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

To my knowledge, the 1.37 and the 1.375 are identical pitch diameter threads and have been for some time. Difference being the tips of the threads are shortened/flattened .005 to allow more wall / less stress concentration on the female side on thin walled bb components. As long as the male threads don't come to a sharp point, there should be no issues anywhere on interchangeability. The stock gng crank arms were a poor example of suitable thread quality on my set, but were very snug, and so much better than loose in my book.
 
speedmd said:
To my knowledge, the 1.37 and the 1.375 are identical pitch diameter threads and have been for some time. Difference being the tips of the threads are shortened/flattened .005 to allow more wall / less stress concentration on the female side on thin walled bb components. As long as the male threads don't come to a sharp point, there should be no issues anywhere on interchangeability. The stock gng crank arms were a poor example of suitable thread quality on my set, but were very snug, and so much better than loose in my book.
Thanks for that, kinda explains why I havnt had an issue with any of my trials stuff.
 
I thought I would have a little more time to shop for my rear wheel upgrade, but I went for another ride at 3000 watts and the rear sprocket is crumbling in short order. The first and second gears seem to have broken/separated in the freewheel. The higher gears seem to be one piece though and are holding together.

The only good news I have today, is that I replaced the inner 38t chainring with 44t and got up to 37 mph. I may be joining the 40 mph club soon. :mrgreen:

Those of you who are running 3000 watts plus, what rear hub/rim are you using?

Thanks!!!
 
LightningRods,

I want to tell you that I am very impressed by the dedication and professionalism on the gng subject...thank you for that :D

What is the diameter of the 90T and 120T?
were can i buy 20mm belts?
do plan to do 25mm?

thanks
rojo toro
 
speedmd said:
To my knowledge, the 1.37 and the 1.375 are identical pitch diameter threads and have been for some time. Difference being the tips of the threads are shortened/flattened .005 to allow more wall / less stress concentration on the female side on thin walled bb components. As long as the male threads don't come to a sharp point, there should be no issues anywhere on interchangeability. The stock gng crank arms were a poor example of suitable thread quality on my set, but were very snug, and so much better than loose in my book.

In the description from the ENO it seem to be different sizes...

http://www.tartybikes.co.uk/complete_freewheels/white_industries_eno_trials/c16p77.html
 
Hi E-Norco

What I understand is that in the 2008 - 2009 time frame the former "compromise" thread 1.37x24 standard was abandoned. It was essentially replaced by the 1.375x24 ISO 6696 standard. The pitch diameter standards and gauge limits are specified in much greater depth in the new standard and are virtually identical. Remember 1.37 or 1.375 is the overall diameter and not the critical pitch diameter, and we are talking roughly .002" per side on a theoretical tip of thread (male) and root of thread (female) side of which there was a great tolerance to begin with. There should be no interchangeability issues between them. That being said, I would never suggest that every thing out there meets acceptable quality standards. Too many years in the quality business to take anything like this for granted.

cheers
 
speedmd said:
To my knowledge, the 1.37 and the 1.375 are identical pitch diameter threads and have been for some time. Difference being the tips of the threads are shortened/flattened .005 to allow more wall / less stress concentration on the female side on thin walled bb components. As long as the male threads don't come to a sharp point, there should be no issues anywhere on interchangeability. The stock gng crank arms were a poor example of suitable thread quality on my set, but were very snug, and so much better than loose in my book.

Here is a direct warning from Trialtech regarding exactly this issue:

"Please note that the minimum required thread contact between crank arm and sprocket/freewheel is 7mm, and a 1.37" sprocket/freewheel with maximum internal thread diameter 33.80mm (NOT 1.375") must be used. Failure to adhere to this instruction will damage the cranks threads and this is not covered under warranty."

I bought both a flanged ACS 1.375" and 16 tooth ACS 1.375" and neither of them fit the GNG pedal crank or freewheel to 12mm shaft adapter. A mechanic friend of mine made the same comment about the thread peaks causing interference so I filed them down. The ACS freewheels still would not thread on past a couple of threads. The diameter fit feels loose after filing. It's the threads that bind up eventually.

I don't claim to have the answer but I don't think we have an answer here yet.
 
I think trying things on the GNG components will not supply the answer as I am convinced the machine work and CC is terrible ,both of my kits have shown differances. I think you are going to have to pick some components that "do" match and build your stuff around them, most of the GNG stuff isnt worth keeping if you are upgrading anyway and those who are interested in your parts should be willing to pay the differance.
 
