2016 GNG EXTREME BELT MID DRIVE BUILD. PROS & CONS

Ecyclist

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Joined
Apr 1, 2016
Messages
480
Location
San Diego, California
About 4 months ago, I started to read about e-bikes. I didn't have a clue what I was getting into so I searched through the pages of the Endless Sphere posts. It is a jungle of info, and I'm starting this topic to help potential e-bike builders make their life a little easier.

First of all, you should know that this is fun and rewarding hobby, but it is not cheap. If you plan on using an e-bike for basic commuting, then you will be relatively happy with installing BAFANG kit to the bike that you already have. This will be your least expensive option if you consider time and money. 1000W kit with an OK battery will set you back about $1200. You will still need to know how to remove the BOTTOM BRACKET from your bike and install the kit. Also you will have to figure out how and where you will install the battery. That is what was recommended to me by an experienced builder.

I decided on getting the GNG kit because I wanted to learn more and have the flexibility to change the kit to my preference.
The kit, including controller, hardware and shipping was $630. The kit arrived well packed from Hong Kong in 6 days.
You will still need the battery ($375+shipping) with charger ($79.95) and CA3 ($130+shipping) with shunt ($20). I bought both from LUNA CYCLE. Please note that Cycle Analyst will make all the difference in the world and is worth every penny. It will smooth out power delivery and make your drive train very happy.
I installed it all on the like-new 2005 Giant Trance 2 that I bought on craigslist for $500.
Bike 1.jpg
I think that mountain bike is a way to go.

Now the big question is, am I happy with the final result? YES
Would I recommend it to others? MAYBE

First of all, it is a Chinese product and it is unfinished. Stainless steel mounting brackets (.105" thick) and stainless steel guards (.043 thick) are razor sharp.
You will need to file all sharp edges or you will be sorry.
The mounting bracket that connects motor to the bottom bracket of the bike is bent too wide, and small washers were used to fill the gaps.
This was not adequate. I had to make thicker spacers so both sides of the bracket were parallel to each other.
That produced another problem - mounting bolts couldn't reach nuts all the way.
I counter-sank the bracket and machined the bolts to match, in order to solve that problem.
One of the bolt’s head was crudely ground down, so that the head was lower. This was done to produce clearance between the bracket and the chain ring mounting bolts; kind of pathetic. The countersink bolts should be used in the first place.
Triple chain rings, 2 for the bike chain and 1 for the go-cart chain are connected with 4 bolts. 12 spacers (5 mm long) between the chain rings were saw cut (low quality).
5 mm spacing for the bike chain is too wide. I machined all new spacers and made the bike chain ring spacer 4mm (.157") long. So I made four 10 mm spacers and four 4 mm spacers. I had to shorten the chain ring mounting bolts to accommodate.
I machined all other spacers to streamline mounting of the guards and attaching the front of the kit to the frame. (I don't like the hose clamps attachment idea) This also allowed me to install bolts deeper and install counter-locking nuts.
I removed and adjusted both freewheels.
I’d never disassembled freewheel before, and I lost a few balls on my first try. I ordered 100 extra balls from McMaster Carr and finished the job.
Both freewheels had a bunch of low quality grease inside. Once I removed the grease, I could tell that freewheels were too sloppy. I removed one spacer from each freewheel, and that did the trick. After that, slack was .003 to .005" instead of .022 to .025".
Bike 2.jpg
Bike 3.jpg
TBC.
 
