Rear disc brake snapped off, hub wired through frame

[russell]

I have had this bike for 2 years, for some reason whilst riding I applied my rear brake and the rear wheel jammed. On checking the rear wheel I discovered that 3 of the securing screws for the brake disc had disappeared, one has sheared off, as a consequence when I applied my brake and everything jammed.

So that I could get home, (I am a young 70 year old) all I could do was to take out the remaining screw and disconnect my caliper so that the brake disc was free to spin when the wheel turned.

2 of the lugs that the disc screw into are damaged, 1. has a screw snapped in it , the other has half of the lug snapped off.

I thought it would be a simple job of buying a new part that the disc screws into, and replace the disc, but alas life can be a B....r sometimes.

When I look at taking the rear wheel out its not possible as the hub wires go through the frame, the wheel is attached through the frame Not slotted, so I am stuffed and am begging for some help.PLEASE

I am not sure if this is the right forum so I will apologise if its not.

I have used this form soem time ago and cant speak highly enough of it so here's hoping..

 

[Alan Quay]

I think you should post some pictures, and tell us what make / model the bike is. I would very surprised to find a bike where rear wheel removal is not possible.

 

[jackhandy]

Should be fun changing a tyre on that bike

 

[russell]

I think you should post some pictures, and tell us what make / model the bike is. I would very surprised to find a bike where rear wheel removal is not possible.

So sorry chaps,, I was getting myself in a tizzy,, the wheel is in a slot and I can take it off BUT I still cant take the disc off because the hub wire goes from the hub through the disc to the controller,,, I will have to have a look at the controller to see if I am comfortable with disconnecting it to take the bent disc off, if I cant do it it's off to Halfords.

 

[Deleted member 4366]

Be careful about taking it to Halfords. They probably don't know anything useful about electric bikes like yours.

I had to repair one when they put normal disc screws in a hub motor, which ruined it. Electric bike disc screws are often shorter,

 

[Alan Quay]

If you want help, then please let us know what bike you have.

 

[russell]

If you want help, then please let us know what bike you have.

Sorry Mike for the confusion but things are much clearer now but unfortunately I have no idea what make it is. I bought it from a Chinese couple who have a 17 year old son. His Grandmother sent him the bike from China for his birthday, as you can imagine he wouldn't be seen dead on an electric bike so they sold it and gave him the money. It was still boxed when I collected it brand new.

I have now moved forward a bit in so far as I have traced the wire from the hub to the controller and disconnected all of the wires which then allowed me to slide the damaged disc off. I bought a replacement disc but surprisingly the holes did not line up to screw into the disc screw points on the hub. I have straightened out the bent disc pretty well. The damaged lugs still had a good amount of usable thread, I have drilled out successfully the screw that was snapped off inside the hub disc support.

Ideally if I can obtain a new disc support which I think simply screws into the hub then it would solve my problem. In the meantime I have replaced everything, reconnected and all is working ok other than the disc is touching slightly at one point.. Would you know what the part is called that I need to buy,,is it avaiable as a spare part,,, wh.
I expected the holes in the disc to be standard but maybe they are not.
I will upload some pictures although its all put back together now and I should have taken a picture whilst it was off.

 

[Deleted member 4366]

Without knowing what you've got, it's impossible to help.

 

[pdarnett]

Get some pictures of the part, it might be something that could be machined as a one off, if its not an off the shelf part.

 

[russell]

 

[Deleted member 4366]

It looks like a screw-on disc adaptor:
http://www.bicycledesigner.com/bike-parts/bicycle-brake/disc-brake-adapter---free-or-flip-flip-hub.html

http://www.scooterpart.net/product_info.php?products_id=1598

You'd need to take it offto check that it's an exact match. The disc looks standard. What was the disc that wouldn't fit?

