I'm hoping one of you framebuilder, master mechanic, bike whiz types can help me out. After a particularly sandy ride today I pulled my S&S coupled bike apart to drain any water and re-grease the threads on the couplers. In doing so I noticed that the coupler on the downtube has a really gritty feel (and sound) when you rotate it. It doesn't seem to affect getting a hold of the threads on the other side of the coupler during assembly and tightening it down feels smooth and normal. But when open and I spin it around, it sounds like there's a bunch of sand in there. The top tube coupler is smooth and silent. Any tips for cleaning this out, or is it nothing to worry about?
Thanks in advance!