I use my Lululemon Ta Ta Tamer for my triathlons. They bolt down my C-D cups (depending on time 'o the month) and I have no chafing or hot spots even after a swim/bike/run.

For cycling only, I will wear a looser Ta Ta Tamer and not cross the straps. Sometimes I wear the padding in them, sometimes I don't. Depends if anyone will have a camera and how thick my top is. ;-)