This will happened if you fail to do your braking UPRIGHT -which is the correct method to chose- the lock ups you had on drum brakes where not on Norton brakes?
Came across a fatal bike crash yesterday
- Thread starter ashman
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I mainly use two types of drum brake. One was made in Australia and I was an idiot for trying to use it. It had huge springs on the brake shoes which should have told me to stay away from it. I think the reason it had too much self-servo was because the cams were at the wrong centres. The other brake was 7R AJS. It was a treacherous bastard. To get it acting quick enough, I extended the lever to make it one-finger operation. When I crashed the bike and damaged myself, it was mainly because I was slightly out of practice and grabbed it that bit too hard. But with disc brakes, you can actually grab a handful and they will stop the bike without locking. And when you let go, they come off - they don't stay on and cause the bike to steer off into the boonies. The problem with this stuff, is that if some kid gets caught by a locking brake, they can crash and get killed and the cause of the crash might never be diagnosed. In Australia, there is one historic race class in which every bike has a drum brake. It is the reason that Seeley G50s never race against Manx Nortons in Australia - So what have we lost ?
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Bernhard, why are you guys so fussed about braking UPRIGHT ? In racing, you usually brake right up late into the corner, so the bike is always cranked over while you are doing it. With a disc brake, there is no problem in doing that. Not so with a drum brake - most of them are unsafe.
Craig
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not just kids making mistakes .... M. Marquez maybe best rider in the world today and he is just a kid .... a week ago here a 60 yr old going to work on his bike got clipped by a deer , in daylight , very rare .... no mistakes were made ,sadly the rider died because the deer decided to bolt at the wrong time .... a fellow gave me a pin couple years ago after I had dropped the Ducati ... pin say " shit happens " ..... just sayin'
Craig
Craig
ashman
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My rear drum works great on my hot rod 850 Featherbed but I also have a full Grimca front disc brake set up on the front the rear drum works so well together with my brake set up, but I hardly use my brakes when out riding I slow down before the tight twisties without using my brakes and power on when into the corners, but its great knowing I have a good brake set up when needed, having the right MC, braided line and 12" floating disc with matching racing calaper all plays a big part, its one of the best improvements I have done to my Norton, the orginal Commando disc was just never up to it, it let me down in a big way twice before I went the Grimca way.
Ashley
Ashley
Re; "Not so with a drum brake - most of them are unsafe"
I take exception to this comment; you openly admit that the drum brakes you fitted were faulty in some way. My 750 was fitted with alloy rims, then the drums skimmed true and then the brake plates sent to a professional brake shoe service, that openly advertised in the motorcycle press, and fitted with green shoes on the front and brown on the rear and skimmed in a lathe to the EXACT size of the brake drum diameter when .020 thou shims were fitted under the shoes/cam pin for this operation. They were as good as you could get. And yes, I have braked hard into a corner, more so with a disc when I have overshot the apex, or my braking point; but with a drum brake there was so much brake lining in contact with the brake drum that it would be the point of foolhardy to have anything but light finger pressure on the front lever whilst banked over-you learn as I did to do all your main braking upright on drum stoppers. I over took so many disc braked guys into a hairpin it looked as if they were sandbagging!
I take exception to this comment; you openly admit that the drum brakes you fitted were faulty in some way. My 750 was fitted with alloy rims, then the drums skimmed true and then the brake plates sent to a professional brake shoe service, that openly advertised in the motorcycle press, and fitted with green shoes on the front and brown on the rear and skimmed in a lathe to the EXACT size of the brake drum diameter when .020 thou shims were fitted under the shoes/cam pin for this operation. They were as good as you could get. And yes, I have braked hard into a corner, more so with a disc when I have overshot the apex, or my braking point; but with a drum brake there was so much brake lining in contact with the brake drum that it would be the point of foolhardy to have anything but light finger pressure on the front lever whilst banked over-you learn as I did to do all your main braking upright on drum stoppers. I over took so many disc braked guys into a hairpin it looked as if they were sandbagging!
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Re; "Not so with a drum brake - most of them are unsafe"
I take exception to this comment; you openly admit that the drum brakes you fitted were faulty in some way. My 750 was fitted with alloy rims, then the drums skimmed true and then the brake plates sent to a professional brake shoe service, that openly advertised in the motorcycle press, and fitted with green shoes on the front and brown on the rear and skimmed in a lathe to the EXACT size of the brake drum diameter when .020 thou shims were fitted under the shoes/cam pin for this operation. They were as good as you could get. And yes, I have braked hard into a corner, more so with a disc when I have overshot the apex, or my braking point; but with a drum brake there was so much brake lining in contact with the brake drum that it would be the point of foolhardy to have anything but light finger pressure on the front lever whilst banked over-you learn as I did to do all your main braking upright on drum stoppers. I over took so many disc braked guys into a hairpin it looked as if they were sandbagging!
