I must have an underwire in my bras (sports or regular) to keep my 'girls' seperated.  This bra does the job nicely.  I wore it on a 1/2 hour bike ride the day I got it (without washing it first) and noticed that the fabric was pretty stiff.  However, after only the first wash, it feels much better and is much more comfortable.  The back is akward though, so that does get some getting used to.  I usually end up putting it on backwards (without my arm through the holes), clasping the three claps, turning it to the right side and pulling it up/putting my arms through to get it on.  Because of the weird design, I gave it 4 stars instead of 5....just a tad combersome to put on, but otherwise a great bra for a larger chest.  But please note that for those of you who might care, it is only lightly lined and any headlights will shine through.