Originally Posted by Carbonfiberboy

Ah, you're right: I forgot the spare RD cable. PITA to replace but more fun for the rest of the ride than jamming it with a stick. Also forgot the spare brake shoes we carry on the tandem. It had a bad habit of shedding them. I've used everything on that list several times. That's the reason it's on the list. I put it down to 20 years of doing/leading group rides in the mountains and other backcountry. The object is to be self-reliant and self-contained. I was never one to depend on the kindness of strangers.

You could easily carry your spare saddle in a Carradice. You just haven't looked around is all. I was on a ride with a fellow who broke his saddle rails. He tried to continue standing, but got too tired and had to bag it and wait for someone to some get him. I've also broken a stem in the middle of a ride. However I've never carried a spare saddle or stem. That's a little too much. The weight of the rest of my stuff is negligible. 5 seconds/1000' of climbing maybe? Hard to say - it seems to be too small an amount of weight change for the bike calculators to pick it up.