Was this Joe Dumphy ? sadly now gone .. wonder who does similar service in UK these days?
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Villers and Saftek in the UK will fit new linings to old shoes and the lining thickness they fit will be calculated from the sizes you supply for the drum ID and the OD of the shoe casting on the brakeplate. As I have a gap bed lathe I can turn them on the brakeplate so can play with the figures I give them so the lining is slightly oversized. The last one I turned had nearly all the excess was taken off one shoe due to the brakeplate not having the shoes centralised by about 10 thou.
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The theory is great. But what happens when you are running out of road with the brake hard on and the leading edges of the brake shoes become sticky, grab and launch you ? You can taper the leading edge of the linings right back, but there are no guarantees. You find out when you land that the theory did not work.
ashman
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Well talking about brakes and how to use them doesn't bring this poor bugger back, what ever happen he made a big mistake that cost him his life the only sign of heavy braking was on the edge of the road on the dirt no skid marks on the bitumen, he just missed the corner but shorely he seen the tree line off the road, this corner comes up quick but is easy to get around it even at speed, we all make mistakes but where it happened something has gone really bad was it speed or just a major mistake on his part we will never know.
Ashley
Ashley
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A few years ago the guys were building chopper with extended front ends. My mate watched a dead guy being carried out of a stand of trees after a chopper took him off the road. To me it is a real tragedy when something so simple does an enthusiast in. Some people don't have such lovely interests in their lives. And most bystanders don't appreciate what the attraction is.
The small 30degree taper filed onto the leading edge of the brake shoes is vital to prevent the wheel locking up. Even a puny 4 inch diameter will lock up without this taper.
Don’t understand your comment unless you were using too soft a compound break shoes for racing.
As for the brake from a 7R AJS, you must have done something wrong somewhere, you are the only person who has complained about these racing bikes brakes – I cannot remember anyone else ever complaining about these –ever. Cannot comment about your other unknown brake since it seems a one off experiment!
As for the one finger braking on drums- really? –yes really?
You would need to set the drum brake arm larger than the recommended 90degrees when fully on- a sure fire way to get a lock up on a drum break front or rear you must have either been ignorant or nuts to do that-or both
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Yes it was, if you were around at the time you might have seen my bike outside his shop in Sydenham at least 3 times with the bike balanced perilously on its centre stand without wheels!
There is this company, but I think they take 6 months to do it!
http://classicbrakeservices.vpweb.co.uk/
There was a place in the classic bike press in Leicestershire somewhere. . . .
https://www.bing.com/search?q=brake...-43&sk=&cvid=3FBC99E3357C406A8D8BE737D29A84F3
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Yes it was, if you were around at the time you might have seen my bike outside his shop in Sydenham at least 3 times with the bike balanced perilously on its centre stand without wheels!
There is this company, but I think they take 6 months to do it!
http://classicbrakeservices.vpweb.co.uk/
There was a place in the classic bike press in Leicestershire somewhere. . . .
https://www.bing.com/search?q=brake...-43&sk=&cvid=3FBC99E3357C406A8D8BE737D29A84F3
Just checked Supreme motorcycles now taken over by Dragonfly ... good article but no mention of service. Ferodo used to do this up at Chapel en le Frith but again no more.. Classic Brake services look promising and they there near comparatively near by.
I Don’t think you have thought this through-Mr ‘ealth and safely would have a field day if they came round-ever wondered why it is so there are none of the old boys are around anymore and it’s difficult to get this service now?
The old brake shoes were asbestos, although, you can get non asbestos shoes now.
I would need a powerful vacuum cleaner lined up to catch the dust, throwaway over suit and dust mask before I would use a lathe for this operation!
You would also need a supplier to provide oversize brake shoes-not sure Ferodo will do that anymore.
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Yes they were asbestos true enough and I wonder if the current linings are really any safer... and yes you would need pretty serious extraction but that is surely not impossible to arrange... and a dust mask... but so too with many industrial operations . Doubtless health and safety would pay a visit -they never get too exercised about the big players and have to justify their existence . Would have thought though that getting hold of the linings would not be an issue.. just order from reputable Brit supplier and they are already well oversize...
I suppose the old boys are underground and to the next generationn there was a perception there would be no money in it which is the real reason its gone
I suppose the old boys are underground and to the next generationn there was a perception there would be no money in it which is the real reason its gone