Hi Mike

Easy enough to measure the pitch diameter of the external threads with three wires and a micrometer if your good with them. Willing to bet you will see that the pitch diameter is way off (big) on the GNG threaded arms. Machinery's handbook has this inspection process in detail. Forget measuring the inside threads. Plug gauges used for that. Not sure where the 33.8mm/1.331" comes into the picture unless they are calling this "internal thread diameter" instead of what has been universally accepted as the "minor diameter". The ISO 6696 has the latest breakdown but can tell you from experience that they are typically not worth buying these ISO specs unless your making taps / dies or gauges. My opinion is that if the spec is kept from the public, it is relatively worthless to use as a reference. They have created there own little monopoly.

1-3/8x24 is 1.3466- 1.3423 pitch diameter. Internal minor diameter is 1.330 -1.340. If you don't' have a handbook let me know and I will look up the correct wire sizes for you.
 
KONA 12.JPGKONA 4.JPGHaving followed this thread since about page 20, it is time to share and give back to all those ideas I was inspired by or just plain copied. I had a couple of Kawasakis when I was a teen living in the boonies and always missed it. Motorcycles are no fun for me in the city, the electric trail bike is perfect. People are always muttering disparagingly about the Ego kit but it seems to me Bosch has been making motors since there has been motors and the planetary reduction is probably better made. It is more of an out of the box thing where mine was more labour of love. GNG got me rolling and I love the DIY part. I have upgraded here and there and I am pretty happy with my bike.
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I started with this Kona I found locally because I liked the shape of the frame and I wanted the massive brakes and suspension, reminding myself that this project was instead of getting a motorcycle. I initially installed the GNG with the L-Rods upper and lower sheets. I developed a good system for tensioning the upper and got the belt as tight as I dare but it would skip even in the lowest gear. After 164km the belt was too shredded so I swapped in the original GNG sheets with the "dreaded" serpentine wrap. Recently, when I tested a set of pads I threw in the rear brake, lifting the back wheel off the ground, I applied full throttle and gradually squeezed the lever.I could slow the wheel down to barely moving and the belt did not skip.
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When my GNG kit arrived, I first plugged it in on the bench just to test it. It was unusable. The bolts on the jack shaft holding the freewheel sprocket and the belt pulley were so tight I could barely rotate it. It used so much power even under no load I can't imagine it lasting very long. Plus, it chewed the edge of the belt after running for about ten seconds so the alignment was off too. When disassembled, I filed the edges of the teeth on the pulley and on the motor too. I tiny hobby file worked well on the motor. It actually had a burr on the edge. It took a while, but I only did one edge of each tooth because it only ever spins one way. Then I put them both to the polishing wheel with the most aggressive polishing compound I had. Now after almost 600 km on the current Goodyear belt, it still looks new. Reassembled the jack shaft properly, with lock tight, I can spin it with my pinky.
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I went with the nano-tech lipos for the high energy density. At 16Ah, I never use more the 85% so on a typical ride of big hills, trails and paved path, the pack usually lasts longer than I do. I like the stealth and safety of the back pack arrangement. One of the best bits of advice I would give to a new builder is to not cheap on batts and charger. A great bike is no good without battery power. They are expensive. Less weight on the bike is good for me as I often take it down the narrow basement stairs. My charging station is on my desk where I never take my eyes off them while they charge. Good excuse to surf ES. I cringe when I see pics of bikes with batteries cable tied to them. These batts are very fragile naked and puncture easily. Ever fallen off your bike? A short can cause a chemical fire you will never put out. I modified a big computer power supply for my chargers but don't recommend it unless you you confident with electronics. The whole deal has very high potential energy and should be with respect and a bit of fear. This can burn your house down easily.
KONA 9.JPG
KONA 10.JPG
I shortened up all the wires and put the controller and bits in a baby pelican case. After some muddy trails, I power wash it to within an inch of its life at the car wash on the way home. It also makes it look tidy. Ahhh! you are thinking it will get too hot. No, only a bit warm. I leave it ajar on super hot days but don't need to. The breaker is for common sense but it is nice to shut it off to (dis)connect the umbilical. I got rid of that GNG yellow piece of poo the motor wires are coupled in and used bullet connectors sealed in heat shrink.
View attachment 6
The fender on the front is made from ABS plastic. I love that material. I have made all kind of things from it. It is super easy to work with and is cheap and available. I even carved a shifter trigger as I had to cut the original off to clear the throttle.
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View attachment 4
Curious how others get their kit to work at all without a torque arm. This was the first mod I did. This one is adjustable as are my lower sheets.The Cycle Analyst is neat but overkill for my purposes. All that is required is a Ah meter.
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The GNG bottom bracket short falls are well documented. These I can confirm. The roughest riding I do is hopping on/off curbs but the spindle bent in short order and the free wheel got sloppy and grindy. Plus, the right side left side sticker was backwards. Took me a few minutes to figure that one. Installed the cyclone bits like every one else.
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No mods to the controller yet. Some people are putting 2,3,5K into the motor...it is a bicycle after all. I have already ruined the rear wheel bearings and the forks need to be rebuilt. It has to last a season anyway. I don't want to have to push it home. 5K for how long? O.K. in some dragsters they don't even give it a radiator because the race is only seconds long. 1000 watts stock is fine for me. I don't even know what my top speed is. A big road is the only place to wind it out and my inclination is to avoid cars and people. Its about hill climbing and muddy trails. It is so unnatural to go up a steep hill on a bicycle its a blast.
KONA 7.JPG
Has any one else found that bike mechanics are weirdos? Tool kit and a god complex? The guy that services my Mercedes is down to earth, friendly and treats me like his son. I went to a local bike shop in Toronto and was told "We don't sell downhill bikes" sniff sniff. They did however have two nice 2.5" downhill tires on sale for $10 each. I buy the Park tools and fix things myself.
no bikes.jpg
Wow I live in a city that really hates bikes. The car is King. Our lousy mayor commenting on a recent cyclist fatality said "My heart bleeds for him but its his own fault". In High Park or on the waterfront "multi use" trail, pedestrians stink eye anyone on two wheels. In their minds they aren't walking, they are drivers that just have their cars parked for twenty minutes. I do find it surprising how unnoticed I go as an EV. Totally illegal but most people just see a big mountain bike. I actually had a traffic cop stop traffic to let me cross the street. Shocked-I have issues with authority.
I like to think of my bike as the SUV of bicycles. This is so much fun, have put 900 km on so far. I find myself laughing while I ride. Peace.
 
