RPB staff sold me a Fremont pannier, but I quickly discovered the attachments won't allow it to be mounted far enough back on the rear rack to prevent heel strikes, nor does the bottom clip adjust to a position where it can be attached. The RPB staff at my local shop claimed to not have been aware of this. For grocery runs, I'd really like to have a couple of easily-removed panniers on the back of the bike, rather than attaching a basket or (for my needs) a too-small trunk pack. Have any other Expand 5 owners encountered this problem? Are there other brands or hacks that would work? My Ortlieb Backpackers are too large.