My cursed TSDZ2...

[not dave]

So after having my crank fall off and my charger failing there appears to be another problem.
The cranks will now only turn with a massive amino if force and won’t back pedal. The throttle will get the back wheel moving but there seems to be some extra noise from the motor.
Could this be a serious motor problem?

 

[peter.c]

Ouch take the chain off and check for the noise if so sounds like a replacement required
now getting worried

 

[not dave]

Definitely wasn’t a chain noise.
Alice at pswpower is going to love me. It took half a dozen mails to get them to replace the charger. The only thing that hasn’t been faulty is the display and battery.
which one of them is going to go next!

 

[vfr400]

Definitely wasn’t a chain noise.
Alice at pswpower is going to love me. It took half a dozen mails to get them to replace the charger. The only thing that hasn’t been faulty is the display and battery.
which one of them is going to go next!

I hope you were polite and patient with those emails. Dis they ask you to check the fuse or anything like that. The Chinese are sympathetic and helpful up to a point. if you cross that point, you'll get stone-walled. The problem that you have is that it's possible to rip the gear or blow the controller by misuse, like messed up gear change, wrong gear, pedalling too slow, chain came off, etc. PSWPower are going to be suspicious, especially when you had a previous complaint.

The quickest and most efficient solution would be to open the motor to confirm what's wrong.

You have stated what the problem is without saying how it came about. Problems never happen for nothing. How they happened is a good clue as to what is wrong.

 

[not dave]

I always try to be professional and courteous and acted so in my mails with pswpower.
the bike has not been used in about two weeks due to the problem with the crank. I replaced the crank today and noticed the problem while replacing. The last journey was around 10 miles or so, no steep hills or any mechanical problems.
Note that the motor is still working with the throttle, but is very stiff to pedal and won’t back pedal.

 

[vfr400]

I always try to be professional and courteous and acted so in my mails with pswpower.
the bike has not been used in about two weeks due to the problem with the crank. I replaced the crank today and noticed the problem while replacing. The last journey was around 10 miles or so, no steep hills or any mechanical problems.
Note that the motor is still working with the throttle, but is very stiff to pedal and won’t back pedal.

I'm trying to make sense of that. Tell me if this is right.

Your bike was working properly. You took the crank off (left, right or both sides?) And after you put it back, the motor had this problem.

I can almost guarantee that you won't get any help from China as it stands. The best you can do is find out what's wrong. If you damaged something when you tightened the crank bolts by tightening against the motor instead of the crank arm, you might have a chance of them sending you a free replacement part.

As I said before, you have to find out for yourself what's wrong unless you want to take the drive unit back off and use it as a boat anchor.

 

[Gavin]

but is very stiff to pedal and won’t back pedal.

I notice from your other thread a while back (here)....

TSDZ2 Crank fell off - what spec for replacement nut?

Riding home last night my crank arm fell off... Obviously i didn't fit it correctly when fitting my TSDZ2 motor. Is the nut that holds the crank a standard size? Need to hunt round the local bike shops but dont know what the size or thread i need to ask for. PS, its the left crank if that makes...

www.pedelecs.co.uk

....that it was the left-hand crank that fell off. When you tightened it up, how did you stop the motor rotating when you did it back up? You'd have been tightening it clockwise on the LHS (i.e. in a back-pedal direction), so I'm wondering if you somehow damaged the sprag clutch whilst doing it up.

If you've got a throttle (or walk assist on VLCD5) take the chain off and just run the motor as a "bench test". You might find the noise tells you something....

 

[vfr400]

What's the normal clearance between the inner face of the crank arm and the BB. Is it possible that in his attempt to get it tight, he's pulled it so far up the taper that the inner face is rubbing. If you ride with a loose crank, you change the flat taper shape to a curved one, so the next time you tighten it, it goes further up the taper. This one looks quite close:

 

[vfr400]

Dave not dave or whoever you are, look at the gap between the inner face of the crank arm and the bottom bracket, Tell us how big it is or, better still, show us a photo.

 

[Gavin]

What's the normal clearance between the inner face of the crank arm and the BB

Interesting thought here VFR although it doesn't explain why the resistance is greater rotating backwards than fowards.

