Wheel keeps falling off!

Drake-601

Pedelecer
May 13, 2018
34
5
52
Greater Manchester
Hi, I hope someone can help.

I came onto this forum a few month ago as I was having power loss issues with my Kudos Tornado. I got some fantastic support on here, which identified the problem with a broken wire leading to the mag disk. I got that delivered and my local bike fella managed to fit it BUT, not without lots of struggle getting the back wheel back on. Most of this struggles - and I was there for the whole 1-hour 45-minutes, was getting the connecting threat back on; a think connecting tune with a fine thread.

In fareness to him he could "feel" that it wasn't going back in on occasions; kept unscrewing it and only tightened it up again when he felt that he wasn't going to create a 'cross thread' issue. Wheel back on, the bike ran really well for a couple of months.

Fast-forward to the last week...

My rear wheel detached and I took it back to him. He tighten it up BUT, I pointed out to him, there appeared to have been a twisting action that started to loosen the wire (with a coil-srpring around), in my opinion, leading to the wheel (sorry for the low-tech description). He told me not to worry and the bike worked fine the next trip out. However, the exect same thing happened the next journey out and, this time, I told him that I suspected an underlying issue and left it with him for a full week. All he did? was to tighten up the left-side bolt again and I got 10-feet away form the shop before it became detached again! This time, I noted further, the wire on the right-side looked even MORE damaged / twisted.

SO...he's suggested that I get a whole, new back wheel if one is available from a supplier for a Kudos Tornado. I do have a site that I got my mag disk from who were great last time but it's now Friday evening and, so, I might not be able to contact them until tomorrow or Monday morning.

In the meantime...HELP! Does anyone know why my rear bike wheel might be doing this? I know this sounds like a basic mechanical issue rather than an e-bike issue but I'm now worried that it's done damage to the right-side wire attachment and although I'm willing to taking my bike to Halfords for them to see why the wheel keeps detaching I know for a fact that they will not deal with e-bike issues.

I've had it for 2 years and both love and depend on it for so much. Do I need I new e-bike, I'm asking myself?

I contacted Cycle Republic in Manchester about the last issue before 'my fella' fixed it and they not only did not want to know but also were very rude and said, "...this is the problem with getting a foreign bike; we only deal with UK bike and only ones bought from us".

Any advice would be greatfully received once again...
 

Woosh

Trade Member
May 19, 2012
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I would suggest you post some pictures of the dropout area.
 
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Drake-601

Pedelecer
May 13, 2018
34
5
52
Greater Manchester
I would suggest you post some pictures of the dropout area.
Thanks for getting back to me, Woosh. Problem is, at the mo, my mobile phone also died the other week (aaaarrgh!) and I'm currently using one from the dark ages with no photo ability! My new phone is due to arrive on Tuesday and, from that point, I would be able to do so...I would hope. :(

Thank you again for the reply.
 

Woosh

Trade Member
May 19, 2012
19,476
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Southend on Sea
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the motor axle generates a lot of torque, you want to look for signs of damage to the sides of the dropout. The more permanent fix is to install torque arms on both sides of the motor axle.

This one is a small torque arm:

 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Hub wheels usually have a anti rotation washer on each side of the axle, said washer has a right angle tab that sits in the frames drop out to hold the wheel in position.
Also most bikes have at least one torque arm to prevent axle rotation this goes on before the axle nut.

Ideally some pics of your axle with nuts and washers may help.
If he wheel/axle twists out of the axle to much you will stand a good chance of damaging the motor wire and shorting them, if this occurs then you will need a new hub as repair isn't easy.
 
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Drake-601

Pedelecer
May 13, 2018
34
5
52
Greater Manchester
the motor axle generates a lot of torque, you want to look for signs of damage to the sides of the dropout. The more permanent fix is to install torque arms on both sides of the motor axle.

This one is a small torque arm:

Hi Woosh & Nealh, what you have both said now make so much sense in my head and I kept telling my bike fell that I though the issue was twisting the wire that comes out of the hub! He wouldn't listen and offered none of the advice you have both suggested. Sadly, I think there has been some damage to this wire now. Huhhhhhh...

I think what I will do is get the bike back from the shop today and use my wife's phone to take photos and send them to you both soon for you to have a look / confirm my fears.

