[Thomas]

Thank you both for your help. I tested the situation at two positions of the frame stop. At the present regular position where the slot is beaten and at the extreme end which is looking fine. And indeed, s sleeve or a reducer is necessary. I'll go for a reducer of 3mm thickness welded to the inner drum. That will last better and is easier to produce. I did not expect that the play at this point is so crucial. As soon as the reducer is installed I will give an update. Again, many thanks and cheers, Thomas 

[singleminded]

You could get someone to weld a little metal to each side of the slot and then file it back to be a snug fit on the anchor peg/bolt. If you fit a sleeve to the anchor point you would still have to file the slot in the brake plate out otherwise you would not be able to adjust the chain tension.Not having tried the amount of play on a bike with a good brake plate how much is too much play will be up to what you feel is acceptable.John

[kbryt]

you will have to sort out a way to put an external sleeve on the frame stop, or a reducer in the slot.
Just one of the joys of owning an obselete bike.

It exercises the brain.

[Thomas]

Hi Johne!
My description was not specific enough. Sorry for the confusion. With snapping (or may be clanking/jumping) I mean the tendency that the wheel does react on the brake pedal only after jumping over a small play in rotation. And it does that only in driving reaction The three hub bolts are tight. Meanwhile I probably know what you mean with splines It seems that I don't have splines (see attached pics). Correct? 

I also checked the anchor bolt at the frame. The next two pictures show it. It looks as if the anchor is somewhat flattened and the elongated hole in the plate is worn on one side. After your comment about the anchor I opened everything. A loose anchor would match with the wheel movement when the brake is enagaged. The chainguard is definitely not the problem because I still have the problem even when the chain is diconnected. Hence, it indeed looks as if the anchor is the problem.

I now wonder how to solve this trouble. The bolt is welded to the frame and a new plate is not available. In addition, because the bolt should be able to move within the hole there must always be some play. What can I do? Ideas are very welcome.
Cheers, Thomas

[singleminded]

just looked at your video again with the sound turned up high( i'm getting a bit deaf these days). It appears that there IS slack in the brake anchor..Now on the earlier bikes the boss for the brake cam passes through a slot in the frame and that is your anchor. most other makes of bike have a bar that bolts to the drum and the frame to stop the brake backplate from turning..It looks like you have a fully enclosed chainguard and the problem could be inside the guard..John

[singleminded]

I'm having trouble understanding what you mean by 'snapping'. Snapping to me is breaking or do you mean grabbing like' the brake snaps on'.
I notice there appears to be some movement of the drum when the brake is locked as if the brake anchor is loose..When loose splines are talked of on my bike, it would refer to the rear qd wheel which has splines in the drum and splines on the hub being worn. if the hub bolts are tight then this is not an issue, but I'm not sure if your bike has splines on the hub..John

[Thomas]

Sorry again but I am lost and don't understand what you're talking about. 

[kbryt]

If not splines then slack on the hub/drum studs

I take it the brake is not locked on?

[Thomas]

Sorry, which splines? I don't understand.

[kbryt]

sounds like slack in the splines to me.

[Thomas]

Hi all! My rear brake snaps when applying (see clip). I dismantled the wheel and the chaincase but can't find out what's going on. Can somebody tell me what it is?