I am slightly bemused by all this rack chat. My bag just hangs from the leather loops, onto the saddle mounted QR thingy. If I want it to not swing fore and aft, I do the other leather strap up round the seatpost. That's all.
Not much, really. The bags often sag down and interfere with the rear wheel or get in the way of other things, but if it doesn't happen to you then a support rack won't really do much for you.
I am slightly bemused by all this rack chat. My bag just hangs from the leather loops, onto the saddle mounted QR thingy. If I want it to not swing fore and aft, I do the other leather strap up round the seatpost. That's all.
What am I missing by not having a metal frame?