I hadn't clocked how tight the clearance is though. I just measured mine out of curiosity: 1.15mm clearance

 

[vfr400]

Interesting thought here VFR although it doesn't explain why the resistance is greater rotating backwards than fowards.

I hadn't clocked how tight the clearance is though. I just measured mine out of curiosity: 1.15mm clearance

That's not that much. I've seen that sort of distance disappear, just by taking off the crank and putting it back on. That's really annoying when you have a PAS magnet disc. I've had to grind some off the back of the crank face several times on various bikes because of that.

We'll see when we get the photo, but OP doesn't seem to be in any hurry to sort it.

 

[JohnDaBike]

Interesting thought here VFR although it doesn't explain why the resistance is greater rotating backwards than fowards.

I hadn't clocked how tight the clearance is though. I just measured mine out of curiosity: 1.15mm clearance

Yup, I have about the same 1 to 1.5mm

 

[not dave]

Thanks all. I’m away for the weekend but will take a closer look at the left crank clearance. That does sound like a possibility.

 

[not dave]

So it seemed like it was user error...

Removed the crank bolt, the cranks still wouldn't turn. Slowly removed the left crank off the spindle and the cranks would turn with some obvious friction. Removed the crank a little more off the spindle and the cranks now turn freely.
So all is now well and the crank and crank bolt are fitted and turning freely.

But... what is to stop the crank slipping further down the spindle and causing similar problems?

This is the crank that i bought off amazon.
Some pictures of my bike with the crank fitted

 

[wheeliepete]

It's good to mention when you fit parts that were not part of the original kit. What have you done to stop the crank arm binding? Left the bolt loose? Wasn't your original problem losing the bolt?

 

[vfr400]

You can't ride your bike with loose cranks. Take them off and grind/file about 3mm off the inside face so that you can tighten them without them rubbing on anything.

 

[peter.c]

The taper on the tsdz2 cranks is not the same between batches yet alone fitting a after market crank
ALWAYS USE LOCTITE THEY FALL OFF IF NOT CHECKED BEFORE USE [design problem still on the 2020 model]

A custom crank chain spider removed to fit as need more clearance on the other side The grinder on the inside will help go to far and it will not tighten

 

[not dave]

It's good to mention when you fit parts that were not part of the original kit. What have you done to stop the crank arm binding? Left the bolt loose? Wasn't your original problem losing the bolt?

'Crank arm binding'. Its good to know the terms to describe the problem.

I, in my ignorance assumed that a crank was a crank, so have simply removed the old one and refitted the new assuming things would be fine. I have learnt that it is not that simple...

Visually inspecting the two cranks, the new one appears to be a few mm wider than the old one which seems to be causing the problem.

I dont have a grinder though could get a file from Screwfix, would something like this do?

File Set 8

Order online at Screwfix.com. File set consisting of flat, round and half-round files. Suitable for various applications. FREE next day delivery available, free collection in 5 minutes.

www.screwfix.com

I assume the crank is aluminium so should be able to use a hand file?

PS, many thanks for everybody's patience with this mechanical moron!

 

[vfr400]

One of these will be much quicker:

VOCHE® MINI ROTARY HOBBY DRILL COMBI MULTI GRINDER TOOL KIT + 260PC ACCESSORIES 3172663193072 | eBay

This highly versatile Rotary Drill Multi Tool Kit would be a great addition to any DIY fanatic or hobbists toolbox. It works on a high speed, low torque principle where the revolution can attain 30,000rpm compared to a typical 2,800rpm for a standard electric drill.

www.ebay.co.uk

 

[not dave]

One of these will be much quicker:

VOCHE® MINI ROTARY HOBBY DRILL COMBI MULTI GRINDER TOOL KIT + 260PC ACCESSORIES 3172663193072 | eBay

This highly versatile Rotary Drill Multi Tool Kit would be a great addition to any DIY fanatic or hobbists toolbox. It works on a high speed, low torque principle where the revolution can attain 30,000rpm compared to a typical 2,800rpm for a standard electric drill.

www.ebay.co.uk

Ahhh!

Ive got an unused Dremel tucked away in a corner of the garage! Bought about five years ago and forgotten about.
Thanks for the suggestion