Bicycle Mechanics - Freewheel "knock" ?

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View Full Version : Freewheel "knock" ?


TheDL
12-11-06, 07:04 AM
Can a bmx freewheel make a knocking noise if it's going bad?

I know the noise is not the valve stem washer or my hub out of adjustment. The knock isn't constant though. If I back pedal the cranks with my hand, it's hard to tell, but I think I feel a rough spot. But it could be the chain doing that too. I want to place blame on the freewheel because it's an el-cheapo Dicta, but it hasn't been ridden in any bad weather. The chain is fairly new and I don't think it's the BB because it's fairly new and Ultegra level so I don't think it'd give out on me this early. This is my first BMX freewheel though so I wanted to just ask if it's possible for a freewheel to make that sort of noise.

Did that make any sense? :o


tool boy
12-11-06, 07:33 AM
Cheap freewheels can make all sorts of noises and problems. I like ACS freewheels. They seem to last, come in good sizes, and make a lot of noise when coasting (I like them, the people I ride with don't). If you have the cash, White Industries makes the best freewheel available. :)

mactheknife68
12-11-06, 08:26 AM
"Knocks" can be caused by anything from a dead spot in yer pedal stroke (the freewheel pawls slam when engaging), or maybe youve over-tensioned your chain. Check your chainline, too. Overly tight spots and a bad chainline are likely culprits.


pahearn
12-11-06, 10:59 AM
You have to take the chain off of the freewheel to definitively put the problem sound on the freewheel -- you may be following the wrong path. I'd take the chain off and see if it feels/sounds funny alone, then I'd take a chain whip and use it to apply cranking force on the cog to see if you hear/feel anything weird while the freewheel is being stressed, sans drivetrain.

EDIT: Another thing, check the tightness of your chainwheel bolts. When they start loosening up they can sound as though you have chain/cog issues, when really the problem is up front.

-pete

TheDL
12-12-06, 09:28 AM
Thx for the tips guys. I hadn't thought of the chainring bolts pahearn, good call.