cprobertson1

Good morning folks!

I've got a mystery creaking sound that I can't seem to track down, which is synced up with the power on each stroke, but much more noticable on the left stroke.

I've had a look at Sheldon Brown's page on mystery-noises but I've not had much luck tracking it down yet.

• Occurs at any gear combination, suggesting it may not be the chainrings (being a cheaper set, they are welded and riveted together as well)
• Louder under heavier loads.
• Starts with the left pedal downstroke, and progresses to both pedal strokes as power is increased.
• Doesn't appear to be caused by the chain rubbing against front deraileur (I'll pop the chain off and confirm that tonight)
• My best guess is that something is up with the crank set - grabbing the left pedal and pulling perpendicular to the axle causes the creaking.
• The pedals themselves don't seem to be the cause, as I can cause the creak by pulling on the crank arm.
• My second-best guess is that the bottom bracket has been overtorqued and loosening off/reinstalling it will help

Things I'm going to check tonight unless anyone has any better ideas:

1. Remove left crank and look for signs of wear
2. Check for creaking by applying force to the axle directly with no crank
3. Remove right crank and chainrings and repeat step 2
4. Remove, clean and reinstall bottom bracket (it's a new bottom bracket with <400 miles on it)
5. Repeat step 2 again
6. If it persists, install a different bottom bracket and repeat step 2 yet again
7. If it persists, look for cracks in the frame

Does anyone have any other suggetsions on what it might be and how I might go about testing and fixing it?

canklecat

Check the simple stuff first. Like the chain, cassette/freewheel cogs, rear derailleur pulleys, etc. Even if they appear clean stuff can get lodged in crevices -- a pebble or twig -- and cause a regular thunk with every pedal stroke.

I've sorted out pesky thunks just by poking a stick between each chain link to dislodge debris, as well as between each cog, and removing the rear wheel to inspect the inner facing rear derailleur cage plates and pulleys. Often bits of tough grass, string, fishing line, etc, wind around a pulley and that stuff is almost invisible unless I remove the wheel and checked with a flashlight while wearing reading glasses. Sometimes it's a bristle from the cleaning brush I used last time! Or shredded Scotch-Brite abrasive pad torn off the sponge and wrapped around a pulley axle.

Amt0571

If your BB is press fit, my guess is it'll be the BB / frame interface. I have 2 press fit bikes: one started to creak after 18 months, the other one creaks like mad since new. This can't be solved without removing and reinstalling the BB (and replacing it, as they're not supposed to be reusable after removing), or replacing it with a thread fit one. I'm planning to buy a thread fit BB for my mountain bike as it drives me nuts. I'll probably keep my road bike BB for a while as it's not that bad yet.

In any case, reassemble the chainring bolts and the crankset with a bit of grease. I have had creaks come from this 2 places before. Make sure it's not the seatpost or the saddle too. Try riding a short distance without the seatpost to be sure.

cprobertson1

I can't do much right now as I'm at work - just popped the chain off there and I believe I've narrowed it down to the crank set. It's a UN-55 BB, and pushing/pulling either crank arm causes the creaking, even with the chain removed. Since both sides are coupled via the axle, that makes me think either the cartridge is failing (unlikely) or its a little loose in the frame. It's also possible that both crank arms are loose and creaking, but I find that unlikely. As you said, seatpost may be to blame as well - if the frame is flexing when I apply force it might be creaking. I'll pop it off tonight and see how things go.

If it is a loose BB, I hope the threads are alright =/ It's been cycled about five miles so far and will need another 2.2 miles to get it home from work; alternatively I can leave it here and bring all my tools in tomorrow... which doens't sound very fun.

Amt0571

If it's a square taper BB, dissassemble the cranks and remove the BB. Assemble it again using a bit of grease on the threads and crankarms. It's also possible that the BB has loosened itself and it's moving inside the frame shell. I've had that happen before. If you can't feel the movement when pedalling you won't have issues cycling 7 miles with a slightly loose BB. I have cycled more than 50 miles with a loose BB where I could feel the movement and threads were ok when I was able to tighten it.

dsbrantjr

DO the easy things first. Try swapping your pedals with a known-quiet pair, preferably platform type to eliminate shoe/cleat noise. Clean and grease both male and female threads first.

cprobertson1

Will do!

I ended up procrastinating last night - I'll get right into it tonight though!

andrewclaus

The left side BB "adjustable" cup is often plastic, and sometimes there's a few mils of play between it and the cartridge. It's unlikely there's any shell damage. This happened to me once and I fixed with with a shim made of foil chimney tape.

_ForceD_

I’m a +1 for BB being loose. Recently two of my bike had a “creaking” that was resolved by simply snugging up the BB (both sides).

That being said ... I had a friend who once had a “ticking/creaking” issue. Finally discovered it was his heel hitting the excess front derailleur cable and it flicking against the frame.

Dan

Retro Grouch 

"Creaking" says "bottom bracket" to me too. If you bought that bike to me, I'd pull the bottom bracket re-grease the threads and torque it back into place. Dsbranjr's idea to replace the pedals with a "known quiet pair" is another good idea..

cprobertson1

My moneys on the BB as well. I can get it to creak with no pedals or chain by pulling on the crank arms at various angles - just about to take them off and get all up in the bottom bracket. Will report back either later today or early tomorrow depending on whether I get it sorted 😆

cprobertson1

Dissassembled and cleaned everything, got it all back together... and it seems to have gone... There was a bit of corrosion where the adjustment cup goes on the other side of the cartridge BB, and a bit of evidence that its been rubbing. There might have been a little creak when I pushed on it again after reassembly - I'll find out for certain tomorrow morning

--EDIT--

All sorted! Another ten miles on the clock and we're all good. As I said, if it returns my first suspect is the left-side cup on the cartridge BB, so I'll follow up on the advice of @andrewclaus and add foil tape.

The "little creak" I heard last night was caused by the chain flexing sideways when I applied force to it - it had ended up in a crosschain configuration when I reassembled it, but it sorted itself out as soon as I started pedaling and shifted into a straighter-chain configuration.

So, knock-on-wood, that seems to be it solved!

Thanks for all the help everybody! Much apprecaited!

cprobertson1

... The sound's baaaaaack!

Going to tape it up per @andrewclaus' suggestion in half an hour during the lunch break and report back. If that fails, I'll take a heavy-handed approach; start at the top and narrow it down, simpler-to-complex things as you guys suggested.

I'm still confident it's bottom-bracket related though, since it went away then came back again!

--EDIT--

I am now reasonably confident it's the threaded cup that goes on the left side of the cartridge on the bottom bracket (or the left crank). Adding a strip of aluminium tape to the inside of the cup sorted the creaking more-or-less instantly. Its still possibly the left crank (maybe I've overtightened it or had it on-and-off too many times) so I'll check that by taking it off an reinstalling it if the noise comes back (without touching the BB).

mackgoo

When you worked on the BB you must have had the rear wheel off? I struggled with a creek for a while, a while ago. It sounded like it was coming from the bottom bracket. I disassemble, assembled to no avail. It ended up being the rear QR. I put a little grease on the threads and drop outs tightened and solved.
Your play issue may really point to the BB, but it does seem every noise comes from the BB regardless of where it really is.

cprobertson1

Not a bad idea - the rear wheel hasn't been off for about a month.

It's a bolted axle rather than a quick release, which, incidentally, is why it hasn't been off for about a month! It's due the monthly deep-clean though - so what I'll do is push that back by a week or two to see if the creak returns - at which point, if the diassembly/reassembly of the rear wheel and axle fixes the problem without me touching the bottom bracket which will help to rule it out as the source of the noise.