe better not? Which controller would you recommend as a replacement? Lyen / cellman?

I also do high-load jobs like pulling longboarders up hills etc :)
 
I've managed to keep my original belt in rather good condition. However, I do pedal quite a bit (usually pedal before giving any throttle), and about half the 300 miles I've put on it is probably downhill with not too much throttle or load on the belt.

I would love to gun it from a stop, but the belt isn't my only concern as is the entire drivetrain shock. It would be quite amazing if I could put 1000 miles on the original belt. :wink:

Regardless, peace of mind is worth a lot, so I do intend on making some changes whenever they're available.

We'll see how long the belt lasts with my 30A shunt mod. :lol:
 
hillyterrain, I'm sure you can hear a slight bog in the motor RPMs when it is being stressed, I only want to know what gears work for the steepness you have.

Of course you should downshift to a lower top-speed as needed. I would like to know the limits of the stock controller and also the the stock pulleys/sprockets to get a baseline. Of course, if using higher voltage and more reduction, this motor coupled with a Lyen 12-FET is capable of MUCH more than the stock system (12 FETs can take more heat than 9 FETs).

PM me your mail address, and which temp probe you would like from this thread: http://endless-sphere.com/forums/viewtopic.php?f=1&t=25502
 
I'm trying to pm you but just noticed that all my pms get stuck in the outbox for weeks ... maybe if you have more luck with pms you can send me your email address .. ? I think for the CA a 10K NTC thermistor is best ..
 
Hi everyone,

Im new in all this about ebikes. I have been following this forum for a while and finally decided to order a GNG 450 Brushless kit. So I would like to have the opinion of this forum about the set up Im thinking about if you like, any help would be very very helpful!!

I use the bike a lot, and usually do a commute of 10 miles every day. The problems for me is that during my commute I do have some very pronounced hills in the way. I like to use the pedal like a comon bike so thats one of the main reason I have chosen the mid drive system instead of the hub one, bearing in mind that hub systems create some resistance into the pedal while no using the motor, and I want to be abble to pedal like I always do in the flats of my commute with out any additional drag.

So and because I just want the motor for particulary hills, I dont need a lot of autonomy in the batteries. Also im planning on carrying them in my backpack and thats an other reason why Im not interested in comercial batteries for ebikes, they are too heavy and just dont want to carry with 20 pounds in the back every time I get the bike. Also and because I will carry the batteries in the backpack I will go with LiFePo4, just looking for the highest safety.

So... what do you think about three of this from hobbyking?? http://www.hobbyking.com/hobbyking/stor ... _pack.html
The voltage of this Turnigy Lifepo4 battery with 18 cells in series is 59.4V nominal, 64.8V fully charged. Thats why I will also change the controller to an 9 FET 3077 Mark II (Sensored) LYEN Edition Controller. Because of the slope of the hills that I will need to cross and the off-road use I will give to this kit I think I will go over the 22 Ams top cap of the original controller so thats an other good reason for this controller change. Im aware that all this will turn this kit into a 1500W kit and that will give me troubles with the belt, Im counting with that, I guess I will ending changing it for a chain.

But what really concerns me and the reason of this post is that I really dont have any idea about if Im doing it right with this batteris from hobbyking. It is just difficult to find a good configuration using RC batteries if you are not using LiPos, which is my case, also I was looking to use the less number of batteries possible (because the autonomy I need) so I dont want to go with 5x8400mAh LiFePO4 batteries as I have seen some people have done, to much for me I think but I may be wrong... i dont know, what do you all think?!?

If im not mistaken this would be 4500mAhx2 (because the 2P) so 9000mAh, if Im reach 25-30 amps while going up through the high slope hills (I dont know if this number of amps are realistic so im just guessing) that would give me around 15-20 minutes of autonomy at maximum power?? Maybe my calculations are just horrible and a joke for you and im missing some very important facts... but i dont know!

My bike is a dirt Specialized P2 Cromo i will try to attach some pictures!

