I've recently acquired a very late model 199b. Likely one of the last dozen built. In any case like most of these bikes the chrome lining has peeled off both brake drums. Over the years on this forum and elsewhere I've read how good the puma or Vazquez brakes are. My question is this. Where is the cast iron sourced from? What size can you get it in. I have a machinist that can install it but we are having issues on where to buy the material. Any thoughts ?

Steve

Why not just use Bultaco UK ?

I can as a last resort but I live in western canada. The exchange between canadian dollars and the the british pound is about one and a half times. Add to that the shipping and it will be quite expensive.

...and there is a perfect example of why filling in your profile helps with answers.

 

Very late bike? Does it have the alloy head steady? Forks with pinch bolts in only one side and a frame number close to 5000?

Yes. Alloy head stay. Forks only drilled on one side. 14644 is serial number. Impossible to know for sure but I think the last number built is approximately 14653.

Steve

Edited September 30, 201510 yr by stevem75

try the inner part of a car brake disc if you can find one near the size then machine 

As per last post, that seems to be the best source of supply if you can find them. Can't verify about the Puma / Vazquez bikes but I don't think any of the liners fitted here use cast iron as no-one seems able to get it. Several of mine have been done with 'ordinary' steel (don't ask what grade etc. I've no idea and know nothing about metal grades) rather than cast and with modern brake shoe linings are perfectly acceptable in terms of efficiency most of the time - no drum will every be 100% consistent when full of muddy water and sludge (typical UK conditions)

Yes. Alloy head stay. Forks only drilled on one side. 14644 is serial number. Impossible to know for sure but I think the last number built is approximately 14653.

Steve

Yes its late, ive got 4619 as my latest, last is 4663 if the sherpa book is right.

 Interesting that the puma bikes dont use the cast iron liner.  I found someone in wisconsin who can do a steel liner and has had great success with it.  I'll likely try him and see how it goes

 

steve

TBH a steel liner will work well enough. If you look at the chrome finish then a steel must offer significantly more friction?

Cast would be better till wet as woody says.

I have used steel on all of mine as opposed to cast iron, the reason being is that cast iron has basically graphite in the microstructure which makes the surface greasy to touch and aids in lubrication ie liners and piston rings, not really what you want for a brake surface.

I have used both cast iron and steel. No sure what grade of steel I have used but it was a disaster and I would never waste my time again with steel. Despite trying different grades of brake liner material I just could not make it work, On the other hand my experience with cast iron has resulted in brilliant brakes. The front brake on my 199 easily works with just one finger. Newfren liners do not work well with cast iron to be honest in my opinion they seem not to work well with any material!. I use fork lift truck lining material bonded onto original shoes by a company in Yorkshire.(saftek)

 

Cast iron is difficult to obtain in tube form. I buy a slice from a solid bar usually from College Engineering Supplies in Birmingham (UK) who will cut a blank to my exact width. Expensive but it least you can get it. I then drill a series of holes and cut or knock out the middle which goes in the scrap box for possible other jobs. Then onto the lathe. The first cuts are interesting as the jagged surface from the holes gives the tool and lathe a very hard time. It takes me a couple of hours to produce a blank for final machining but my time in the workshop in the evenings is cheep. Domestic oven in the kitchen to heat the hub prior to final assembly. After 30 years of marriage my wife is used to this and also finding cast iron rings in the freezer.

 

Stuart

Why not just use Bultaco UK ?

 

I contacted them (InMotion) in the beginning of 2014 and they told me they don't do the re-lining anymore because of risen expense.

They did offer me to give me the contact details of the work place were they had them done, but I eventually found someone in France.

 

I'm pretty sure mine's also done with steel liners, and it's a very noticeable improvement over the chrome liner.

I do have the intention though, to use EBC or fork lift brake shoe material instead of the Newfren next time, to see if it's an additional improvement.

Edited October 1, 201510 yr by guys

I have used steel on all of mine as opposed to cast iron, the reason being is that cast iron has basically graphite in the microstructure which makes the surface greasy to touch and aids in lubrication ie liners and piston rings, not really what you want for a brake surface.

All proper racing brakes, eg. Fontana, Oldani, grimeca etc had cast iron liners.

My worry with cast iron would be that it rusts very quickly, would definitely need wheel removed after every wet trial.

There are lots of different types of cast iron, not to mention cast steel, all with their specific properties. So comparing cylinder linings with brake material is not a good idea.