Rear wheel puncture

[103Alex1]

They are Schrader valves. Regarding the dropout, I can't remember if it was downwards or not but there was at least an inch available to slide it backwards and forwards. No derailleur, just a freewheel on the side of the hub.

I will definitely get this sorted after the weekend. I will try and do the tube as well following your advice.

Good stuff and good luck. Yes, you have horizontal dropouts just like my Agattu. Exactly the same issues by the sounds of it with the wheel alignment (and in my case slip too) that plagued me for weeks trying to work out what it was and what to do about it. You just need new washers between axle nut and dropout. I'd be very surprised if that doesn't sort it for you.

Make sure your chain's decently tight when you do up the axle nuts too. Sometimes there's masses of play in the dropout opposite the chain side (there is on mine) and when you tighten that opposite side the chain slackens on the chain side. The secret is to do both axle nuts up evenly and if necessary just pull the wheel towards you a bit when doing up the freewheel side until the washer threads engage the frame at the right point when it's just held on the other side. Then tighten the non-drive side with all the play in it.

If your wheel won't stay aligned or slips after that there is a fix to retain the axle in place with an additional fitting that people sometimes use if they have these issues with horizontal dropouts. d8veh knows how to do it .

 

[Synthman]

I don't even think there were any washers between the nut and the dropout. It is about 2 years since I last had the back end apart. Where would I be able to obtain the washers from?

I would also be interested in hearing what this 'fix' to keep the axle in place if the nuts fail to do so. Also if there is a damaged thread on the axle is it likely to be a huge problem to repair?

I'm more worried about the servo brake though. Although I did have a bad habit of using mostly rear brake when it worked, I can't believe it would be worn down with less than 5000 miles. The front brakes weren't, just the shoe had cracked. I found out the Suzuki FS50 has the same front brakes and it was an easy fix.

I've had another look at the pictures a member posted in http://www.pedelecs.co.uk/forum/electric-bicycles/13507-servo-brake.html and I cannot understand how the thing is held together at all. I think the left side of the cover attaches to the bike frame, mine has a couple of bolts and a lot of rust holding it. Is it even possible to get the cover off without having to release the wheel first? I also don't understand how it stops the wheel. Is the brake 'hub' mounted to the side of the motor, and the brake shoes are mounted in the 'cover' of the servo brake?

If the shoes are damaged I'm not entirely certain I could find a suitable replacement. This is why I hope there is a way of inspecting it without removing the wheel. I want to make sure I have all the parts available first.

 

[103Alex1]

Washers go between the axle nut and the dropout, and have a 'lip' which slots in to the dropout opening from outside in. They have a slightly 'toothed' surface which grips the frame.

Looking at the photos on that thread it doesn't seem that the manufacturer chose to use them and so I am not at all surprised you might have problems seating the wheel.

If you want I can send you my worn washers to try for size - at least you'd know whether they fitted the axle and dropout - and could see if they were any help before ordering any.

So far as I understand it, the solution to slipping wheels is pretty similar to a torque arm. Face plate slots over the axle and retaining arm part gets fixed to the frame. If they're a single piece they'd need to be made up to size. Otherwise you could try just fitting a pair of torque arms to the back wheel which would basically do the same thing. They're not needed for anti-rotation against a powerful motor so the old style ones which you just fix to the stays with a metal ring would probably do the trick.

They look like this :

EBike Torque Arm

Forum members have spares if you ask about.

I can't help on the servo brake I'm afraid. Wurly should know.

Edit :- see photo of washers alongside a torque arm.

The washers slot over the axle before the wheel nut is put on. The protruding part of the washers slots in the dropout and the remainder grips the frame, under tension from the axle nut that's tightened up against them.

These washers are off my hub gear axle and by the looks of it this is smaller in cross section than a hub motor axle (see holes as compared to the torque arm, which is for a hub motor axle). So likelihood is these particular washers won't fit your axle. You can get them for larger axles but they may not work well for reinforcing wheel retention in horizontal dropouts unless the area of your frame around the dropouts is suitable for the toothed side to grip. The ones I've seen have a rough area in that region to help the washers grip the frame.

 

[Synthman]

I didn't get round to sorting it. I had some issues today with the method of pumping up the wheel before every trip. There was massive resistance in the pump pedal. I tried a handheld pump and the same thing happened. I concluded that the tube had another problem and tried to go to my LBS to get a new tube. I didn't think they would be open on Easter sunday, and they weren't. The road was cordoned off and it turns out the LBS burnt down completely this morning. Luckily there is another shop a bit further away but I had to make a massive detour round the cordon to get to it. When I got the tube home I tried to inflate it slightly ready for fitting, and had the same issue with the pumps. I had to go back to the shop and get a new adapter and that fixed it.

I had a short journey to make so I did that first before attempting the repair. When I got home I started taking the bike apart and failed at the first step. I couldn't get the wheel off! I undid the two nuts, removed the torque washer and the centre stand but the wheel wouldn't slide out.

It looks like the rear brake cover is holding it back. The two bolts that secure this cover to the frame are completely corroded, and also the cover itself. I wonder how the hell the shop managed to change the tube last time, as it looks like no attempt was made to remove the brake.

Would there be another way of doing it, like trying to tap the axle to one side enough to allow me to remove the spacer washers hopefully leaving enough room to move the wheel sideways and out of the brake hub?

By the way, I reassembled the bike after this failed attempt. I had no trouble centering the wheel in the dropout but there is indeed an issue with the left hand nut. It looks like the axle thread is damaged and it won't tighten fully. I actually removed it by hand when removing the wheel.