GNG 450 brushless Mid Drive - Primary Drive Modifications

[justlooking]

LightningRods m8.
do you have any more of those adjustable kits/sheets left ?? and would you ship to Norwich , Norfolk, uk ??

 

[borschelrh]

I am interested as well for shipping to Hungary.

Thanks
Rick

 

[Cyclebutt]

AWESOME pics! Thanks for posting them in the style of a tutorial. Now you're ready for 72V X 30A = 2100W?...

I'm quite happy with the first bike at 54 volts and 38 amps peak , all I have to do to that one is install the adjustable sheets and get rid of the power robbing tensioner.
I hope this will help others not be afraid to tackle the conversion.

Excellent detailed step-by-step. I'm almost tempted to abandon the belt altogether now. HA! Naw, I'll still do it for the sake of the experiment, but you really have made the chain drive mod look EASY. And for off-road, (most probably, on road too) this has to be the number one choice. Thanks, Denisesewa! Excellent work.

 

[justlooking]

i was wondering if this mod tutorial could be put into its own thread and then pinned and locked ??

i think its great and step by step and is worth keeping on its own for future reference ,,

 

[spinningmagnets]

I've linked to this thread in the original 70-page GNG thread in the first post to make it easy to find.

When I need to get to it, I go to google and search "site:endless-sphere.com gng $400"

 

[stoney]

subscribing and ordering sheets. I truly appreciate everyones efforts. Thank you

 

[Cyclebutt]

My sheets are here! Beautiful laser cut pieces. Thanks, LightningRods! Photo attached:

 

[Mechdude]

Well after around 1000km my belt finally gave way. :-(
So started looking for a local replacement and came across this Gates alternative belt.
http://www.bsc.com.au/sites/default/files/products/manuals/Timing%20Belts.pdf
It's referred to as a Synchro Cog Belt RPP5 and claims to have an advanced parabolic profile. But interestingly it is available as a 465 PCD.
Can anyone confirm whether this might be a fit into the standard design without a tensioner?

 

[Denisesewa]

Well after around 1000km my belt finally gave way. :-(
So started looking for a local replacement and came across this Gates alternative belt.
http://www.bsc.com.au/sites/default/files/products/manuals/Timing%20Belts.pdf
It's referred to as a Synchro Cog Belt RPP5 and claims to have an advanced parabolic profile. But interestingly it is available as a 465 PCD.
Can anyone confirm whether this might be a fit into the standard design without a tensioner?

I believe the 450 fits the standard setup without a tensioner( the very first GNG design), but its a super tight fit, 465 would still require the tesioner, dont know about the profile of that belt fitting.

 

[Mechdude]

Arrh, thanks. I was thinking the tight fit was 460.
Might have to get me'self a pair of adjuster plates.

 

[amberwolf]

i was wondering if this mod tutorial could be put into its own thread and then pinned and locked ??

i think its great and step by step and is worth keeping on its own for future reference ,,

You could copy it over to the ES Wiki in the modifications/tutorials section under Motors, or similar.
http://endless-sphere.com/w

 

[mr.electric]

I think I need to do a chain conversion in my GNG build. The belt is looking a little furry around the edges already.

 

[Cyclebutt]

I think I need to do a chain conversion in my GNG build. The belt is looking a little furry around the edges already.

How many miles?

Sorry about the absence guys, been busy trying to make a buck. Hope to get my sheets mounted some time next week...

LightningRods! Did you make your adjustable sheets installation tutorial yet. I'll do it next week! cheers!

 

[justlooking]

I think I need to do a chain conversion in my GNG build. The belt is looking a little furry around the edges already.

how many miles m8 ?
is your setup standard on 48v ?
is all the mileage on road or off road or a mix of both??

if off road , i
s it track riding or doing jumps ect ?

just trying to get the layout of the belts and what riding makes them wear quicker than others.

