Singlespeed & Fixed Gear - my 16t free wheel cog

question about my single speed cog, i rode ~90km yesterday and it rained on me a few times. The road i took is close to the sea, though it's a bit above sea level, but when i was riding through the rain, i think i got sand in my free wheel cog. it kinda makes a slight grinding noise and is not as smooth as it usually is, anyone know how i can fix this issue??? when i look at my chain it has a bunch of sand in it, i do not know how to take it off (finding the master link is hard :(), so i wiped it down with a rag, re lubed it. wiped it down again and lubed it once more with pro link gold lube. i tried to get the lube in between the free wheel cog. any advice would be great

here is the path i rode, there and back: http://maps.google.com/maps?f=d&saddr=S%C3%B8borg+Hovedgade+%4055.731640,+12.519700&daddr=Frederiksborgvej+%4055.723130,+12.529220+to:Emdrupvej+%4055.722070,+12.545190+to:O2%2FTuborgve j+%4055.726640,+12.576070+to:152%2FStrandvejen+%4055.744380,+12.583045+to:152%2FStrandvejen+%4055.78 7987,+12.591187+to:152%2FRungsted+Strandvej+%4055.867785,+12.550342+to:152%2FNy+Strandvej+%4055.9856 70,+12.551090+to:1%2FHavnegade+%4056.038140,+12.613010&hl=en&geocode=12514844498768666375,55.731640,12.519700%3B17079306247780546344,55.723130,12.529220%3B107751 82399813079320,55.722070,12.545190%3B7767347517299045471,55.726640,12.576070%3B4345925567361531162,5 5.744380,12.583045%3B6954844578041786055,55.787987,12.591187%3B7594825533579880186,55.867785,12.5503 42%3B12418467738069661709,55.985670,12.551090%3B8587993818312946764,56.038140,12.613010%3B1168722815 402285211,56.090221,12.498603%3B15702446025748898761,56.122940,12.299260&mra=ls&sll=55.915352,11.832275&sspn=1.320643,3.537598&ie=UTF8&t=h&z=10

Taking apart and rebuilding a freewheel is a huge PITA. Live with it, buy a new one for $20, or buy a ENO with replaceable sealed bearings for $80.

Hey, I'm originally from Landskrona, right across from you. That looks like a nice ride.

You can treat the freewheel as a disposable object and leave it alone, or spray some WD-40 or other water repellent in there...the sand will probably eventually work its way out.

My strategy with cheap freewheels is mostly just to leave them alone...they do tend to develop a gritty noise after riding in slop, but if you just leave it alone and don't muck it up with lube, the sand eventually falls out. The bearings inside freewheels only move when you are coasting. As a result they don't rotate under huge loads that other bearings are exposed to so they don't tend to wear as rapidly. I have been using the same cheap ACS, Shimano, and Dicta freewheels for years and have yet to have a malfunction.

alright, cause i was wiping down my whole frame after my ride, and there was a build up of oil and junk around my free wheel cog, so i wiped it clean (flossed it) between the wheel spokes and cog-itself with a baby wipe. after that ive been hearing this gritty sound and have been putting an excessive amount of prolink gold lube on it. so the sand/dust between my chains will work itself out also?