Second stage has ratio of 6.66 to 1. The 219H chain is running on 12T and 80T sprockets and is preloaded with spring tensioner. I only had to shorten the tensioner’s post to put it in line with a chain.
I was not happy with the first stage build (5 to 1 ratio). The small pulley 16T was slipped and then screwed onto the motor shaft that had a threaded end.
This was all good until you wanted to remove the pulley. I redesigned the pulley for future use. I had to open the motor to remove the pulley.
The motor looked really cool inside.
Motor.jpg
I drilled out the thread and machined the key slot. The motor shaft had a key slot already in it, so I installed the 4mm key and put it all together with a custom nut.
Small pulley.jpg
Large pulley 80T needed deburring. I also cut two flats on a large, gold anodized nut that connects jackshaft to the pulley via freewheel.
That allowed me to tighten the shaft to the golden nut.
Large pulley.jpg
Total reduction of the kit is 33.3 to 1 and with 48v battery the bike cadence with no load and off the ground is 95.
Belt tensioner with two jack bolts works fine.
GNG belt drive adjustment.jpg
I built a junction box with a kill pull switch.
Kill switch.jpg
The kit is very rigid and quiet. I anticipate that it will work fine.
I'm planning on using it for a month or two and afterwards convert it to a planetary transmission mid drive.
This will be my second stage of the learning curve.
CONCLUSION
I'm OK with my choice of the kit because I learned a lot.
If you are on the market for a belt mid drive kit and you don't want or can't work out all little problems that come with a GNG kit, then you should go for the LIGHTNING RODS kit. You will buy a kit that works well out of the box and comes with support that you will never get from a Chinese seller.
My 2 cents.
 
In the past, I used the bed of my truck to take my bike places.
Since I will be taking my new e-bike for test rides, I figured that it would be nice to build a rack that complemented the bike.
I started yesterday and I'm done. The bike has only 3 contact points with the rack, 2 tires and 1 pedal. The pedal pedestal is adjustable so it can fit my other bikes.
In addition, the rack can be used as a flat bed rack or floor stand. Front of the rack has ¾ diameter hole drilled through. It can be used to put ¾ pipe or shaft to stabilize the rack side to side.

E-bike rack 1.JPG
E-bike rack 2.JPG
E-bike rack 3.JPG
 
izeman said:
you're allowed to mount that on you car? no lights? license plate hidden? man i envy you ... rules are sooo strict here. we even have to get a special license plate for the bike rack and it needs to have signal light, brake light etc.
Look on the bright side, you live in one of the most spectacular cities in the world. In my book, right on par with Paris.
BTW: I looked up your KONA Entourage build and I'm very impressed.
 
Ecyclist said:
izeman said:
you're allowed to mount that on you car? no lights? license plate hidden? man i envy you ... rules are sooo strict here. we even have to get a special license plate for the bike rack and it needs to have signal light, brake light etc.
Look on the bright side, you live in one of the most spectacular cities in the world. In my book, right on par with Paris.
BTW: I looked up your KONA Entourage build and I'm very impressed.
thx :)
 
Ecyclist,

really? You want some answers and in your picture you have a pistol pointed at me. You are insane! I thought there just was a shootout in SD?
 
DingusMcGee said:
Ecyclist,

really? You want some answers and in your picture you have a pistol pointed at me. You are insane! I thought there just was a shootout in SD?
Dude, I just think that girls with guns are sexy and I'm happy she got your attention.
If comes to shootings they are everywhere.
It is reality of our times whether you like it or not. REALLY
 
Ecyclist said:
DingusMcGee said:
Ecyclist,

really? You want some answers and in your picture you have a pistol pointed at me. You are insane! I thought there just was a shootout in SD?
Dude, I just think that girls with guns are sexy and I'm happy she got your attention.
If comes to shootings they are everywhere including NY were guns are illegal.
It is reality of our times whether you like it or not. REALLY

Gun talk has no place here. :roll:
 
amberwolf said:
https://en.wikipedia.org/wiki/Gun_laws_in_New_York#New_York_City
It looks like I can't trust what I read in the paper or on the net. Thanks.
 
ignore the anti-gunners 8)

glad to see someone actually using the latest from GNG. i have the older version that i converted to chain. i like it better than my BBS02, except for that cluttered look

zSAo1Ug.jpg
 
I am interested!
Please PM me as I am in San
Diego and would Like to share
( what little bit I have ) with you.
Maybe we can meet up.

