rear brake skim

[george747]

Does anybody know of someone near Coventry with one of those rear brake skimming tool thingys,getting very desperate trying to stop............Thanks

[shane BBoys]

How do?
There was a post not long ago, from Covboy, some time before Xmas.
Hope this helps.
Cheers Shane.

[george747]

Thanks,mabye he will see the post.

[rossclark]

Here

viewtopic.php?f=10&t=4500

[Covboy]

Jon at Gransport fixed it for me
3 main problems contributing to the issue
Rear brake cable routed incorrectly (over carb manifold, outer not fitting properly )
Very hard Italian shoes. Softer compound shoes fitted
SIL casing pivots misaligned. Rewelded to provide correct pivot profile

Now called scooter collective I think but trading from same Birmingham shop

[MK Monty]

This is my trimming tool made from a hub that sheared its studs. Not a lot of help as you need someone to do it for you. What it did show me was the tolerances between the shoes and the drum. Obviously the shoe has 2 pivot points that are fixed. The cam then pushes out the shoe to make contact with the drum.
Thats the problem when you fit new shoes. If you are lucky you can get the drum on with the cam at rest. Not always as easy as it seems. I had 2 or 3 sets that were all different. 2 sets were never going to fit and moving the window cut in the drum it was clear at the pivot point but way out at the cam end of the shoe. Even if I had got the drum on I would have lost most of the material at the cam end before I was making contact on more of the shoe.One side was worse than the other, I considered loosing some of the cam on one face as removing the arm and turning the cam round made little change.
In the end I removed the steel heel of the shoe that acts on the cam and trimmed a small amount of the shoe aluminum casting then refitted the heel. I did this twice till the drum would then fit on without losing friction material. The bottom shoe was a good fit but was rubbing the drum on the front edge not the back. all of this says to me that the pivot points are not always strait.. Shoe or my case?? Once I had trimmed as above I used the brake cam to push the shoes out and turned the hub shaving the friction material till It was making contact with the drum on a good 80% of the surface. In short a lot of FFaff for a simple job.
The blade above is just a bit of mild steel that I sharpened an edge on with my angle grinder. I fitted it parallel with the old shoes to it matched the working drum. Worth a go if you have a duff hub

[Dimitrios_231]

Clever engineering MK
I had done exactly the same,I didn't bother to weld.
I used 3 M5X0.8 threaded holes,I first tried some blades but they were very fragile,I ended up with a piece of sharpened mild steel.

[MK Monty]

No welding on mine drilled and tapped holes and as yours a mild steel blade. How did Lambretta trim the front ones?

[Dimitrios_231]

I have also thought about it many times,
assuming that the front hub must be perfectly round,like the rear hub,
a skimmed pair of rear brake shoes,should work fine on the front hub.
Just my thought.