 

[Cyclebutt]

I think I need to do a chain conversion in my GNG build. The belt is looking a little furry around the edges already.

how many miles m8 ?
is your setup standard on 48v ?
is all the mileage on road or off road or a mix of both??

if off road , i
s it track riding or doing jumps ect ?

just trying to get the layout of the belts and what riding makes them wear quicker than others.

It appears the belt wear issue is three fold.

1. Jerky starts due to abrupt throttle controller and slack in the drive line caused by having three freewheel devices.
2. Extreme direction changes of primary belt caused by the use of a radical plunger type idler.
3. Sharp edge profile of teeth on drive pulley.

My new belts arrive today. Will inspect drive pulley, modify as needed, install adjustable sheets, and test system without a primary drive idler. Hopefully can report something next week. cheers!

 

[justlooking]

It appears the belt wear issue is three fold.

1. Jerky starts due to abrupt throttle controller and slack in the drive line caused by having three freewheel devices.
2. Extreme direction changes of primary belt caused by the use of a radical plunger type idler.
3. Sharp edge profile of teeth on drive pulley.

My new belts arrive today. Will inspect drive pulley, modify as needed, install adjustable sheets, and test system without a primary drive idler. Hopefully can report something next week. cheers!

can some one elaborate on
2. Extreme direction changes of primary belt caused by the use of a radical plunger type idler

i dont understand the change of direction bit ..
thank you

 

[mr.electric]

Probably under 20 miles here. I am running 48v with a ku123 controller. Chain primary may be in my future...
Pics soon. Anyone have ideas for an easy belt/chain guard to cover up the workings? The "no gas gas " build looks great with the carbon covers.

 

[Miles]

can some one elaborate on
2. Extreme direction changes of primary belt caused by the use of a radical plunger type idler

i dont understand the change of direction bit ..

Flexing of the belt as it goes around the drive pulley (internal) and then the idler pulley (external).

 

[spinningmagnets]

The fibers inside of the belt will wear out much faster if they move in an "S" instead of a normal "U" path.

 

[fizzit]

It also helps if the tensioner is larger, so the belt has to bend less. The HTD bible says that a tensioner wheel should be larger than the smallest sprocket used.

 

[justlooking]

LightningRods

just got my adjustable sheets today ,, thank you LightningRods ,,very quick delivery to the UK, and i wasn't charged any duty by the government so well chuffed ,,

 

[mr.electric]

This is the GNG build I have been working on. Belt died today. Time for a chain conversion ....

 

[querlenker]

Hello,

I recived my GNG kit yesterday and dismounted the motor. The quality of the mechanic stuff is poor, but you get what you pay for, i wont complain about it. I am thinking of doing a geared primary reduction and asking myself if there is any problem in running the motor in reverse direction. What do you experts mean ?

Best Regards, Sebastian

 

[LightningRods]

Hey Guys- Sorry for the absence. I been chasing the almighty dollah. Gotta pay for those e-bike parts.

First of all, yes I have the adjustable sheets tutorial up. The url is: http://www.backusstudio.com/gng/

I've posted this over on the main GNG thread but I'll repeat it here. I've developed and I'm getting ready to have made adjustable bottom bracket sheets. They should be available by mid February. I'm also working with a pulley and belt manufacturer to have custom 20mm wide pulleys made for the GNG that are as good as we're going to get them. I'm enlarging the driven pulley from 80T to 100T. That's 25% more primary reduction. The tech also recommended AT5 belts rather than a HTD belt. It's still a 5mm pitch but is "much stronger".

I'll have this drive setup manufactured and try it first on my own bike. If it still doesn't work I'll give up and convert to chain. If it does work I'll make the pulleys and belts available to anyone who wants a set.

Belt drives work on everything from racing Karts to computer drives to heavy industrial machinery. Matt Schumacher makes them work on his own custom e-bike drives. There's no reason a properly made belt system shouldn't work on the GNG.

 

[LightningRods]

This is the GNG build I have been working on. Belt died today. Time for a chain conversion ....

Great looking bike, Mr. Electric! Perfect for the GNG mid drive. Am I seeing correctly that the parcel rack moves with the rear suspension?