Thanks for the help and I hope you can understand my english!!
 
Craftair said:
Hi everyone,

Im new in all this about ebikes. I have been following this forum for a while and finally decided to order a GNG 450 Brushless kit. So I would like to have the opinion of this forum about the set up Im thinking about if you like, any help would be very very helpful!!

I use the bike a lot, and usually do a commute of 10 miles every day. The problems for me is that during my commute I do have some very pronounced hills in the way. I like to use the pedal like a comon bike so thats one of the main reason I have chosen the mid drive system instead of the hub one, bearing in mind that hub systems create some resistance into the pedal while no using the motor, and I want to be abble to pedal like I always do in the flats of my commute with out any additional drag.

So and because I just want the motor for particulary hills, I dont need a lot of autonomy in the batteries. Also im planning on carrying them in my backpack and thats an other reason why Im not interested in comercial batteries for ebikes, they are too heavy and just dont want to carry with 20 pounds in the back every time I get the bike. Also and because I will carry the batteries in the backpack I will go with LiFePo4, just looking for the highest safety.

So... what do you think about three of this from hobbyking?? http://www.hobbyking.com/hobbyking/stor ... _pack.html
The voltage of this Turnigy Lifepo4 battery with 18 cells in series is 59.4V nominal, 64.8V fully charged. Thats why I will also change the controller to an 9 FET 3077 Mark II (Sensored) LYEN Edition Controller. Because of the slope of the hills that I will need to cross and the off-road use I will give to this kit I think I will go over the 22 Ams top cap of the original controller so thats an other good reason for this controller change. Im aware that all this will turn this kit into a 1500W kit and that will give me troubles with the belt, Im counting with that, I guess I will ending changing it for a chain.

But what really concerns me and the reason of this post is that I really dont have any idea about if Im doing it right with this batteris from hobbyking. It is just difficult to find a good configuration using RC batteries if you are not using LiPos, which is my case, also I was looking to use the less number of batteries possible (because the autonomy I need) so I dont want to go with 5x8400mAh LiFePO4 batteries as I have seen some people have done, to much for me I think but I may be wrong... i dont know, what do you all think?!?

If im not mistaken this would be 4500mAhx2 (because the 2P) so 9000mAh, if Im reach 25-30 amps while going up through the high slope hills (I dont know if this number of amps are realistic so im just guessing) that would give me around 15-20 minutes of autonomy at maximum power?? Maybe my calculations are just horrible and a joke for you and im missing some very important facts... but i dont know!

My bike is a dirt Specialized P2 Cromo i will try to attach some pictures!

Thanks for the help and I hope you can understand my english!!

It's not necessary to cross post. :wink:

Your link doesn't work. Are these the batteries you're talking about?

http://www.hobbyking.com/hobbyking/store/__10311__Turnigy_4500mAh_6S2P_30C_LiFePo4_Pack.html

If you're trying to go 18s with 9Ah, you're gonna need 6 batteries. That's a lot of battery... unless I'm mistaken about the battery you want to use.
 
Hi skyungjae

You arent mistaken, those are the batteries I was talking about. Ok so I guess I just learned somethink new about this batteries. I just thought that because they where 2P I should multiply by two the total mAh of each battery, so the capacity where the double (I thougt 6S2P meaned that one of this batteries was made of 12 LiFePo4 units in total, two packs in parallel of 6 cell in serial each pack, so thats why I thought the capacity where double) Now I think I understand it, but then i dont understand why someone would want to know the "Ps" of the batteries if you know already the capacity in mAh... ¿? If I have understant you correctly, this two hypotherical baterries: 6S1P 5000mAh 30C and 6S2P 5000mAh 30C in terms of performance are equals??

