[Shiversolitude]

I have a Charge Plug Grinder, single speed commuter bike. Its a 700c commuter. I have a driving me crazy, noise coming from the drivetrain when I ride and I cant put my finger on it.

Every time I ride when Im pedaling theres a chug chug chug pause chug chug chug sound it goes in threes, pauses and then does it again. Its more of a knocking, or chugging sound.

Ive checked my wheels for loose spokes, checked the chain for tight spots, it does it regardless of chain slack. Ive looked very closely at the chain sprocket and freewheel teeth and cannot find any frozen links or broken, or bent teeth, I checked the hubs, they appear to be ok, not too tight or loose. I took the pedals apart and greased the bearings again.... its still doing it.

Does anyone have any idea what could be causing this? Its only doing it under load when pedaling... wont replicate it on the repair stand.

 

[gonefirefightin]

brakes rubbing? wheel bearings shot? bottom bracket? hard to tell without seeing it

 

[clarkenstein]

my guess is you have either a bottom bracket issue or your chain tension needs some adjusting.

 

[Shiversolitude]

I thought it was chain tension also, or a stiff link.. but Ive tried loose chain, and really tight chain, and normal chain and its still doing it. I guess BB or freewheel is the only remaining options.

 

[w00dy]

Take this to a shop. Mystery noises are hard to diagnose when looking at the bike. You"re only going to get wild stabs in the dark here.

 

[samnation]

Have a mechanic ride next to you they'll be able to tell you what it is no problem.

 

[cjcrashesalot]

I have this same exact noise, it's rhythmic for me too. Mine is most prevalent under heavy load, but sometimes disappears completely for no apparent reason.

I have an entirely new drivetrain: Cranks/BB, chainring, chain, wheels, and freewheel.

Definitely hard to diagnose. My thoughts were either chainline or crappy freewheel, but my chainline seems good and it's an ACS freewheel.

My other thought was that it could have something to do with the gear ratio. I'm running 48/16, which is exactly 3:1. If there was a slight problem with anything in the drivetrain, the fact that the same chain pieces are hitting a certain spot on the chainring/freewheel over and over may exacerbate it.

If you find a solution definitely post it, I'm curious.