my First build GNG middrive, Sp. bighit dh 6x 6s5000mAh lipo

[christerljung]

Trying to figure out the perfect batterysolution.
With this woodblock i can get a plastic box vacuum Formed. It would be nice, no possible shortcut and a smooth surface for the lipos.

This way with aluminium the size can be absolutely perfect to fit the bike. But scary for shortcuts.

 

[christerljung]

Today the wodden chainguide was replaced with the more fancy looking truvative original one.
It was some hours of work to make it fit between the frame and the bulkier GNG crank/sprockets.

I had to drill a hole in the GNG mounting bracket to get access to mount hole. Then rethreading to M6.

This way was too thick.

But this one was perfect

Finally i was too excited about getting it out for a ride and crossed polarity... luckily i had gloves on...

 

[rodgah]

so you could of used a 1 piece chain device like this without modification?

 

[christerljung]

@Rodgha: Thats possible. There is only about 1.5mm space for the mounting plates.

 

[christerljung]

Video from todays riding and testing of secondary idler. Changed cassette from sram 9-speed to a standard HG41 7-speed, no jumping gears anymore:

[youtube]m2pxP2FJ7EE[/youtube]

 

[litespeed]

So what kind of speed are you getting out of 72 volts? Motor temp? Range? Looked really good but with the fuzzy video I couldn't make out the speed.

Tom

 

[christerljung]

Hi Tom! Its about 50kph top speed and motortemp gets a little warm. (not hot)

 

[litespeed]

Thanks for the info.

Tom

 

[Cyclebutt]

Video from todays riding and testing of secondary idler. Changed cassette from sram 9-speed to a standard HG41 7-speed, no jumping gears anymore:
Like the chain guide, having similar issues, both chain rings jump chains. Any pictures of your secondary idler? I see you eliminated the primary belt drive idler. Is that working out okay? I'm considering replacing my secondary idler with a roller. I forgot to put the chain guard back on after some troubleshooting and the jackshaft chain kept coming off. Little idler cog was allowing the chain to cock sideways on it's way to the chain ring, which was causing the problem. Chain guard helps correct this issue but a roller idler might eliminate it. Chain guides seem to be a MUST HAVE for this set up.

 

[christerljung]

Hi! Yes the chainguides are important indeed. I havent had any trouble with the idler on the chain side, so far. But my main-chain is still coming off and started jumping coggs in lower gears again. Maybe i will try a Wipperman chain. But first i´m gonna take off one or two links, the chain is too long.
I still have the original primary idler on the belt. But also a secondary idler, see pics. This secondary idler doesnt allow the belt to slip under heavy load at 72V. But belt was like an old rubberband after 50km. Dont really know what to do with the belt design. Its just too weak for 3Kw, probably need a double chain or a 25mm wide belt for some reasonable reliability when riding it hard at 72V.

 

[Cyclebutt]

Here's another mid-drive I like, would try.

http://endless-sphere.com/forums/viewtopic.php?f=28&t=44572

Looks like better quality than the GNG and much simpler in design. As I am already committed to my GNG kit I'll just watch their progress while we continue to "patch up" the design flaws of our GNG's. Mid-Drive RULES!

 

[Cyclebutt]

Home made chain guide.

 

[christerljung]

That seems like a great setup!
Had mine adjusted, it has a similar look and works just fine, was out for a ride today.
New speed record btw. 65kph!

 

[Cyclebutt]

65Kph! Nice! Ordered an 8-speed trigger shifter, cassette, and derailleur Saturday. Should have the chain guide finished long before they arrive. Ride ON!

 

[sigimem]

Hey nice build looks like the Gng Kit is good choice for serious offroad riding.

Can you tell me your Controller settings? like battery amps phase amps and block time?

 

[christerljung]

Hey nice build looks like the Gng Kit is good choice for serious offroad riding.

Can you tell me your Controller settings? like battery amps phase amps and block time?

Sorry, i had the controller programmed in advance from Lyen. But i will read it over to computer in a couple of weeks and let you know.

 

[Cyclebutt]

Hey nice build looks like the Gng Kit is good choice for serious offroad riding.

Can you tell me your Controller settings? like battery amps phase amps and block time?

Sorry, i had the controller programmed in advance from Lyen. But i will read it over to computer in a couple of weeks and let you know.

Spinningmagnets, covers all stock GNG 450watt brushless kit data at this thread:

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