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mwhatley
07-24-2014, 02:53 PM
Hi everyone,
Lately, I've noticed a somewhat-subtle yet annoying sound on my bike that I can't seem to figure out. I've taken it to a few shops in the area but haven't really got a consistent answer. My best guess is that it's an issue with the chain (but I don't think the chain is too tight). Other theories involve problems with the chain line, size of the chain or not enough lube. Still not convinced it's anyone of those things so I thought I'd turn to the forum. It definitely doesn't impact my riding and it's honestly not that loud, I would just prefer a more silent ride! Check out the short video I took just yesterday. Any ideas??

https://dl.dropboxusercontent.com/u/17407/BikeSound.mp4

paulg
07-24-2014, 03:12 PM
Tricky one. I know you said you didn't think it was chain alignment but have you checked it using the following methods? Measure from center line of chain to center line of bike frame at the cranks and again at the rear hub, the measurements should be the same. Or stand behind the bike and look along the chain to see if the rear sprocket is lined up with the front chain ring. If it's off you can either change spacers/washers (if it has any) on the rear wheel or change spacers (If it has any) on the bottom bracket. Rear wheel option is easier.

However, if the bike just started making this noise it's doubtful the chain alignment is the problem as that won't change over time.

Did you lube the chain to eliminate that option as you note in your post?

Have you tried changing the chain tension to eliminate that option? Perhaps less tension?

Sorry I'm not much help.

vvill
07-24-2014, 03:51 PM
I would guess lube/chain wear first, but I'm not really experienced with FG stuff. Maybe try detaching the chain and spin the wheel by itself, and then the crank by itself - that might narrow it down.

n18
07-24-2014, 03:57 PM
Guess #1: It sounds like there is a screw loose inside the wheel, and it's rotating with the wheel, creating the noise. The rim is long and aerodynamic and has an empty space inside. It could be one of the nipples that hold the spokes fell off inside and created that noise. Did you do any flat repair, or rim tape replacement recently?

Guess #2: Bottom bracket. Regular bottom brackets last about 500 to 700 miles before making noise, but it depends on a lot of factors. Sealed bottom brackets last thousands of miles. This is easy to proof with a multi-geared bike as you can rotate the wheel without rotating the cranks, but not with a fixie.