It looks like the trials crank folks are still using the old standard and going overboard on the mating parts spec. Park tools has listed the female minor diameter tolerance of the 1.37 x 24 threads at 33.6 -33.9 mm or 1.3228 -1.3346" If they require something tighter than the spec (33.8 max), it must be a borderline situation strength wise the way they cut the threads or due to the added torque of the little freewheels/ long crank arms and a big aggressive rider hopping on it, that they fail quite often. They would be much better off cutting the crank threads the newer slightly larger 1.375 size than sorting through freewheels for a tight fit. Just a thought.

Looks like good quality steel wire .035 -.036" diameter would work well to gauge pitch diameter well for this size external thread so you can see what your up against on the cranks from the east.


cheers
 
Scrone, welcome...and the front splash-guard is awesome. I have been pondering a good cover for the kit, as a mud-guard to help the parts last longer, plus a "pants-guard" to keep the belt/chain from shredding clothing or a finger. I like how yours runs up all the way to the head-tube. I am thinking I would like the side-panels of a cover to be clear, so the internal workings are still visible.

I added your link to the third post on page-1.
 
scrone said:
Has any one else found that bike mechanics are weirdos? Tool kit and a god complex? The guy that services my Mercedes is down to earth, friendly and treats me like his son. I went to a local bike shop in Toronto and was told "We don't sell downhill bikes" sniff sniff.

Would you consider your Mercedes mechanic a weirdo if you asked him to sell you a desert racing truck and he told you he didn't sell those? Seems like much more of a weirdo thing to use an off-road downhill racing bike for riding on the street.
 
I have a problem with the trottle that came with the GNG. The reaction of the trottle is to nervous.
Anybody a good advise for a replacement?
 
Secret1511 said:
I have a problem with the trottle that came with the GNG. The reaction of the trottle is to nervous.
Anybody a good advise for a replacement?
Here is how I did mine using a magura throttle, it will help but to get it really smooth you will need a programable controller like the "Lyen 12 Fet" along with the Magura.
http://endless-sphere.com/forums/viewtopic.php?f=28&t=46891
 
It appears that 1.370" is standard English and Italian BB thread. It's referred to as "35mm" but the spec is 34.6-34.9mm OD. 1.375" equates to US 1 3/8". It's MUCH easier to get taps and dies for 1.375". I've written ACS and White Industries asking for their take on this. I'll let you know what I find out.
 
