The dreaded rattle. That annoying creak. A squeak that doesn’t seem to go away. There are many, many noises that a bicycle will make. I can live with howling brakes because I know how to quiet them, but having that knock or rattle that is a mystery will drive me insane. I have been known to not ride a bicycle for months until I find the cause of some strange disquietude. I will try to help with a little insight on some common places for snuffing out the din.
Quick Releases - No joke. I have solved a host of bicycles simply by lubing and tightening the wheel QR’s. Certain skewers are worse than others. A super easy but hugely overlooked cause.
Valve Stems - Not only do the stem nuts loosen while riding, but if those nuts are not used, the stems can rattle in the rim. Make sure they are snug, but don’t crank on them. And make sure to tighten them after pumping to your optimum riding pressure.
Headsets - I am guessing that close to half the bicycles that go through my workstand have loose headsets. Usually not super loose, but just enough to be annoying. A good way to know is roll the bike up vertically onto the rear wheel, pick it up and bounce it. That low buzzing rattle is the fork steer tube vibrating in the head tube. Make sure all that play is out of the headset but it still rotates freely. Can’t seem to find a sweet spot, it may be time to replace it.
Stem/Handlebar - Over time, the metal that is clamped around the fork (or within the fork) and the handlebar will essentially soften. This causes the bolts to have lower torque than when originally put together. Contaminants can also creep into the interfaces all of which can lead to some of the loudest creaks on a bike. Simply disassembling these parts, cleaning them, applying a light film of grease to all threaded fasteners and optionally on the interface of parts will usually cure the noise. Be sure to check for cracks and apply proper torque.
Bottom Bracket - The granddaddy of them all. This is an extremely common place for the power groan that often comes with every pedal stroke. Today’s bicycles are moving away from the traditional threaded frame to bearings that just rest inside the frame itself. Any deformation of this part, will lead to noise. The first place to start here is to remove whatever contains the bearings of the bottom bracket, clean, lube/loctite, and reinstall. On threaded bottom bracket shells, I use Loctite Anti-Seize. I have pulled bottom brackets out after 5 years and who knows how many miles and it looks like I did the work yesterday. Toxic, but it has made my job a lot easier. While messing around with the bottom bracket, check the pedals to crank arms and the chainring bolts to make sure all are tight.
If after all of the above a bike STILL is making noises, there may be something wrong with the frame itself and probably worth a trip to your local mechanic. Seat tube inserts, bottom bracket shells, stays and all manner of parts can loosen and start moving under normal riding. It is rare, but is why warranties can come in handy. But don’t overlook a mischievous mechanic dropping a ball bearing or two inside a handlebar. Not covered under any manufacturer’s warranty.