After doing a bit of on-line research, I opted for the Revelate Designs 14-liter Viscacha seat bag, which is commodious and easy to set up. I have, however, discovered the bag has a slight tendency to fishtail when I'm out of the saddle and really pounding the pedals. Notwithstanding this small drawback, I am quite pleased with the Viscacha and would recommend it to others.