Should it be salvageable, I think investing in these torque arms is a very good idea...but I think I'll take it to a different shop for them to fit. Is this something Halfords could fit, would you say / advise? I'm losing faith again in my local shop fella who, with basic stuff seems fine but not so when messing around with the hub area of an e-bike.

Althernative would be to try and find a replacement wheel hub for a Kudos bike that is no longer in production, which I can imagine is very expensive.
 

Drake-601

Pedelecer
May 13, 2018
34
5
52
Greater Manchester
Hub wheels usually have a anti rotation washer on each side of the axle, said washer has a right angle tab that sits in the frames drop out to hold the wheel in position.
Also most bikes have at least one torque arm to prevent axle rotation this goes on before the axle nut.

Ideally some pics of your axle with nuts and washers may help.
If he wheel/axle twists out of the axle to much you will stand a good chance of damaging the motor wire and shorting them, if this occurs then you will need a new hub as repair isn't easy.
Hi Woosh & Nealh, what you have both said now make so much sense in my head and I kept telling my bike fell that I though the issue was twisting the wire that comes out of the hub! He wouldn't listen and offered none of the advice you have both suggested. Sadly, I think there has been some damage to this wire now. Huhhhhhh...

I think what I will do is get the bike back from the shop today and use my wife's phone to take photos and send them to you both soon for you to have a look / confirm my fears.

Should it be salvageable, I think investing in these torque arms is a very good idea...but I think I'll take it to a different shop for them to fit. Is this something Halfords could fit, would you say / advise? I'm losing faith again in my local shop fella who, with basic stuff seems fine but not so when messing around with the hub area of an e-bike.

Althernative would be to try and find a replacement wheel hub for a Kudos bike that is no longer in production, which I can imagine is very expensive.
 

Woosh

Trade Member
May 19, 2012
19,476
16,423
Southend on Sea
wooshbikes.co.uk
I can repair broken motor cable for you if the cable has been cut.
may be a cheaper option?
 

JPGiant

Esteemed Pedelecer
Sep 3, 2017
364
167
West Yorkshire
Read this... http://www.ebikeschool.com/install-hub-motor-washers/ ... to understand the nut/washer arrangement.
Check the drop-outs for damage and/or cracks, do some research into torque arms and if you need them.
If the cable is damaged, contact Woosh and take up his offer to repair it. Simples.
Don't deal with numpties or idiotic bike shops - if the bike means that much to you get it sorted by the right people.
 
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Drake-601

Pedelecer
May 13, 2018
34
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Greater Manchester
Read this... http://www.ebikeschool.com/install-hub-motor-washers/ ... to understand the nut/washer arrangement.
Check the drop-outs for damage and/or cracks, do some research into torque arms and if you need them.
If the cable is damaged, contact Woosh and take up his offer to repair it. Simples.
Don't deal with numpties or idiotic bike shops - if the bike means that much to you get it sorted by the right people.
Hi JP.

Thank you so much for your reply and, indeed, for the link too!

I am gonna get the bike back in the next hour and intend to both look at that area as well as take some photos to upload; taking it from there with my decision making.

Yes, I agree; my local fella who's been set up near me for about a year now seems fine with replacing brake & gear cables etc. and although he TOLD me he has experience at dealing with rear hub issues on e-bikes my instincts tell me otherwise. However, Halfords (about 2 miles from me) often roll their eyes whenever I take it in for whatever reason and they have to 'deal with' issues around the rear wheel; a shop in Manchester called Cycle Republic just don't want to know if it wasn't a bike purchased from them (and were quite rude on the phone :mad:) and...that's basically it near me! I don't drive and have limited access to my wife's car (when she's available) and, so, I have come to rely on my local fella more and more for good...and not so. :(

Onwards & upwards though - with all of your advice at least I now have more of an understanding of the issue, what to look at closely and what solutions might be available to me before looking into an entire new wheel hub replacement.

I would love to take up Woosh's kind offer, should that be needed but, as I've replied to him, he's in Southend-on-Sea and I'm on the outskirts of Manchester... :rolleyes:

Thanks again!
 

