unusual drum brake

Looks like an 8 leading shoe drum brake to me. Read about them somewhere, presumably offer more braking power than 4LS, but are more complex and difficult to adjust correctly.

If they offered any overwhelming advantages we'd see more of them. Why are disc brakes so common?

bazzee
 
C.M.A. I think - I saw my first one in the metal a few weeks back at the Burt Munro. Fitted to a 750 Domiracer.

That one has had a fair amount of time spent drilling extra holes too.

As I recall they appeared only a year or so before the first good discs - unfortunate timing.
 
Work of art reckon it would have worked OK to if set up properly... drums stop better than disc's for the first or second but then are prone to fade a lot e than disc's hence the popularity of disc's.
 
is it a Cerhan Mckay?
I can tell you how to deal with it, sell it for about 1000 GBP and get some discs
CLEM
 
Quite a work of art, but can you imagine how much force you'd have to apply just to overcome the 8 return springs, before you even started forcing the shoes against the drum? And those outer cables look pretty thin to me, I'd be prepared to bet there's quite a bit of compression there too.
But one of those would be nice on a 180. You'd even end up with symmetrical (hypertrophied) forearms after a while, excessive force needed for clutch AND brake.

Ken
 
There was a company in the UK making them in the 60s/70s, can't remember the name of 'em though. A bloke I know in Kidderminster bought a Gold Star a couple of years ago in s**t order for relative peanuts fitted with one, Gawd knows why the damn' thing probably managed about 30bhp at most. After he rebuilt the bike into a thing of beauty he flogged the 8LS brake/wheel for ?1000. Why do these things always happen to other people ?.  :(
 
GregT said:
C.M.A. I think - I saw my first one in the metal a few weeks back at the Burt Munro. Fitted to a 750 Domiracer.

That one has had a fair amount of time spent drilling extra holes too.

As I recall they appeared only a year or so before the first good discs - unfortunate timing.
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that's it greg.. guess it was called a Dresda from CMA.
 

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I had a yarn to the guy i saw using one at the Burt Munro - asked about setting up etc...
Both him and I set up multiple leading shoes from scratch by setting the linkage to a neutral position and machining the shoes on the backplate. Never touch the linkages again.

He was using it in a race class which only allows drum brakes. He was outbraking a very well ridden Manx which had the late 4 shoe double sided Norton brake - so I guess it was worth it.
 
From my own limited experience with an 8LS front brake (a Robinson fitted to my brother's Kawasaki Mk III) they work well at highway or race track speed but deadly when pootling through city traffic. At low speed the servo-effect of the 8 shoes is such that it'll lock up as soon as the shoes touch the drum. I found the only way to ride it in stop-start traffic was to leave the front brake alone and use only the rear brake for stopping at traffic lights. Once stopped, it was OK to use the front brake to hold it on a hill if you needed tom take your foot off the peg.

They do look the business though  :P

Cheers,
Cam
 
Dellortoman said:
deadly when pootling through city traffic. At low speed the servo-effect of the 8 shoes is such that it'll lock up as soon as the shoes touch the drum
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Early Japanese "scramblers" that were just road bikes with high handlebars and exhausts systems, like 450 and 350 Hondas, still usually had the road DLS front brakes. Totally useless off road, would spit you off in an instant; same brake was also pretty useless on the road too, especially after a couple of hard stops, they'd fade to nothing. Holes and scoops helped when they were set up for the track, but even the earliest production discs were better.

Ken
 
i must confess i never knew that there was anything beyond a 4LS until this week. Probably a good thing as I've already built my wheel with the Grimeca 4LS..
 

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The top box on the back of that bicycle looks handy. Although the handling might be a bit iffy with it full of beer.  :D

bazzee

Oh - is the front brake on that Triton a Grimeca? I didn't know that they made 8LS drums, thought that was the realm of small niche manufacturers.
 
No 8LS from Grimeca to my knowledge, they stopped at 4LS.

Got a nice 260mm Yamaha 4LS lying around in the workshop, will fit it to a Laverda some day.  Pity it has a 15mm axle though, won't be a heavyweight then... :-\

piet
 
I go along with Dellortoman. I had an 8LS brake on a Peckett & McNab Triumph I used to race back in the seventies. terrible fade but ok on the track. Absolutely deadly paddling around the paddock. Bump starting it in the paddock was a bloody nightmare. You'd jump on sidesaddle and get the motor spinning .... just look at the brake lever and it would would stop dead, like you'd hit a brick wall and chuck you over the other side of bike head first.... all at about 3mph. All very embarrassing. Did look the biz though.
 
troutbishop said:
A friend of mine sold one about a year ago I offered him ?1k for it but someone offered him more I realy wanted it for my Rickman .
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If that fella was Geoff W. in Kiddie Kev, that was the brake that I posted about. The Goldie belonged to a chap with about a couple of teeth left in his head (must have lived on nuthin' but puddings !) who spent many hours loitering at Alec's shop in Stourport, booring the backsides of both him and Ben.
                                                            Dave.
 
I think it's a brake Campagnolo (1975) had inspired the work of the Italian engineer OG GONZAGA in 1960, and the brake of my childhood friends, brothers LUCHIER, who filed the patent in 1973 and developed this principle in the race (Bol d'Or and 24 H Le Mans 1980) with drivers and Roger Ruiz and Darryl Pendleberry.
 
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