Originally Posted by
chasm54
That's true. But with a bagman support and a Carradice or similar saddlebag, load is effectively being borne by the saddle and seatpost. Admittedly the weight distribution is different, and I wouldn't want to load up that saddlebag with too much gear, but for ultralight touring it's absolutely fine. I've done some quite extensive credit-card tours in this configuration on a road bike with 25mm tyres, and been entirely comfortable.
Agreed, I did most of my fast touring on road racing bikes in Ca. without tent or mess kit. Poncho, camp pad and sleeping bag on rack with small handlebar bag suspended between brake hoods on drop bars. 28mm tires were my training/touring tires. Now I'm a fat old phart not going fast anywhere and 35mm are preferable.