bici_mania

When I ride I will randomly hear a high pitched squeal/squeak. It is either coming from my bottom bracket or rear wheel though I am fairly sure it is the rear wheel.

I am unable to reproduce the sound with the bike in the stand. I am also unable to predict/reproduce the sound at will when riding. Usually, not always, usually I am standing and/or going up hill. It will be one or two random squeals and then it goes away again. Roughly, it occurs once or twice every 10 miles or so.

I wipe my bike and chain down before and after every ride. I lube then wipe the chain after two or three rides, roughly once every 100 - 150 miles or so.

I typically drip a few drops of lube on the pulleys, hinges and spring on the derailleurs every other chain lube or so.

Yesterday I disassembled my rear hub, cleaned and re-greased everything. On this morning's ride I got about five miles down the road and there was another dang squeal.

Any thoughts?

pursuance

My beater has old SPD MTB pedals and the left one started to squeak.
I could silence it by kind of side loading my foot.
These are non-rebuildable, so took them off and flooded both with Tri-Flow.
Silence once again.

Andrew R Stewart 

Change or service one aspect at a time. Use different shoes, pedals. Replace chain. Remove and reinstall the seat and post. Go on around the bike. have a friend ride next to, behind you, in front of you to listen and help pinpoint the location. Andy.

mark2810

I would've thought rear hub as well. Weird that it's intermittent though..
What kind of squeal is it? Like dirty disc brake low squeal or sharp nails on chalkboard high squeal?

The problem seems like it's occurring under higher amounts of pressure. I would think pedals. I would shift onto high gears and do as Andrew said. Try to pinpoint.

bici_mania

I did a 30 mile out and back last night and had my friends listening for that sound but they couldn't pinpoint with certainty. The person right behind me thought it came from the rear wheel as I think but the person riding next to me thought he heard it came from the cranks/bottom bracket.

Of course because we were all listening for it, it only occurred once. One of them was riding with a knee injury and so the pace was much easier and as a result I was mostly spinning much, much easier gears. So there does seem to be a connection to tougher gears/higher pressure.

The sound is a very high, screechy sound, sort of like the nails on the chalkboard screech. I have hearing loss so it sort of seems to me like the sound is tapering off when it could possibly be going up in pitch. What I hear last for a second or so.

When I had the rear wheel off and in pieces I did check to make sure the axle and skewer were straight which they were. I scrubbed the cassette clean while it was off and it still looks mostly knew with plenty of life and no discernible issues. I am going to take the chain off, check each link for movement and for any links that look like they may developing issues.

Andrew R Stewart 

By separating the function of each of the parts that make the bike one can often find the source of noise. Coast in vs pedaling. Standing vs sitting. No handed vs hands on bars. Right leg down or left leg down. Weight forward over the ft wheel or butt behind the seat. With bike on stand remove the chain from the cranks and test the crank's spin, slop, roughness, ring's tightness. Same for rear wheel, without chain on cogs. Check chain for wear/stretch. Check der pulley wheels for spin and lube. And so on.

If one has a handicap of hearing, vision or tactile ability then that's when a shop would be of help. Andy.

Blue Belly

Headset?
bb?
skewers?
chainrings?
stem?