Having lurked on ES for a while and having finally made it through 106 pages.:) I have decided that this kit seems to be a good choice for my first ebike.

Has anyone heard of Hallomotor? The company seems to have a very good price, including lcd display. But has anyone bought the gng ( or any) kit from this factory? What was their delivery times like, communication, packaging and delivery charges (I'm in the UK) and their controller max cut off is 25Amp.

Thanks for your help,

Charles

http://www.hallomotor.com/wholesale-48v-500w-brushless-geared-mid-drive-motor-ebike-conversion-kits-2.html
 
Hi LR

The 1.375x24 is the new ISO standard. I would not waste time with the old ones. 1.37 was a compromise bicycle thread to begin with not a UNF and anyone still making stuff to that is just asking for trouble. Here is some more on measuring the male thread. You will need a 2" micrometer and three sections of identical size wire/ drill bits(shanks). Mine is tightly assembled and I don't have the freewheel tool or I would measure it. Will worry about taking it apart when it dies. If you have a set of arms free, let us know what you get for Pitch Diameter.
Good write up in Thun.
http://www.thun.de/fileadmin/user_upload/documents/Glossar/Assembly_gb.pdf
Sheldon Brown has some on it also.
http://www.osbornproducts.com/three_wire_method_measuring_pitch_diameter.htm
http://dc308.4shared.com/doc/KyDHhvij/preview.html

three_wire_method_fig1.png


P05-01.png


three_wire_method_fig3.png


three_wire_method_fig5.png


wire.JPG


preview_html_1a95fb17.png
 
Denisesewa said:
Secret1511 said:
I have a problem with the trottle that came with the GNG. The reaction of the trottle is to nervous.
Anybody a good advise for a replacement?
Here is how I did mine using a magura throttle, it will help but to get it really smooth you will need a programable controller like the "Lyen 12 Fet" along with the Magura.
http://endless-sphere.com/forums/viewtopic.php?f=28&t=46891

Yess i have a lyen controller. Are there settings i need to know?
 
Secret1511 said:
Denisesewa said:
Secret1511 said:
I have a problem with the trottle that came with the GNG. The reaction of the trottle is to nervous.
Anybody a good advise for a replacement?
Here is how I did mine using a magura throttle, it will help but to get it really smooth you will need a programable controller like the "Lyen 12 Fet" along with the Magura.
http://endless-sphere.com/forums/viewtopic.php?f=28&t=46891

Yess i have a lyen controller. Are there settings i need to know?

First make sure your wiring is as follows >>
Controller: Motor:
HALL:
Yellow Yellow
Green Blue
Blue Green

PHASE:
Yellow Yellow
Green Blue
Blue Green

In the program I set my Phase amps to 76
Rated current 34
block time to 5.0
speed limit to 99%
of course set your LVC to correspond to the battery you are using, mine is 43 volts for 14S battery

These are the things along with the Magura throttle and Cermets I found made the throttle managable and provided the best power to efficiency . FOR MY SETUP ( gearing, riding style ect) !!!

There are others here who understand this stuff much better than I do

If you are going to buy a Magura get it from Holmes Hobby, In the coupon box at check out type in "SHIPPING", if its still a good code you will get free shipping.
Anyone else feel free to correct me if any of this doesnt seem right, been working for me just fine for almost a year now, but what do I know :roll:
 
The posts about 1.375 X 24 threads is important and has a much wider interest and application around ES. Would anyone mind if I started a separate thread about this? The end results should be in the technical reference section for future use (instead of digging through a 107-page thread to find a link).

EDIT: Please continue the important 1.375 X 24 thread discussion here:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=54237
 
spinningmagnets said:
Would anyone mind if I started a separate thread about this?
I know you ask out of respect for others but with all the time and energy you spend making life easier for the rest of us you shouldnt have to. You are Much appreciated my friend !! :)
 
Hi spinningmagnets

Agree, it is getting lost among the other thread topics and some good reference details to have handy and tons of misinformation out there.

It applies to both BB and freewheel and hub specifications in bike world. Was thinking the strong freewheeling crank and any hub / freewheel sections should also show a link. With the horse power our group is running into these threads, we should be setting the standard revisions/ updates and not relying on a stagnant proprietary ISO bicycle thread spec. :)
 
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