Bafang BBS02 14s lipo

[Topdonkey]

Finally got all my batteries and converted from 12s lipo to 14s lipo, and wow, there is a huge difference in power, and strangely, its also quieter too ?

Biggest problem now though is that my bike is flexing in the middle when i apply full power, if i look down at the crank as i give it full power, i can see my crank move out of alignment by about 15mm which looks scary, you can feel the bike pull slightly to the right as i accelerate hard.

Next problem, is that once you hit 44mph, the display magically drops to 24mph and very slowly climbs to 25.5 mph whilst my speed is obviously accelerating faster than this, are there any known bugs at all in the 750w bbs02 ?

 

[Fordulike]

Biggest problem now though is that my bike is flexing in the middle when i apply full power, if i look down at the crank as i give it full power, i can see my crank move out of alignment by about 15mm which looks scary, you can feel the bike pull slightly to the right as i accelerate hard.

Next problem, is that once you hit 44mph, the display magically drops to 24mph and very slowly climbs to 25.5 mph whilst my speed is obviously accelerating faster than this, are there any known bugs at all in the 750w bbs02 ?

Are you sure that the bottom bracket locknut and locknut cover are both torqued to the correct setting?
I would be worried, if any part of my bike was flexing or moving about that much

When you hit 44mph, is the motor assisting you at that speed, or are you reaching that speed down a hill without assist?

 

[Topdonkey]

The locknut and cover locknut are definitely done up properly, nothing loose around there at all, I'm thinking that possibly the bike isnt up to the amount of power going through it as its a 2004 Giant AC1 and was a pretty flexy bike when it was brought out new, adding this much power just seems to make it flex even more.

It only does 44mph downhill with assist and me pedalling (like a mad thing!!), on the flat its cruises at 32mph on throttle only

 

[Topdonkey]

 

[Fordulike]

It only does 44mph downhill with assist and me pedalling (like a mad thing!!), on the flat its cruises at 32mph on throttle only

I'm wondering if the display is going a bit quirky, once you are going faster than the maximum speed limit, set in the display special settings.

According to the Bafang manual, this can be set for a range from 12km/h to 60km/h (7mph to 37mph)

Another cause, could be that your speed sensor and magnet need to be better aligned, or brought closer together.
I had this same problem on a non motorised bike, with a wired speedo and sensor. It would become erratic at higher speed. A bit of adjustment to the magnet, made it work properly again.

As for the flexing... happy wobbling

 

[Fordulike]

View attachment 11412

That's your problem, try riding the bike the right way up

 

[Topdonkey]

That's your problem, try riding the bike the right way up

Lol must have been taken with an Australian camera !!

 

[Fordulike]

Didn't realise you had a full susser. More pivot points to wibble wobble lol

 

[awol]

View attachment 11412

You got 14s in that small crossbar frame bag? I struggled to get 12s in the one I got.
If so can you give us a link for it?

 

[Topdonkey]

14s in there with space to spare !, also fitted a rain cover, wallet, phone and lipo voltage checker too ! Its only 8ah of 14s in there, but i have another identical pack in my backpack for longer journeys, Its made up of the Turnigy Multistar lipo packs, 2 x 4s 8000mah and 1 x 6s 8000mah all wired in series to give the 14s

http://www.amazon.co.uk/gp/product/B002K7LC08?psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00

 

[fos'l]

My BBS02, no battery yet so it's not operational, has the right crankarm about 10-15 mm further away from the frame that the left. Long shot, but could this be related to your "wiggling"?