My old Carradice saddlebag has seen better days so I have invested in a Carradice Super-C saddlebag and an SQR quick-release device. The trouble is that I don’t think it’s a good idea to fit such things to a carbon seatpost. Carradice thought it would be OK but Thorn deprecated the idea.
I bought a new seatpost at Richardson’s Bike Shop but removing the old seatpost was, as ever, a real fight. It took two of us, one holding the bike and the other wielding two hefty screwdrivers which had been clamped where the saddle rails normally go, about 10 minutes’ sweating and grunting to shift the thing.
I have put plenty of lithium grease down the seat tube, but the consensus seems to be that, although this is a good idea, it’s necessary to remove the seatpost, ot at least, move it around, every few months to avoid it seizing. It really is a difficult job, even for two. Single-handed, it would be a nightmare.