Carradice have been around for a long time, are beloved by bearded men on antique steel tourers and I have been warned that saying anything disparaging about this Super C would result in me being pursued to the ends of the earth by gnarly CTC types. That is to say, slowly and with frequent breaks for tea and cake.
Happily I came to love this bag, but it took a while...
Fitting the bag appears to be simplicity itself. Simply attach two leather straps to the bag loops on your Brooks (you *do* have a Brooks, don't you?) and secure the third strap around your seatpost. Having done this you can then admire what can only be described as the Carradice Sag as the bag sits, face down, on your back wheel. If you ride a huge frame then you might, just, get away with fitting the bag this way, but for a chap of average height like me it's pretty much inevitable that you're going to need a proprietary bag support as supplied by Carradice themselves. As I didn't have one to hand and I needed to use the bag for a planned day ride I had to improvise a support bracket with the spare parts I had to hand. It wasn't pretty but it worked, just.
The bag itself is pleasingly simple, with one main compartment and two side pockets. There is also a waterproof inner pocket, handily sized for maps and route sheets. Internal organisation is nicely straightforward and if you insist on carrying extra stuff there are loops on the lid to bungee it on. Cotton duck is water-resistant and breathable, which means that even if your stuff gets wet in a prolonged downpour it'll dry out eventually. Some modern bags might be completely waterproof, but if you put wet stuff into them, it'll stay wet, which isn't so great.
Any load carrying solution is going to be a compromise between convenience, comfort and capacity. Pick any two, as the old saying goes. The Super C scores for comfort (the load isn't on your body and doesn't affect bike handling) and capacity (23l is enough for a credit card mini-tour) but it loses points for convenience as it's not easy to remove from the bike. Commuters will struggle with this bag unless they have the luxury of storing their bike smack bang next to their desk.
The reflective strips down the back of the bag are of the proper, high-quality, stitched on variety. The light loop is also sturdy and tough.
It's an old design and you're almost certain to need a bag support (which bumps up the price) but as a way of carrying a medium sized load on day rides, audaxes or a mini tour, this bag is hard to beat.