Diagnosing Rattles in Bike

[apple]

I have a really annoying rattle on my bike when I'm on terrain that is anything but totally smooth. Maybe it's coming from the bottom bracket, maybe the front wheel. I'm gone over the whole bike and made sure everything is tight and there is nothing loose. It's a single speed, so no derailleurs, and older steel frame. Can't seem to locate the rattle, it's persistent and constant as long as I'm on any bumpy surface. Any tips to diagnosing this?

[dustyrider]

Is it part of your kit or attachments you add for a ride? No joke I’ve chased down the zipper on a jacket, and a jersey, only after months of poking around the bicycle. Admittedly the jersey was much quicker because I had the jacket face palm already under my belt.

[tuxbailey]

Last time this happened to me I took out the BB, made sure nothing is in the shell, reapply anti-seize and the noise went away.

[apple]

No, different kits worn with same problem.

I'll tear apart the bottom bracket I guess and see if that helps.

Is this something that a loose spoke could cause? None of them seem loose to me, but maybe one is just slightly loose.

[bjf]

Bottle cage bolts?

[Ken Robb]

The frequency (HERTZ) of the sound may give you a clue. High-pitched tinkles come from smaller, thinner parts. Clanks and clunks come from heavier components. I've found a few noises caused by little bits rattling around in my rims. Then I got too old to hear such high-pitched sounds over the general hum of my tires and I quit worrying about it. :-)

[thunderworks]

Do you use those small screw on nuts on your inner tube valve stems to hold the valve stems tight? If the nuts get loose they can rattle.

[Kontact]

Valve.

[ultraman6970]

This, or you have a loose headset.

Originally Posted by bjf

Bottle cage bolts?

[joev]

Rattles are tough... Quick summary of things to check:
- bottle cage bolts, dab of grease.
- nut on valve stem at rim, or just take it off...no need for it.
- if disks, disk brake pad/weak clip or loose bolt of brake. New clips/pads
- check calipers or cable against frame on caliper. Add frame protection tape.
- are cables rubbing/close to frame? My Cannondale cables open between the bosses and is so close to the downtube that it rattles against the frame on very bumpy roads.
- loose nut that holds ss cog/or loose spacers on rear hub-just add grease
- something down seat tube. Take out post, flip bike and shake.
- loose headset/spacers. Light grease on spacers/then tighten
- brake cable clips (no shift cables, right?) ...use zip tie instead of clip to hole cable on boss
- brake lever - bolts, lever itself loose, nut covers loose - check tightness of nuts.
- part of seat. Fizik has bag clip that, if no bag, can rattle.

[apple]

Thanks for the replies everyone. I feel like the sound is coming from the bottom bracket, front hub, or up to the headset. That general "region" of the bike.

Square taper bottom bracket, Phil Wood. I removed the plugs and made sure things were tight, but I don't have the tools to remove the BB itself, or the crank arms, so can't do too much there for now.

Checked water bottle bolts, had recently installed a new water bottle holder. Those were fine, guess I can throw some anti-seize on them though.

Checked all cables, nothing seemed to be rubbing. All bolts on front brake (Campy Chorus) were tight.

Steel fork with star fangled nut. Loosened everything, added a spacer above stem, just in case the top cap was contacting the top of the fork (it was close if nothing else) and not letting it tighten, then tightened it back down, then the stem bolts.

Turned the bike upside down and shook everything, no noises or rattles.

Just installed a new saddle and removed the seatpost, plus put in carbon grip compound and tightened everything back a couple days ago and still makes the noise (the latter because the seatpost was slipping a little). That's all tight.

No cap or nut on the tubes, and the presta valve top was tight before I rode last, checked that for sure as I've had that issue before.

Biggest potential candidate in this round was the top cap not letting the headset tighten. Made sure to tighten everything before my last ride, so maybe adding a spacer on top of the stem will be the ticket.

Next round is to, I guess, remove the fork and shake it in case there's a piece of an old star fangled nut in there or something? Any other suggestions?

[TDot]

Bottle cage bolts or B.B. for me those are the first two most likely culprits