The following is a guest post by Yisroel Bas. He blogs at אומשלאָף.
This past spring I decided that I wanted to start wearing tsitsis, at least on Shabbos. This decision came out of an embrace on my part of biblically-based Jewish symbolism/self identification. However, I was not attracted to the traditional undershirt variety and I wanted something a little more special. So I designed a T-shirt style beged to wear on Shabbos. I chose blue ribbons to match the color of tekheles. Although it took some time, I convinced my mom to make it for me. I wanted the garment to be as square and shirt-like as possible, and a preliminary look at the Torah yielded no problems with my design.
When my mom finished the garment, I spent an afternoon figuring out and eventually tying the tsitsis (Ramban Teymeni style). I was really happy with the final project and decided that I would wear it for the first time at Yugntruf‘s Yiddish Week retreat. While there, several people asked me why I had tsitsis on a shirt with closed sides. I was told that the majority of the beged needs to be open in order for it to be khayev tsitsis. I asked for the source of such a rule and was met by a lot of “I’m not sure”s and “gemora”s. After the retreat I started on a journey to find the source of this “rov beged” injunction. I would walk around on Shabbos with the shirt on and go from shul to shul asking the rabbis if my beged was khayev tsitsis. One told me that the source as Manakhos in the Gemora. Another had no clue. And yet another was convinced that as long as it has daled kanfes, it’s khayev tsitsis.
the completed begedI went home, found a translation of Manakhos, read it, and found no mention of “rov beged” or even the slightest hint of a definition of kanfe. Finally the Chabad Shliakh in my building found the injunction in his Shulkhan Orukh, but he did not know where the Shulkhan Orukh got it from. Finally after asking the shliakh at my school a million times to look up the source, he put me on the phone with the chief librarian at the Chabad library. He found the source: the students of the Maharam of Rothenburg (d.1293).
Okay, so my shirt is fine according the Torah and Gemora, but not the Maharam (nor anyone who thinks that the Shulkhan Orukh is from Sinai). On top of my own doubts and uncertainties, I now had several rabbis telling me that I can wear it all I like, but just not on Shabbos (because if the beged isn’t khayev tsitsis, then I am “carrying” them about when I wear the beged). I’ve been wearing it anyway, partly because I like how I feel when I wear the beged, and partly because I am not sure of how much the Maharam and what he supposedly taught matters to me. For all I know the beged is khayev tsitsis in that the majority of the beged is open (sleeves and bottom), just not contiguously. Right now I am getting ready to make another similar beged and I think I’m going to stick with “closed” sides.

ראה הפֿקדתיך היום הזה על־הגױיִם ועל המלכות
זע, איך האָב דיר געשטעלט הײַנטיקן טאָג איבער די פֿעלקער און איבער די מלכותן
לנתוש ולנתוץ
אױסצורײַסן און אײַנצוּװאַרפֿן
ולהאביד ולהרוס
און אונטערצוברענגען און צו צעשטערן
לבנות ולנטוע
צו בױען און צו פֿלאַנצן