FT: Frame (Twin) New 7" Brake Shoes

[davidd]

Vincent,

I could only understand a very small portion of what was in the book. I think I have conveyed it correctly, but it would be nice if someone else understood the subject. It does contain much that is understandable.

The drum brakes analysis starts with what they call the "basic circle", which is used as a standard to do the more specific geometry for shoe factors and lining pressures. The pressure calculations are here and I stop before the next section, which is the shoe factor calculations:

Even without a full understanding of the material, it becomes apparent that the geometry of a brake is not to be taken lightly!

David

 

[Vincent Brake]

i print and read tonight over a glass of wine!
thnx David, nice book!

 

[Martyn Goodwin]

Vincent,

I could only understand a very small portion of what was in the book. I think I have conveyed it correctly, but it would be nice if someone else understood the subject. It does contain much that is understandable.

The drum brakes analysis starts with what they call the "basic circle", which is used as a standard to do the more specific geometry for shoe factors and lining pressures. The pressure calculations are here and I stop before the next section, which is the shoe factor calculations:

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Even without a full understanding of the material, it becomes apparent that the geometry of a brake is not to be taken lightly!

David

Cripes - my head is in a tailspin!

 

[powella]

Road side repair - some time ago now !! Look familiar ?

 

[vibrac]

Well there is a lot of math there but not a lot of conclusions one thing I can agree with is if you extend the linings over the 'valley' on a Vincent shoe then the center of the lining wears appreciably more than the ends
One thing I will try is a softer lining on the trailing shoe that 'good brake feeling' time after new linings that soon goes away needs extending

 

[Matty]

There was a time when replacement brake shoes for the post war bikes were difficult to source. I have been involved with the development of replacement shoes and a photograph is shown of the items. They are made of LM25 heat treated and several changes (hopefully improvements) have been made to the originals. They are stiffer than the originals by incorporating stiffening webs. They do not have the small tongues sticking out to take the springs. Instead they have robust through holes. In addition they do not have the dips at the end of the brake linings which allows a longer lining to be use if wished. They will be supplied in pairs only, complete with the spring and metal end plates (H48) fitted. The price, per pair is £80 and you can organise the fitting of your preferred linings if you wish. Alternatively, they can be supplied with linings suitable for touring use or alternatively for racing use if you wish. The price for touring linings fitted is about £12 per shoe.
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[Matty]

Hi Timetraveller
The brake shoes could well be of interest to me, but where can I buy them please - presumably on line.
Matty

 

[timetraveller]

Not on line. You have to buy them through me but at the moment I am still waiting for the lined shoes to be returned. Some thing are going very slowly at the moment and I don't know where the hold up is.

 

[Matty]

I sent my old brake shoes to Saftec on Friday and they said when I rang them, that they arrived Monday 4 May and will be shipped this week with Green woven linings which I hope to try for grip when I have fitted them.
Will have to sneak out to get some medication and milk at a service station 2 miles away - but this will hardly be far enough for them to bed in and for me to make a proper assessment.,

 

[vibrac]

You have a job to beat Saftec turn around knowledge and expertise they can certainly turn a clutch plate covered in holes for cork insertions into a full face dual sided non slip item in 3 days door to door