 

[pdarnett]

It looks like one of these. http://www.bicycledesigner.com/bike-parts/bicycle-brake/disc-brake-adapter---free-or-flip-flip-hub.html or one of these? http://www.ebay.co.uk/itm/Brake-Disc-Rotor-Adaptor-flip-flop-left-handed-thread-/160655901577

 

[russell]

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It looks like a screw-on disc adaptor:
http://www.bicycledesigner.com/bike-parts/bicycle-brake/disc-brake-adapter---free-or-flip-flip-hub.html

http://www.scooterpart.net/product_info.php?products_id=1598

You'd need to take it offto check that it's an exact match. The disc looks standard. What was the disc that wouldn't fit?

Thank you all so much for your help and advise,,,,,I tried 2 different discs, one was brand new from Halfords, the other was off a discarded bike in Halfords workshop which they were kind enough to let me try but sadly again the holes didn't line up.

Although I cant tell now that I have put the wheel back together, I seem to think that the adaptor screws into the hub as apposed to on the hub but I cant be sure without taking it all off again which I will obviously need to do to measure it properly......

 

[russell]

It looks like one of these. http://www.bicycledesigner.com/bike-parts/bicycle-brake/disc-brake-adapter---free-or-flip-flip-hub.html or one of these? http://www.ebay.co.uk/itm/Brake-Disc-Rotor-Adaptor-flip-flop-left-handed-thread-/160655901577

Hello Paul, sorry I didn't reply sooner , been a bit unwell but I have tried to get the adaptor off but it wont budge,,, I'm a little worried it may snap and the if the one you suggest doesn't fit I am well in it... Would the adaptor be a normal thread that screws on clockwise... What dose free or flip flop mean.
There seems to be one or two of them around but I think most of them are for normal wheels without the electric hub.. I have sent an email to 3-4 sellers asking for the size of the centre hole but none have responded

 

[pdarnett]

The one you're trying to take off may have a left handed thread, i.e. it unscrews clockwise, you may have spent all day tightening it back up! Flip flop is a type of hub where you can have a sprocket either side. use by BMX'ers so they can flip the wheel over between events (unbolt the wheel( then have a larger sprocket for say a race rather than stunts.

 

[russell]

The one you're trying to take off may have a left handed thread, i.e. it unscrews clockwise, you may have spent all day tightening it back up! Flip flop is a type of hub where you can have a sprocket either side. use by BMX'ers so they can flip the wheel over between events (unbolt the wheel( then have a larger sprocket for say a race rather than stunts.

well chaps I have managed to find the correct adaptor off Ebay, a chap offered 2 brand new adaptors complete with disc attached. He did actually list them saying they were not standard screw positions, 140mm and the adaptor thread was perfect. I decided to get stuck in and try to take offe the damaged adaptor. I was a little nervous about disconnecting the hub from the controller but found it straight forward also the adaptor uncrewed easily... JOB DONE. Now I have one small problem, my crank sounded a little gritty. I dont have a puller so went to Halford to have new bottom plate, after they had fitted it I realised on the way home that the electrics would only come on with the throttle and that the pedal sensor wasn't working. I have had a quick look and the sensor disc just spins when I push it with my finger , it isn't attached to the chain wheel cog or whatever its called. Can someone advise how this is fitted or does mean I have to go back to Halfords. I am happy to fix it myself when I know how.

Thanks

 

[Cyclezee]

Hi Russell,

It sounds like the the plastic disc is not gripping the square taper of the bottom bracket and it needs to pushed closer to the sensor that picks up the rotation or it has has been fitted the wrong way round?

 

[Deleted member 4366]

Could you show us a photo from underneath, edge-ways on to the disc. There may be other problems.

 

[russell]

Could you show us a photo from underneath, edge-ways on to the disc. There may be other problems.

I have sorted it myself thank you.
I found a puller in my garage that I bought a couple of years ago .
The plastic sensor disc centre hole which is surrounded by tiny teeth which have been cut into the plastic. The disc simply pushes onto the spindle and I think that Halfords possibly loosened it when they took the chain crank off, then when replacing everything packed loads of grease in and around the crank which made the sensor very loose. I have cleaned everything up and also put 2 turns of tape around the spindle whare the sensor sits.
It has all gone very well and I am thankfully up and running again but for future reference where would I be able to obtain a new sensor disc..should the need arise..... thank you