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+--- Thread: Lined Brake Drum? (/showthread.php?tid=4205)
Lined Brake Drum? - Colin Morgan - 16-04-2020
Looking at one of the old late-chassis Girling cast brake drums I have here, it seems to have been lined at some time using a steel ring about 1mm thick.
Is this something that was done at one time, please? There is some corrosion so the the drum and ring are starting to part company. I am not planning on using it.
Colin
RE: Lined Brake Drum? - Tony Betts - 16-04-2020
Hi colin,
I've had a few of these in over the years, so it was definitely a common practise.
I recall they were held in with little rivets, so there is a small dimple on the outside of the drum.
This stopped the liner turning in the drum.
Tony.
RE: Lined Brake Drum? - Colin Morgan - 16-04-2020
Thanks, Tony - yes, I can see the rivets when I look closely. If it hadn't been corroded, I wouldn't have noticed. New to me - not up with all the ways of the past.
Colin
RE: Lined Brake Drum? - Bob Culver - 16-04-2020
This would seem a diabolical idea. If the contact was not perfect and the liner ever got really hot as in a long descent it woud take a set and become loose. Maybe the pressure from the shoe always ensured sufficent conduction. Presumably the speciallty of some one firm as too laborious for a one off. Oversize or packed linings far more simple.
RE: Lined Brake Drum? - Stuart Giles - 17-04-2020
When I was a proper newby I owned a car with a massive brake pull. I spent quite a lot of time on brake adjustment, chalking the linings to check consistent contact area etc. When I finally swapped the brake drums side to side and immediately swapped the massive brake pull from one side to the other, close inspection of the drums revealed the two different friction surfaces, where only one drum had a steel liner. Apart from the fact that the steel liner has poor braking friction by comparison with cast Iron, there isn't a great deal of original brake drum metal material left around the shrunk in steel liner. A brake drum failure at any speed could spoil your whole day; so any of these I come across (either I'm unlucky or they do seem quite common) go straight to the scrap bin.
RE: Lined Brake Drum? - spannerman - 17-04-2020
Fitting a liner in classic competition motorcycles is common practice , but they do use a cast steel liner , I've not known of a problem with professional done ones and the drums do get very hot when racing? Have been involved with bike racing for 30 plus years and not seen one fail yet!
RE: Lined Brake Drum? - Bob Culver - 18-04-2020
It always intrigues me that, apart from considerations of spring, it is adamantly claimed that ci has higher friction.This despite it being less in most applications. So many have been soaked in oil would not expect to be as effective as seem to be.
A 1mm steel lining does seem amazingly thin, .
RE: Lined Brake Drum? - Colin Morgan - 18-04-2020
Here's a picture of the offending item. It has obviously done many years service.