Deafening brake squeal

[Chuffy]

Evening all.
I have a 1974 Carlton equipped with Wienmann centre pull brakes like these.

The brake pads are modern Kool Stops

Rims are aluminium.

The brakes squeal like a pig with it's balls in a mincer. They're so loud that I'm seriously considering just riding into walls, parked cars and old ladies in order to stop. Anything rather than pull the brakes on.

I don't think you can toe these in as they don't sit on a stack of adjustable washer like modern brakes do.

Any ideas/tips/advice?

Cheers,
Chuffy

 

[HLaB]

I would guess they are not hitting the rim square; the way I've squared brakes is to loosen them pull their lever tight and tighten (I don't know if it'll work for those brakes though). Another possibility is the rim is out of true (same out come) or the rims are contaminated, clean with a clean cloth if that the case.

 

[Fab Foodie]

Nice to see you Chuffy!
They squeal, that's what they do, they always did IIRC, probably because they're not the most rigid of brake designs. Not much help I know!

 

[Crackle]

I had them. What's these adjustable washers you talk of. Brake pad out, wheel out, screwdriver in and twist to toe but yeah, they squeal, though not as much.

 

[Chuffy]

I would guess they are not hitting the rim square; the way I've squared brakes is to loosen them pull their lever tight and tighten (I don't know if it'll work for those brakes though). Another possibility is the rim is out of true (same out come) or the rims are contaminated, clean with a clean cloth if that the case.

They're square alright (that's how I fit my brakes too) and the rims are brand new. They squeal on both front and back brakes, although with slightly different pitches, so on a long descent I can play simple tunes.

@Crackers and FF -

The brakes actually work pretty well, so they must be fairly stiff. There is *no way* that they should sound like this, it's deafening. Might try poking a screwdriver through and toeing them in Russian style....

 

[tyred]

Take the caliper arms off and grease the pivot points and re-assemble. Doing so silenced the Mafacs Racers on my Pug which are a similar design. Also ensure the arms as tight as you can get them without actually sticking on. Make some shims to take up wear if necessary. The squeal is caused by the vibration of the arms (IMO) and anything you can do to minimise this is good. Adjusted properly, these are fine brake.

 

[Chuffy]

Take the caliper arms off and grease the pivot points and re-assemble. Doing so silenced the Mafacs Racers on my Pug which are a similar design. Also ensure the arms as tight as you can get them without actually sticking on. Make some shims to take up wear if necessary. The squeal is caused by the vibration of the arms (IMO) and anything you can do to minimise this is good. Adjusted properly, these are fine brake.

Will give that a go, cheers.

 

[al-fresco]

I used to have those brakes! (Can't remember them squealing though.) I quite like my brakes to make a bit of noise - handy for clearing kids out of the street and letting my mates know that I've finally caught back up.

 

[Banjo]

Have you tried scrubbing the rims clean ? I put a drop of wd40 on each spoke nipple on my alloy wheels. A tiny bit must have got on the rims.Result was an incredible screach.

I looked over my shoulder at first thinking my bike couldnt have made that much noise.

A scrub with a nail brush and soapy water sorted it out.

 

[Angelfishsolo]

Have you tried scrubbing the rims clean ? I put a drop of wd40 on each spoke nipple on my alloy wheels. A tiny bit must have got on the rims.Result was an incredible screach.

I looked over my shoulder at first thinking my bike couldnt have made that much noise.

A scrub with a nail brush and soapy water sorted it out.

May be worth sandpapering the pads as well just in case they have picked up some crud.