Bafang reliability (my experience - OVERWHLMINGLY POSITIVE!)

[Ghost1951]

I got progressively more brutal with the tightening of that nut, to the point where it hasn't needed tightening for over three years.

Maybe that is my problem. Way back in the 1960s and early 1970s, I had issues with my motorbikes of stripped threads and broken bits from over-tightening. Brutality led to numerous issues. I didn't hit it massively hard. I don't think the correct tool would easily tighten it enough. The leverage on the handle would tighten it way less than my hits with a three pound hammer on a well seated, blunt chisel in one of the notches..

 

[saneagle]

On the Bafang crank drive reliability thing, I had to curtail my planned ride with the GF this morning when my motor started creaking. I knew what it was pretty quickly after checking the tightness of the nearside pedal arm. That was fine and tightening it didn't improve the creaking noise. It was the big castellated nut that holds the Bafang motor in the bottom bracket. So, we shortened our ride and went back to her place where I re-tightened it with a hammer and blunt cold chisel. I managed to get a quarter turn on it with about six hits. Going nowhere now - for a while at least. Even done up tight, they don't stay tight for more than about 800 miles. This is the second time I have had to intervene with this. No biggie, as long as you have a decent sized hammer with you on the road....

You can always add a torque arm to resist the motor's torque rather than rely on the friction of that silly ring nut. You can use a 32mm spotlight bracket on the seat tube as an anchor point for the frame, and make a tiebar that fixes to any convenient motor screw or one of the two bracket fixing points. It's a 5 minute job and much more secure.

 

[guerney]

Maybe that is my problem. Way back in the 1960s and early 1970s, I had issues with my motorbikes of stripped threads and broken bits from over-tightening. Brutality led to numerous issues. I didn't hit it massively hard. I don't think the correct tool would easily tighten it enough. The leverage on the handle would tighten it way less than my hits with a three pound hammer on a well seated, blunt chisel in one of the notches..

I used a big hook wrench, no hammer, and it's the nut under the aluminium cover which needs tightening most - feels like it'd be easy to strip the thread on big but thin aluminium castellated nut/cover.

 

[Ghost1951]

I used a big adjustable spanner, no hammer, and it's the nut under the aluminium cover which needs tightening most - feels like it'd be easy to strip the thread on big but thin aluminium castellated nut .

I think that would strip easily. Big torque and alu threads don't go well together.

I am trying to visualise saneagle's solution. I need to think about it to get it clear in my head.

EDit: Right, I am beginning to see what he means. It is exactly what he said actually, spotlight bracket on seat tube and rod of some sort between that and motor screw. There are some screws on the bracket that resists the torque already - teh first one in this set.

 

[guerney]

think that would strip easily. Big torque and alu threads don't go well together.

The big aluminium thread on the motor can withstand the right amount of brutality. That pair of nuts work well in combination.

 

[saneagle]

I think that would strip easily. Big torque and alu threads don't go well together.

I am trying to visualise saneagle's solution. I need to think about it to get it clear in my head.

Photos in post #63.

New Project Started

I am confused now... are you going to use TSDZ2B and bike parts to make flat packed self assembling Ikea furniture?

www.pedelecs.co.uk

It would be a bit easier than mine on most bikes because you don't have to worry about the swinging arm for the rear suspension.

 

[guerney]

I think that would strip easily. Big torque and alu threads don't go well together.

I am trying to visualise saneagle's solution. I need to think about it to get it clear in my head.

EDit: Right, I am beginning to see what he means. It is exactly what he said actually, spotlight bracket on seat tube and rod of some sort between that and motor screw. There are some screws on the bracket that resists the torque already - teh first one in this set.

View attachment 58263

The middle nut in the pic is the one which needs tightening most, take it much easier with the one on the right. Use the Bafang tool or a hook wrench. You probably already know the raised bumpy side of the bracket on the left needs to be against the BB.

 

[Ghost1951]

The middle nut in the pic is the one which needs tightening most, take it much easier with the one on the right. Use the Bafang tool or a hook wrench. You probably already know the raised bumpy side of the bracket on the left needs to be against the BB.

Yeah - all of that well understood.

Saneagle's post linking to how he made his tongsheng torque arm makes all clear.

Wondering why he has different sized wheels on that project. Looks like a 1950s shop keeper's delivery bike, but powered.




Maybe the mystery is that he is making a powered version of this one.....

 

[guerney]

Maybe the mystery is that he is making a powered version of this one.....

It's a concentrated wind juice project. Tell no one.

 

[Az.]