Bob K
 
Overclocker said:
ignore the anti-gunners 8)

glad to see someone actually using the latest from GNG. i have the older version that i converted to chain. i like it better than my BBS02, except for that cluttered look

zSAo1Ug.jpg
Thank you for posting. I'll keep it in mind if my first stage goes belly up. So far, I have no problems.
Is your new chain set-up as quiet as the belt drive?
Do you use CA with your mid drive?
 
Nice build! Just wondering....Why did you get this over the Cyclone? I'd love to hear more about how you like it and how it behaves on the trail. What chainrings do you have up front other than the 80T? Nice bike rack!
 
robocam said:
Nice build! Just wondering....Why did you get this over the Cyclone? I'd love to hear more about how you like it and how it behaves on the trail. What chainrings do you have up front other than the 80T? Nice bike rack!
I decided on the 2016 GNG kit for number of reasons. I like the modular structure of the GNG kit. With this type of arrangement
I can swap belt/chain transmission with planetary transmission that I already have.
Cyclone motor is too chunky and, I think, it needs larger battery. I'm sure that Cyclone is a good choice, but it is not for me. Personally, my first choice would be Tangent Ascent, but I think that it is too noisy and produces some unusual vibrations. I took it for a spin at Sea Otter Bicycle Show. My kit came with 32/42 chain rings, and I almost never use 32 ring. I'm planning to swap 32 for 50 ring. So far, I've run the motor up to 1200W and it pulls the bike up a pretty steep hill at 18 mph. I can pedal up the same hill at about 5 mph. Plenty of torque for my taste. I made over 250 miles and had no problems. The only draw back about the belt drive is that if you ride through tall grass or weeds, the transmission turns into a weed eater. It happened to me once. I noticed change in a sound of the kit, but 5 minutes later it was back to normal. I see that you're using the GNG kit yourself. Can you post your CA settings so I can try them on my kit? Thank you in advance. Let me know if you have more questions.
 
Ecyclist said:
Thank you for posting. I'll keep it in mind if my first stage goes belly up. So far, I have no problems.
Is your new chain set-up as quiet as the belt drive?
Do you use CA with your mid drive?


yours should hold up well because of the wider belt and presumably better designed drive pulley. speaking of which, how many teeth do you have on the drive pulley?

let us know how the belt holds up long-term

oh the chain is really noisy! that's what i miss most from the belt system. but i'm mostly using the BBS02 now which is probably quieter than the GNG belt

no CA but i did change to a "torque simulation" controller which smoothens out your throttle input. the original controller was very jarring to the drivetrain components...
 
I have to second the compliment on your rack.
Clean work. I like the tie-down brackets.
Are you happy with them, rigidity wise?
Also, where do you like to go ride?

Bob K
 
Bob K said:
I have to second the compliment on your rack.
Clean work. I like the tie-down brackets.
Are you happy with them, rigidity wise?
Also, where do you like to go ride?

Bob K

Thank you for the thumbs up.
Good question about rigidity. At first, I was not happy with the rack because the bike was rocking side to side, so I came up with the pedal pedestal and that solved the problem. At this point, I'm using a bungee cord to keep the pedal and the pedestal together, but in a few days I will make some kind of a quick clamp. We have bunch of dirt runs around my neighborhood that I ride on a regular basis. I also like Lake Miramar and Peñasquitos Canyon Preserve, but those two are a little flat for hard core mountain riders. I'm an old fart, so they work for me. :roll: I assume you live somewhere close to the western end of that preserve.
 
Yeah, I have to see if I can use the San Clemente Canyon trail to work with.
If I can , there are a lot of "connectors" to the canyons of Clairemont and
Tecolote and I would imagine a via through Sorrento Valley to Penesquitos as well.
I also ,deal with advanced chronology along with a "not so new" knee
and that's why I am looking into electric bicycles as an entertaining
outdoor sport.
I still want to check out your bike though.
 
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