Problem with my Bafang HD

Hixyhicks

Pedelecer
May 14, 2020
115
8
52
I am having an issue with my HD and want to strip it down. I thought it was the clutch but replaced and still have the same problem ,I an looking for the tool that allows me to remove the main spindle .I believe there are 2 locking nuts holding it in place . What's happening is when i change gear the motor makes a really bad mechanical noise .It sounds like the bike is struggling to find a gear but its not, like its slipping so I'm thinking one of the gears is knackered .Maybe the nylon gear ? when I removed the casing to replace the clutch the spindle moves in and out about an inch is that normal ? Could you tell me what tool I need to remove the locking nuts on the spindle please .Is it worth changing the nylon gear to a steel version .


Thanks in advance

Mick
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,692
1,465
Tyne and Wear
I use a pair of long needle nose pliers with small tips, which fits nicely into the slots of the locking nuts. When you fit them again, make sure you tighten just enough to take the play out of the spindle/axle and preferably use a light to medium strength threadlocker fluid. If you tighten too much, you are at risk of destroying the thrust bearings. Believe me, I know :(
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,711
3,458
Basildon
I am having an issue with my HD and want to strip it down. I thought it was the clutch but replaced and still have the same problem ,I an looking for the tool that allows me to remove the main spindle .I believe there are 2 locking nuts holding it in place . What's happening is when i change gear the motor makes a really bad mechanical noise .It sounds like the bike is struggling to find a gear but its not, like its slipping so I'm thinking one of the gears is knackered .Maybe the nylon gear ? when I removed the casing to replace the clutch the spindle moves in and out about an inch is that normal ? Could you tell me what tool I need to remove the locking nuts on the spindle please .Is it worth changing the nylon gear to a steel version .


Thanks in advance

Mick
Check out the motor connectors in the controller compartment. a loose one would give the symptoms you describe, and so would a dodgy mosfet, so it would be worth testing them while you have the cover off.

It's probably also a good idea to make sure that the phase wires aren't nickeds where they come through the casing. You have to remove the caulking for that, then reseal with high temperature silicone sealant.
 
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Hixyhicks

Pedelecer
May 14, 2020
115
8
52
Im ok with a soldering iron are replacing the mosfets easy to do. I have read the ones that come from the factory aint great.Is it worth changing them whilst im in there ?
 

Hixyhicks

Pedelecer
May 14, 2020
115
8
52
Can they be tested in the controller via the cables or do i need to remove the potting compound
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
8,711
3,458
Basildon
Not yet ,I'm trying to think ahead i need the bike I'm guessing there not an expensive part .
It's not easy to replace them. most people would buy a new controller, but you shouldn't do anything until you've tested to find out what's wrong. If it's a nicked wire, it takes 2 minutes to fix and costs about 2p.
 
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Hixyhicks

Pedelecer
May 14, 2020
115
8
52
Ok i forgot to mention when the bike is on a stand and im cycling through the gears it works fine. My problem is when i sit on the bike and put pressure through the peddles thats when i have problems .Thats what made me feel like it was the clutch. I will strip it down and have a look this weekend .
 

Hixyhicks

Pedelecer
May 14, 2020
115
8
52
ive stripped down the motor and checked the nylon gear which all looks good .The 3 main cables have nicks in the sheathing,im hoping that one of them is giving me my problems.If its not it is either the controller or maybe the gear the clutch sits in .I may have caused the cable issues when i was taking it apart . I'm a bit rough ,just like my misses says Ha .
 

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mxer

Pedelecer
Nov 28, 2010
92
10
That sticky out bit in the blue wire doesn't look good (also slightly burnt/ short) definitely could be your issue and looks factory, the others yes does look like may have been caused taking apart.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,692
1,465
Tyne and Wear
All looks fine. I have to agree with mxer, that the inner wire sticking out of the blue sheath isn't good, even if you find out it's not the cause of the original problem.
 

Hixyhicks

Pedelecer
May 14, 2020
115
8
52
I didnt have time to put the motor back together yesterday but will saturday .Then test it .If the controller is broken.Is removing the potting a viable option to make repairs ?I would rather repair Than by a new one .Ideally make the controller better with better grade parts .
 

peter.c

Esteemed Pedelecer
Apr 24, 2018
1,289
367
thurrock essex
The potting on my 750watt controller defeated me :mad: silicon cement like rubber and in a confined space with surface mount electronics versus shaky hands and the need of a magnifier glass
Ended up at Green bike kit and a replacement
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
13,120
5,111
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West Sx RH
Problem with the potting is it adheres to all the small tiny surface mount diodes, these are easily damaged by trying to lift the potting.
 

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