With a north of England autumn on the way I decided I needed some extra carrying capacity. During the summer I can ride with very little baggage but when the temperature drops it's good to have some extra room handy to store warmer clothing and a heavier grade waterproof jacket. Usually I ride with an Ortieb saddle pack and a small 'bar bag but neither of those can acommodate much more than lightweight summer clothes.
Enter the Rixen Kaul Freepack City Backpack with a capacity of 18 litres. It's larger than I need but then I don't have to fill it to the brim! The backpack is fitted with Rixen Kaul's Klickfix attachments which means it can be mounted on the bike via their handlebar bag bracket. The bag has various comparments that are ideal for storing clothing, food, tools, camera and anything else that you care to carry. It also has two mesh side pockets which are perfect for drinks bottles.
I tried it out on the front of my Swift using the R/K Caddy bracket then moved it to their seat post adaptor. On the front it was stable and easy to keep an eye on. The steering was a little heavier but most of the weight came from the drinks bottle! However, if you are a weight weenie you would not be riding a folder, one of the new gravity defying exotic machines would be your first choice. Obviously, on the front it presented a little more air resistance but no more than I did. When I moved it to the seat post the steering returned to normal and the bike felt a lot more balanced. Being a rucksack the bag is very easy to remove and carry off the bike - handy for a folder. If you fold the Swift on a regular basis and use the seat post to hold it all together then the seatpost bracket will not be an option for you. I only fold the Swift when I put it in the car (about once or twice a month) so it is no problem to lay the seat post beside the bike.
All in all I like the backpack. It provides good capacity and looks neat. Folding bikes are different compared to the "normal" machines and require alternative solutions to luggage problems; the Freepack City Backpack fits the bill for me.