Q. The straps of my tefilin are only about ten years old. On the tefilin shel yad, at the top place, where it ties over the biceps and goes around the loop of the kesher, since I place them tight, the strap has shrunk a bit. Is the retzua still kosher? Even if it still has the right width, the fact that when I tie it on the arm, it is all bent and curved by the loop, is that acceptable?
A. The minimum width of retzuos is about 11mm according to the Chazon Ish (Kuntres HaShiurim 7), and about 10mm according to Rav Chaim Noeh (Shiurei Torah p.274: 37).
Horav Shlomo Miller’s Shlit’a opinion is that if the retzua meets the size standard at the loop kesher, the fact that it bends is the natural and common way of securing it, and is acceptable.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a