Artstu

Esteemed Pedelecer
Aug 2, 2009
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It sounds terminal, hopefully the photos will prove me wrong.

web photo


on the plus side part of the drop out including the rear hanger is at least replaceable
 
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Nealh

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Sadly most LBS haven't a clue about e bike hub fitment all they do is sell bikes and repair non e bikes. They don't understand the torque element/force that the hub rotation applies to the drop outs, the case of just tightening nuts extra tight is not the answer as in the end all that will happen is nut threading will be stripped which may have already occurred.
Ideally you need a local diy e bike builder or a proper/reputable ebike independent dealer, taking problem to Halfords or Evans in my view is a waste of time.

As regard to repair if indeed the cable is broken or compromised the cheapest option is to remove motor wheel and send it to Woosh for repair.
Removing tyre and tube first will make it lighter and less bulky to package up though weight will still be 6 - 7kg.
 

Nealh

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As for pics Drake a nice clear one from each side esp paying attention to the condition/state of the drop outs.
Also a pic of the order the axle fittings are in, no need to remove the wheel just undo the axle fittings from each side.
The pics Artstu has given looks as if torque arms aren't used.
 

Drake-601

Pedelecer
May 13, 2018
34
5
52
Greater Manchester
Sadly most LBS haven't a clue about e bike hub fitment all they do is sell bikes and repair non e bikes. They don't understand the torque element/force that the hub rotation applies to the drop outs, the case of just tightening nuts extra tight is not the answer as in the end all that will happen is nut threading will be stripped which may have already occurred.
Ideally you need a local diy e bike builder or a proper/reputable ebike independent dealer, taking problem to Halfords or Evans in my view is a waste of time.

As regard to repair if indeed the cable is broken or compromised the cheapest option is to remove motor wheel and send it to Woosh for repair.
Removing tyre and tube first will make it lighter and less bulky to package up though weight will still be 6 - 7kg.
Fab advice and, as always, makes clear sense. I'm about to upload some pics but suspect someone is gonna say, "Yep...that's been (insert bad word) up by a local bike shop not knowing what they're doing with e-bike hubs".

I wasn't aware you could post / package the hub to Woosh so thanks for that info, Nealh. That's good to know and might be needed although to then get the wheel back on properly for an e-bike still leaves me with the issue of not having a local diy e-bike builder neat me (without more research of course).

Much appreciate the advice as always!Pic 1 - Left side.jpg Pic 1 - Left side.jpg Pic 1 - Left side.jpg Pic 2 - Right side with wire.jpg Pic 3 - Right side with wire.jpg Pic 1 - Left side.jpg Pic 2 - Right side with wire.jpg Pic 3 - Right side with wire.jpg Pic 4 - Left side.jpg
 

wheeliepete

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Feb 28, 2016
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You are deff. suffering axle rotation and it does not appear in your photos there are any anti-rotation washers fitted on either side of the bike. Even if they are, they are not doing their job. Your axle needs to be rotated at least 200 degrees clockwise to untwist the motor cable and a torque arm fitted. I would advise one each side as your dropouts have been damaged. Contact the shop in JP's link if it is local to you and see if they can help fit them.

https://www.ebay.co.uk/i/113059111450
 
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Nealh

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Example of anti rotation washer Drake.
Your axle should have one on each side, most likely you would need 12 x 10mm but you need to measure your axle to check.
https://www.ebay.co.uk/itm/2x-Electric-Bike-Hub-Motor-Axle-Torque-Anti-Rotation-Washer-10x14mm-4mm-thick-/282054303673

Often it is not easy to fix a torque arm one on the drive side and often one is only needed on the brake/non drive side.
In your pic of the brake side there is a tapped hole and I wonder if a T/A was fitted previously just as in Woosh's pic in #4.
You can make a torque arm out of any piece of good 2 or 3 mm steel, drill a 10 mm hole then carefully file out the shape (patience needed) to fit over the axle snuggly, then drill out a 6mm hole to line up with the tapped hole. Finally shape the metal to suit the bike drop out.
 
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Nealh

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Be very careful with the motor wire, although it is badly twisted it may still be intact. It might be prudent to detach the cable at the joint along the rear stay and then carefully untwist it if it doesn't do it by it self.
 
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