Sqealing brakes

[Big Sid]

On brake squeeling , might be loopy but I see it similar to a thin wine glass . Wet your finger and rub it around the rims edge and it will start ringing . I don't think it's the shoe vibrating but the cast iron drum . Only ever have seen one shoe shed its hook , this on many , many shoes . O rings in the grooves should damp out the effect . The spring around the drum lying in the fins seems a logical idea worth trying too . Sid .

 

[clevtrev]

On brake squeeling , might be loopy but I see it similar to a thin wine glass . Wet your finger and rub it around the rims edge and it will start ringing . I don't think it's the shoe vibrating but the cast iron drum . Only ever have seen one shoe shed its hook , this on many , many shoes . O rings in the grooves should damp out the effect . The spring around the drum lying in the fins seems a logical idea worth trying too . Sid .

Here`s where we improve Sids knowledge by at least 100%. In the picture you can see the offending ( or rather can`t see) ear, and its roadside replacement, this was somewhere in France, it took about twenty minutes to get the brake plate off ! such was it jammed.
Interestingly Sids comparison with a wine glass gives a clue here as well. If you understand how wine glass resonance occurs, you will know that if the resonance is increased greatly, the glass will shatter. Consider that happening to the ear on the shoe.
I`ve had 3 ears break, all using AM4 linings, at the time I was experimenting with various styles of brake plate. AM4 I would consider to be a (now) thinking similar to the glass resonance, this caused by the slip/grip movement of the finger on the glass, press a little harder and you will not get any resonance, owing to the fact that you have compressed your fingerprints, and there`s nothing to give any slip/grip. AM4 with its impregnated material, I think, gives the same effect. So under heavy pressure the noise will disappear, which is probably why it was developed for racing, that being the major requirement, not for gentle braking, seen with road bikes.
Conclusions, I went off AM4 and had no more squeal.
Anyone know what the red braking material was, from way back ?

 

[ossie]

as well as riviting the linings on i do fix them to the shoes with araldite which eliminated most of the squealing.
as well as all the recomended champhers.
the elastic band bit was just a comparison to show how they stopped the vibrating or ringing.
and i dont use this on my drums [shadow front and rear]
it was always the fronts that squealed.
OSSIE.
new type linings i belive do not take to riviting and are bonded on so maybe dont squeal.???

 

[TouringGodet]

Brilliant idea to use a master link.

I agree about the non-resonance of the brake drum. Especially with two separate brake shoes both pressing against the drum, I don't see how the drum would be able to resonate. If you touch the wine glass somewhere else besides the rim, or press too hard with your finger on the rim, it will not resonate.

 

[ossie]

so your fingers are doing what the elastic band will do????

 

[bmetcalf]

Now you're making me paranoid about my AM4 linings!

 

[stumpy lord]

I allso have had three broken ears off brake shoes when using am4 linings. as for squealing clutch drums, the only time it has happend to me , is when the clutch was full of oil, when the linings where de oiled (heat applied to the shoes to burn of the oil) the clutch no longer slipped and the squealing had vanished.

stumpy lord

 

[Big Sid]

Might have something there . There is a thin pad placed under some brake disc segments on cars that eliminates the noise . This suggests that bonding has that effect as suggested . We have been using on our own bikes shoes with those bonded on truck linings earlier mentioned and they don't make the noise . Sid .

 

[Howard]

OSSIE.
new type linings i belive do not take to riviting and are bonded on so maybe dont squeal.???[/QUOTE]

I've just had mine relined by Classic Brake Services, lovely job, no squeal, bonded and riveted with modern lining material.

H

ps

Mac, you might want to check the drums. If they're not round, they can cause squealing - similar reason to Trev's above, on light braking the shoes touch then miss then touch, and can start a vibration - when you brake hard there's more even contact.

H

 

[Viny4]

I have 4 Vincents with Alloy Backing Plates and they all squeal. I had never had a squealing problem till Mardy Dickerson mentioned that it was common with Alloy B/P. After that! Smith.