I have seen that you actually used this kit with five 8400mAh LiFePO4 and said that where thinking about going with 6S lipos. Why did you ended with that conclusión? Lipos looks attractive because with just two 6S you get 48V and 5000mAh wich is reasonable autonomy. But witch LiFePo4 is more difficult because they are bigger i think. Well, considering your experience with LiFePo4 and Lipos and in my position what would you recoment to me considering my request?

Thanks a lot for replying!
 
Craftair said:
I have seen that you actually used this kit with five 8400mAh LiFePO4 and said that where thinking about going with 6S lipos. Why did you ended with that conclusión? Lipos looks attractive because with just two 6S you get 48V and 5000mAh wich is reasonable autonomy. But witch LiFePo4 is more difficult because they are bigger i think. Well, considering your experience with LiFePo4 and Lipos and in my position what would you recoment to me considering my request?

Thanks a lot for replying!
One of the main reason people choose LiFePo4 over LiPo is a concern of safety over function. I personally cannot go the LiPo route since I live in an apartment complex and am not looking forward to getting evicted because one of the packs went rogue and exploded, probably taking the entire set with it, along with other electronics, etc.
 
LightningRods said:
Hi Skyungjae- I've been busy this week. Here's a progress report:

I have five motor spindles on hand which can be machined to the diameter and length the customer chooses. You can also add a square keyway and/or tapped hole in shaft end for retainer bolt. One of these to a customer until I figure out the demand for this part and have enough stocked. PM me if interested.

I'm going to offer TWO drive pulleys for this motor. The first is fully modeled and going to the service bureau for output today. It's an 18 tooth, 20mm wide HTD5 that slips onto the stock GNG pulley. I'll be casting these out of a zinc/aluminum/copper alloy that is stronger and more wear resistant than aluminum. The second pulley is made for the 12mm output shaft. It's an 18 tooth, 25mm wide GT2. This GT2 pulley will have about 2x the power handling capacity of the slip on version and 4x that of the stock GNG. I'll also be casting this one out of zinc alloy.

A 120 tooth, 22mm wide HTD pulley is coming soon. It will have the option of a five bolt pattern freewheel or 12mm bore hub. I'm developing a 95 tooth GT2 with the same freewheel and hub option.

I'm sourcing the materials to make a sealed jackshaft with 12mm spindle. It will fit my upper sheets and make it possible for DIY builders to scratch build their own mid drives. I will be offering jackshaft spindles to fit a variety of off the shelf pulley and sprocket sizes plus offering custom spindles.

I'm designing a screw tensioner for the upper sheets. Some users struggle with the fire drill needed to align and tension the sheets. This tensioner will make it simple.

I've sold all but one set of my new upper sheets for the GNG 1.1. Another run back from the laser shop this Friday, then another week for plating. All of my sheets are sold zinc plated now. The tensioners will be sold separately for both existing owners and new customers.

Finally, I've bought the bike I'm going to do my build on. It's a new 2013 Specialized Hard Rock 29. I also have my batteries. As soon as I get my pulleys cast I will be on the road testing them. I'll start a thread for my bike build once I have something to show.

PM me anytime. It's good to hear from you. :D

Mike- aka "LightningRods"

Geez. With all these replacement parts for the GNG, I'm thinking you should just go whole hog, source a supplier for good motors and controllers and give GNG a run for their money. I'm seriously considering getting a GNG kit just because you've put so much work into making it better.
 
Timelord said:
Geez. With all these replacement parts for the GNG, I'm thinking you should just go whole hog, source a supplier for good motors and controllers and give GNG a run for their money. I'm seriously considering getting a GNG kit just because you've put so much work into making it better.

Me too, I'm holding off until the entire kit is available from LightningRods. Maybe you could run a http://www.kickstarter.com campaign to ge the capital together for the first batch
 
I want to convert my 9 speed derailleur setup to a 1 speed with a solid chain tensioner, since I am getting a lot of chain skipping/dropping when accelerating hard/jumping and I'll be upgrading to 100v soon which will make the problem even worse.

