While in NYC recently I spotted a hack that I found both admirable and foolish at the same time. Here is what I spotted -
It's the method of attaching the basket to the seat post rack that is the hack.
And if it is not apparent from afar, there was some serious effort made at mounting the basket to the rack. We are talking drilling holes through sheet metal and using some serious screws.
While I admire this hack, I once did something somewhat similar in the past and the seat post rack ended up breaking. I don't have a picture of the set up I am referring to, however I do have a picture of the box that I had attached to the seat post rack. After the seat post rack broke, I attached the same box to a braze-on mounted rack.
A few months after attaching the box to the seat post mounted rack, the rack broke where the horizontal post was welded to the coupling (if that's what it is called) that fit over the seat post. Maybe seat post racks have improved over time, and readers are more than welcome to comment on the durability of seat post racks in the comments section. If you are looking to haul anything of substance, I would strongly recommend using a braze-on mounted rack - and the sheet metal method of attachment would be a very sturdy method of attaching a basket to a rack.
It's pretty clear the reason the owner of the bike above is using a seat post rack is that the bike does not have braze-on mounts. If that's the case, you can use clamps like these as a substitute for braze-ons:
Or you could actually buy a bike that is meant to have a rack mounted to it =)