Squealing brakes

hostman

Hi,

I have squealing brakes, front and rear, even at low speed, it's horrendous. Shimano 105 5800 dual pivot. I replaced the pads yesterday and gave the wheel rims a good clean along the brake area, rode today and it is better but still squeals under higher load, i.e. braking down a descent.

I can see thin black lines embedded along the rim, oil / dirt presumably. Can I use something stronger on the rim to remove more of this stuff, a degreaser on a cloth for example? Or is this going to make it worst?

lemonenema

if you want to clean the rims thoroughly clean with soap + water or all purpose bike cleaner like fenwicks, and wipe over with surgical spirit / alcohol / methylated spirit. Take care not to get alcohol on the tyre, take it off if youre a bit heavy handed. I would only use soap/bike cleaner on the brake pads too as alcohol can damage rubber.
Seems strange though Ive never had rim brakes squeal since the days of old cantilever brakes.
Check online about setting up brake pads - slight toe in and simultaneous contact both sides.

photonic69

Usually contamination causes this.

I've used metal rubbing blocks as per this link in the braking tracks:

Garryson Garryflex Abrasive Block - Fine 240grit

https://www.amazon.co.uk/dp/B0001P08UG/ ... CCbY88A03H

Use with plain water. Rinse clean. I sometimes put a bit of white spirit on a cloth and wipe it over the brake track. This will remove all contaminants from the wheel. Remove brake blocks and rub the faces on a bit of 120 Wet and Dry (used dry) to remove any glazing from the pads.

Set toe in using a thin card at the rear of the pad. DHB labels are just about the perfect thickness to set toe in.

lemonenema

white spirit?! this leaves an oily film, so yea would stop the squealing and make you go..faster.... I doubt anyone else would advise using white spirit

photonic69

lemonenema wrote:

white spirit?! this leaves an oily film, so yea would stop the squealing and make you go..faster.... I doubt anyone else would advise using white spirit

White spirit is a degreaser. I've used it countless times after lubing a chain and getting droplets of lube on the rims. My brakes work very well.

imposter2.0

PhotoNic69 wrote:

lemonenema wrote:

white spirit?! this leaves an oily film, so yea would stop the squealing and make you go..faster.... I doubt anyone else would advise using white spirit

White spirit is a degreaser. I've used it countless times after lubing a chain and getting droplets of lube on the rims. My brakes work very well.

That's because it's a solvent - but it's an oil-based solvent, so I wouldn't be using it on my rims, tbh. There are lots of products that will clean rims that aren't oil-derived.

hostman

Issue fixed, spent some time cleaning the rims thoroughly with some degreaser and a brillo pad to remove more embedded residue, also toed in the brakes.