I purchased the ortlieb 15L panniers from the trek store I bought my allant8s from. Just enough space for me but I wish I went for the 25L instead. Keep in mind since it's a solid fork on the allant 8 front panniers are also an option if you need lots of space.What panniers are you running on your Allant rear combo fender/rack (I think they're the same on the 8 and the 9.9)? I've got an old Arkel bag that I love, but the elastic cord that holds the J-hook is too long and it doesn't clip into the rack tautly.