Maybe threadlocker would help?

https://www.amazon.co.uk/Loctite-Threadlocker-Prevents-Leakage-Corrosion/dp/B07BP9JPC9/ref=sr_1_1?crid=HEQK8Z444IK&dib=eyJ2IjoiMSJ9.x96lQ6m1OfCIr6W8DXOyWBX03vEQjf5OwljF7UrIAe3AWhhxmgsiO-hm-h4BX6_Le6cu6kwVgEUv7i_I0b2uaqQT2trI2nalHFgSorfw846iyobjE3PPnptGxdXLv4yfeM-ySdlAUlEF-VwVfHvN-A.H_hhdp6yNqRCwAPbML-8YGagTY8-GVxLaPgmX_nUYhE&dib_tag=se&keywords=threadlock&qid=1705178427&s=amazon-devices&sprefix=threadlock%2Camazon-devices%2C197&sr=1-1&th=1

I wonder now if I was to gentle... I only wacked it few times with a piece of timber. Well... time will tell.

 

[Ghost1951]

Maybe threadlocker would help?

https://www.amazon.co.uk/Loctite-Threadlocker-Prevents-Leakage-Corrosion/dp/B07BP9JPC9/ref=sr_1_1?crid=HEQK8Z444IK&dib=eyJ2IjoiMSJ9.x96lQ6m1OfCIr6W8DXOyWBX03vEQjf5OwljF7UrIAe3AWhhxmgsiO-hm-h4BX6_Le6cu6kwVgEUv7i_I0b2uaqQT2trI2nalHFgSorfw846iyobjE3PPnptGxdXLv4yfeM-ySdlAUlEF-VwVfHvN-A.H_hhdp6yNqRCwAPbML-8YGagTY8-GVxLaPgmX_nUYhE&dib_tag=se&keywords=threadlock&qid=1705178427&s=amazon-devices&sprefix=threadlock%2Camazon-devices%2C197&sr=1-1&th=1

I wonder now if I was to gentle... I only wacked it few times with a piece of timber. Well... time will tell.

Threadlock - yes - good idea.

On the whacking with timber.... Ha ha - yes, I had a centre punch with me for directing the torque force to the castellated nut, when we decided to turn back, but no heavy tool I could have pressed into service as a hammer. I did think of borrowing a big stone from a dry stone wall, of which there are thousands of miles around here. Then I thought cave man techniques are probably incompatible with electrified bikes.... I mean .... That takes us to a new level of mechanical brutality, doesn't it.

 

[Nealh]

The Tsdz lock/ nut is much the same as the BBS, I use the C spanner and used a couple of whacks with a hammer to torque it up. Not creaked or come undone at all.

 

[Nealh]

I nip it up as tight by handa possible first with the C spanner then give it the hammer treatment, gives another good 1/4 to 1/2 turn.

Loving the tsdz far far better then the BBS01 I had.

 

[Saracen]

Open all hours Granville

 

[mr_ed]

On the Bafang crank drive reliability thing, I had to curtail my planned ride with the GF this morning when my motor started creaking. I knew what it was pretty quickly after checking the tightness of the nearside pedal arm. That was fine and tightening it didn't improve the creaking noise. It was the big castellated nut that holds the Bafang motor in the bottom bracket. So, we shortened our ride and went back to her place where I re-tightened it with a hammer and blunt cold chisel. I managed to get a quarter turn on it with about six hits. Going nowhere now - for a while at least. Even done up tight, they don't stay tight for more than about 800 miles. This is the second time I have had to intervene with this. No biggie, as long as you have a decent sized hammer with you on the road....

Buy the proper socket and do it up with a torque wrench? Mine hasn’t moved at all in 2000 miles and 18 months. I think the socket was about £30. I've lent it to a mate for him to do his too, if you’re local you can borrow it!

 

[Ghost1951]

Buy the proper socket and do it up with a torque wrench? Mine hasn’t moved at all in 2000 miles and 18 months. I think the socket was about £30. I've lent it to a mate for him to do his too, if you’re local you can borrow it!

A kind offer. Thanks, but I doubt we are anywhere near one another. I live in Northumberland.

 

[vantage]

You wanna be careful with tightening that nut. I recently had to rebuild my BBS02 because the bearings had been obliterated due to overtightening. Not something I'd wanna do again.

 

[Ghost1951]

You wanna be careful with tightening that nut. I recently had to rebuild my BBS02 because the bearings had been obliterated due to overtightening. Not something I'd wanna do again.
View attachment 58304

I can't quite see how the tension on that big castellated nut would affect the bearings... But then I never dismantled one so what do I know? How would that work?

 

[guerney]

I'm quite discomfited by the talk of hammers being used to tighten nuts. Tighten by hand, if it works loose, tighten more tight next time.

 

[guerney]

You wanna be careful with tightening that nut. I recently had to rebuild my BBS02 because the bearings had been obliterated due to overtightening.

How do you know for certain your balls weren't obliterated through overuse at high power? Did you tighten that nut using a hammer?