alt131 - 7:32 am on Feb 27, 2012 (gmt 0)
Hi Skier, good question, and I can't find any guidelines for post widths either - probably because most lines (bar those without white-space) will usually wrap. Occasional one fails even though there is white space - the one above is a good example - and I've been unable to establish a pattern or possible cause. I only make an adjustment if the thread has been pushed very wide and code samples are a challenge - again the above is a good example as it hasn't wrapped at ideal points.
So I wouldn't get too concerned about counting characters, or trying to insert hard returns to create precise line lengths, but yes, around 80 is probably a comfortable reading width.