I was thinking of using the DMR STS single speed kit: http://www.jensonusa.com/DMR-STS-and-Cassette-Spacer-Combo-Kit

With the cyclone 484832T crank set and a BMX chain.

Is anyone else running a single speed setup that could offer some advice/recommendations?

bzhwindtalker?
 
bee said:
I want to convert my 9 speed derailleur setup to a 1 speed with a solid chain tensioner, since I am getting a lot of chain skipping/dropping when accelerating hard/jumping and I'll be upgrading to 100v soon which will make the problem even worse.

I was thinking of using the DMR STS single speed kit: http://www.jensonusa.com/DMR-STS-and-Cassette-Spacer-Combo-Kit

With the cyclone 484832T crank set and a BMX chain.

Is anyone else running a single speed setup that could offer some advice/recommendations?

bzhwindtalker?

That's not too bad of a price. But, if you want to go a cheaper route you can use some pvc pipe that fits over the hub as a spacer for the sprocket. Just cut it to the correct length for either side of the sprocket. You can use a sprocket out of your cassette that is the right size. Then just get a single speed chain tensioner. If you are running a full sus, you might need the dérailleur to handle all the slack when the suspension compresses. Just remove your shifter and set the stop on the dérailleur to hold the chain line.

Hope that makes sense.

Clay
 
Makes perfect sense once you've seen one of the conversion kits in your hand. They aren't really any more sophisticated than that. I love the 9 speed transmission I have but can appreciate the simplicity of dropping all the gears can bring.

I think the 3rd smallest chain ring was the one I was going to use to go SS on my bike (also with a cyclone front setup, but 44t). I have one of the daBomb kits - very similar to the DMR one.
I worked out that I spent the most of my time in that gear when commuting (6th or 7th it looks like on my SRAM display) and could still take off easily from the lights under my own steam. I don't recall the tooth count, but would expect around 16 (my smallest is 11). Motor still provides plenty of enjoyable top speed and torque in that gear.

Bee, are you sure it isn't your belt skipping? I thought I had normal bike drivetrain issues as it felt exactly like chain skip but turned out to be my belt dropping teeth sending a shock through the drivetrain. I had a ~5cm bare patch when I finally got around to removing it. It only reared its head under full throttle or accelerating conditions. Driving miss daisy it was buttery smooth.
 
I had quite a lot of problems with the belt shredding itself when using a derailleur, changing gear sends a lot of shock through the driveline. I decided to fit a Rohloff speed hub which has improved things dramatically, it is unfortunately a very expensive item and I only use about 5 of the 14 gears so it is overkill. A Shimano Alfine hub is much cheaper and is probably more than adequate.
 
bee said:
I want to convert my 9 speed derailleur setup to a 1 speed with a solid chain tensioner, since I am getting a lot of chain skipping/dropping when accelerating hard/jumping and I'll be upgrading to 100v soon which will make the problem even worse.

I was thinking of using the DMR STS single speed kit: http://www.jensonusa.com/DMR-STS-and-Cassette-Spacer-Combo-Kit

With the cyclone 484832T crank set and a BMX chain.

Is anyone else running a single speed setup that could offer some advice/recommendations?

Consider using a stack of single speed cassette sprockets, at least for the middle part of your cassette. You'll probably have to use a normal cassette sprocket in the outer position underneath the lockring, and above 22t I don't think you can get single speed cassette sprockets anyway (and you probably won't have slippage in larger sprockets either).

The reason you might want to try single speed sprockets is because they have tall, uniform teeth that are designed to retain the chain and hold up under constant use. This would necessarily make their shifting less affirmative, but that's a tradeoff you might find acceptable.

Here is a normal Hyperglide multi-speed sprocket. Note the short, rounded teeth that are designed to release the chain at least as much as they are designed to hold onto it:

Hyperglide_Sprocket.jpg


Now compare a single speed cassette sprocket. Note the taller teeth without shift-enhancing features:

33455_5.jpg


You may have to use different thickness spacers to make a stack of these sprockets work right-- 7-speed cassettes have 5.0mm spacing between sprockets, 8-speed cassettes have 4.8mm spacing, and 9-speed cassettes have 4.35mm spacing, so measure the actual sprockets and use spacers that give you the correct intervals.

