Blue_Bulldog

This was spooky.

After doing some lubrication work on my moving parts, I'm pretty sure some got on my wheel rims and started sucking up road dust, because a day later, rear brakes started squeaking. Nasty, too. I knew dirty rims/pads are the first thing to check, so I tried cleaning stuff off with a couple of cleaners.... nothing. Checked alignment... everything was cool. But still squeaking. I really didn't want to swap pads out, since even though I have spares, I can't in good faith get rid of pads with plenty of rubber left on them. So last night I stayed over at a friend's place, and decided "forget it, when I get home, I'm swapping these suckers out." This morning, I got on my bike to ride home....

squeak was gone.

Literally just gone. Brakes were working like new. Like nothing had ever happened. I didn't do anything other than have it parked near a pine tree overnight in North Carolina fresh night air.

Am I the only person who this has happened to? Anyone ever had the squeak just up and disappear? And if I keep trying to figure the source out, am I looking a gift horse in the mouth? Should I just leave it alone, or is there actually something up?

FBinNY 

Yes, brake squeals can and go on their own seeming whims. The cause of squealing relates to the specific friction properties of brake shows and rims. Just like a violinist uses rosin on his bow to get the right friction, changes to the surface of the rims can cause squeal or make it go away.

My own commuter's brakes squeal when the humidity is just right, but not if it's sunny or raining. Or it may squeal for a day or two after some contamination gets on the rims, and stop when braking burnishes it off.

However, I have a question. What does red light, or a red light have to do with it?

Andrew R Stewart 

I've had more problems with super clean rims/pads or oil contaminated ones then with dry grime covered brakes. I have "cured" squeals with dirt from the roadside during rides and mulch chips. Andy.

Blue_Bulldog

If you sit at a red light long enough... it'll eventually turn green on its own.

HillRider

Not if the sensor isn't sensitive enough to "see" your bike.

zvez

So, newbie question. Is it advisable to clean off the thin layer of rubber that coats the braking surface of a wheel from use, or, as I believe, leaving this layer in place improves braking?

FBinNY 

Some do, some don't. I don't, and have enjoyed excellent brake performance (discounting some squeal now and then) and good brake track life on rims for 45+ years.

The only time I would clean a rim is if a stone got caught in the shoe and scrored the rim. Then I'd use steel wool or fine sandpaper (wet) to remove any loose flakes or shards of metal.

fietsbob

My sensor cannot see a darned thing ..

Chitown_Mike

Funny someone brought this up, mine started squeaking after I replaced cables and such the last week I have been fiddling with the bike. Unfortunately it is a bad squeak but it seems to come and go, because last night it wasn't there, but today it is bad.

jmpsmash

similar thing happened to me. lubing the RD pulley and a few drips went on the rim.

it didn't squeal until i started descending this hill but a few firm squeeze on the lever and a mile later the squeal was gone.

Delmarva

Squealing can come from a glaze (shiny stuff) that built up over time or from the lubricant. Very fine emery paper will take that glaze off rim and shoes. Wipe the surfaces clean with a dry cloth.