Front brake assembly

Information relating to the Matchless G12 or AJS Model 31 650cc twin
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ajscomboman
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Re: Front brake assembly

Post by ajscomboman »

I can't make 40 yrs but have got to 37yrs of AMC and I'm only 54!!! Is that just sad or what? Started down this route at the age of 17, old before my time. :(
Mick D
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Re: Front brake assembly

Post by Mick D »

raffles wrote:What MUST be done____ set it up in a vice spin the wheel and with a ring spanner on the brake arm nutlock the brake on tighten the outside nut fully before you release the brake this centralises the brake
Hi

I find it easier to set the inner nut on the bench then fit the wheel, centralising the brake and torqueing the nut as part of the process - let the forks hold the spindle it's what they're designed for - unlike a vice ;)

Regards Mick
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ajscomboman
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Re: Front brake assembly

Post by ajscomboman »

Gotta go with raffles on this one, do the very same thing as him and never had a back plate come loose, ever!
56G80S
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Re: Front brake assembly

Post by 56G80S »

I think that either way works but the important thing is to do it. Personally I seem to remember that I do this on the Matchless but with the assembly fited the "wrong way", outside the forks and the bottom clamp does the job fine.

Let's see 1973 to date, all that riding up and down to London for the first 3 years. About 45 years? And still know nowt.

Johnny B
Ajaydave
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Re: Front brake assembly

Post by Ajaydave »

Which is the leading shoe, should the trailing shoe be trimmed, ??
SPRIDDLER
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Re: Front brake assembly

Post by SPRIDDLER »

Have a look at my post from 2013 which I reposted on Friday which also shows how to identify the leading shoe.

viewtopic.php?f=17&t=12693&p=115566#p115566
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Which taken at the flood............'
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clive
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Re: Front brake assembly

Post by clive »

Spriddler there is another method to achieve improved braking, allow the brake operating parts to wear out the bush through which they operate and the shoes will tend to centralise themselves to equal out the pressure between leading and trailing shoes. I keep thinking I should do something about it but so long as the brakes are good......
clive
if it ain't broke don't fix
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Joker_Bones
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Re: Front brake assembly

Post by Joker_Bones »

After assembly, and with new linings, my front brake was horrible.
Ineffective until you applied lots of pressure then, screeched and grabbed.
I did this...

120 grit paper, double sided tape, to linings. Then.


7.jpg
Permanent marker to drum.


8.jpg
Assembled with shoes centred, tension to brake arm, span wheel to see what was happening.


9.jpg
Rubbing on trailing ends of linings only.


10.jpg
Drum slightly out of round, kept spinning the wheel till lines cleaned off, adjusting the position of the shoes up and down to get the full width of the drum.


11.jpg
Reversed the process, paper to the inside of the drum. Abraded the linings to remove the high trailing ends.
I guess if you went too far abrading the linings you would cut them too small by the thickness of the paper, so I only abraded them to get rid of the high trailing ends.
Brake no longer screeches or grabs, is smooth and reasonably effective.
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CAB
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Re: Front brake assembly

Post by CAB »

Hello
Great minds think alike even down to the bungee cord on the bench.... I did this several years ago but I still have no confidence in the brakes compared to my 1969 (sorry to say here) Triumph with its 8" TLS brake. I've done all the brakes mods (shortened the material on the trailing shoe) and centralised it but I can't say that there is any real improvement. There is no grabbing, vibration or noise but not a lot of stopping either. I've just removed the wheel, I'm going to strip it, get the original rim re-chromed then rebuild it and get the drum trued and get oversized linings turned down to size. I noticed that the linings in your wheel are woven. Did you get these from Saftek? Is it the lining they call "green-gripper"?
I have a horrible feeling that all this isn't going to make much of an improvement.... My uncle has ridden my bike and he thinks the brakes are great compared to his Enfield with its double sided SLS drums and even his Nortons with 8" front (SLS) drums.
CAB
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Joker_Bones
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Re: Front brake assembly

Post by Joker_Bones »

IMG_20220829_101852.jpg
I only have anecdotal evidence as to what they are...
I bought this hub complete with brake at a local jumble. The fella I got it from was keen to tell me the new linings were by Villiers Services and in his words "the only ones worth having".
When I abraded them I noticed the material contained shiny particles, which under magnification looked like tiny lengths of fine brass wire?
At the moment they are similar in effectiveness to my other 350 and G12, which do not have this type of lining, but I have done liitle miles with them, they may bed in further.
I did notice they are more audible than my other bikes, if you apply the brake lightly and push the bike along their rubbing is much more noticeable, perhaps just because they freshly abraded.
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