Today I made my first trip to Smart & Final with the two rear Bontrager panniers that I bought from I. Martin Imports. I had to carefully figure what I could actually haul in each pannier, and I wasn't sure how much weight each could hold. However, I now know that each can hold at least 20 lbs, because in one of the panniers I put two 10-lb bags of flour. I really couldn't have put much more than what is pictured in the panniers... they were full and heavy - about 40 lbs total! But they definitely got the job done!!
Once again, I wasn't really too aware of the extra weight on the bike, except that there is a lot more forward moment on the downhill which means braking needs to start earlier. When I got home, however, there was going to be no way I could force the bike up the front steps of the building, so I had to remove the panniers first. Just too heavy. It makes me think that maybe I should get a cargo trailer for the back, but for right now, I'm good...little trips like this one can do the trick.