As far as I can tell, single speed sprockets are available in sizes from 12t to 22t. Surly makes the nicest ones I have seen, and they are the right thickness to be used as a 9-speed stack without spacers. But they are expensive! The plain BMX kind run $5 to $10 each, which adds up but might be well worth it if they solve your problem.
 
Thanks for the advice all. Getting rid of the derailleur and switching to the taller single speed sprocket is my goal here, 16T is my sweet spot at the moment for good top speed and pedal-ability, but the 16T skips when I accelerate too hard. Building my own cassette with single speed sprockets is a great idea, I might give that a try with 2-3 of my favorite gears before ditching the spring tensioned derailleur.

It's definitely not the belt, I have a 11:80 primary chain conversion, which seems to be the source of the high torque problem. I'll need to take a few rides with a camera, I'm worried that the 11:80 is too much torque and that my motor mounts are bending while accelerating. I think this higher torque is also responsible for bending the cheap stock crank the first few times.

I placed my order for a Lyen controller and another pair of 7S batteries. Anyone try 117v yet? :lol:
 
You will love the 100v setup. Just be careful with the phase-amp settings in the Lyen controller. I had it at 95A when i first tried it and felt like accelleretion would rip the bike into pieces.
I got mine at 45A phase current now. Much better Control when wheeleing.
The sprocket slelection for a non-slipping rear-casette setup is interresting. just three gears would be enough. I only use the biggest sprockets when running at 100v.(HG-40 11-34, and they never slip, the smallest does slip) Even if the Power is decreising in the higher rpm because of eddi-currents or whatever, it's still very usefull Power. The range whithout changing gear is extremely wide. I go slowmotion and 55kph in the same gear. Only problem is the twitchy throttle. But the 3-speed switch helps alot. And the more you ride and get a feeling for the bike, the more twitchy power you want :mrgreen:
 
I'm finally making some progress on my first driver pulley for the GNG primary drive. I completed the 3D modeling phase and sent the model off to a service bureau for a prototype. Their machine is a high end German EnvisionTEC that produces stunningly beautiful output. Their main business is jewelry patterns which is what I have used them for in the past. This pulley is a GT2 5mm profile, 18 teeth, 22mm wide for a 20mm belt. The inner sleeve profile was taken directly from the original 14 tooth GNG sprocket. I've put it next to an acetone treated rip rap 3D print just to show what I paid for. This prototype is now off for mold making and production casting. I will be casting this in a very tough zinc/aluminum alloy that has both higher shear strength and higher abrasion resistance than aluminum pulleys. It's been a long slow process but so far everything is turning out perfectly.

Proto_Top.jpg


Proto_Bottom.jpg
 
Nice work Mike!

Makes me wish I'd waited on the chain conversion now. :cry:

Do you have a timeframe for the tensioners?
 
rp3 said:
Nice work Mike!

Makes me wish I'd waited on the chain conversion now. :cry:

Do you have a timeframe for the tensioners?

The chain conversion is not irreversible. My next phase is a 27mm wide pulley (25mm belt) that will fit on a 12mm motor spindle. This is for the hard core performance freaks. I will be offering new steel motor spindles machined to 12mm diameter.

I was working on the tensioners today. I need to get the exact dimensions of the hardware that I'm going to use for the adjusters. After that it's a week for the laser cutting and another week for zinc electroplating.
 
Great to see updates on the wider belt option. I'm wondering what will happen first... finished production of the new pulleys or me getting my tools back from my friend who's putting together his Gen 1.1 this weekend.

Edit: I gathered the parts here in California and shipped everything out to him in Chicago. He's going to hold onto the tools until he logs about 100 trouble free miles.
 
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