How should one tie a tie on Shabbos (or yom tov) so that it doesn't have any knot problems?
In other words there are lots of ways to tie a tie. I was wondering which of these are okay for use on Shabbos.
The strictest opinion is that any knot tied on shabbos has to be able to be untied with one pull. Most ways of tying a necktie can be untied with one pull provided the neck isn't inside the loop :).
One may tie (and untie, not that you asked) any knot that isn't strong and is meant to be untied within twenty-four hours of its being tied. Sh'miras Shabas K'hilchasah 15:52, :55. (However, :58 seems to contradict this.) CYLOR for a final ruling, as always; in particular, SSK doesn't AFAICT indicate what's considered strong.
This may be stretched logic, but: R' Tzvi Sobolofsky said in his children in halacha lecture, that a diaper is a kesher sh'aino shel kayama because it will be dirty and thus removed in less than 24 hrs. This seems to ignore the fact that the same closure, if left alone for 24 hrs would probably stay closed. So the same can be said of a tie. If you are in the habit of weaing your tie for more than 24 hrs straight, this could still be a problem, but what nut wears a tie for 24 hours straight?