Paul, a few thoughts:
> multi-tool: I've found that most multi-tools are relatively heavy. But: Filzer make a very tidy, light & compact kit with a ratcheting handle and 6 or 8 insert bits. You can set aside the not-v-heavy rigid plastic case -- I use a Ziploc bag. Gerber also have a well-made light & compact multi-unit, with pliers, knife, etc.
> tubes: I've found that Schwalbe's XXL are light (~95 gms) and very good quality.
> tires: You may not need any just now, and we're in trade-off territory in any case. The fastest & lightest I've ever used are Compass tires. Mine are the 26 x 1.8 Naches Pass with standard casings. (There is an extra-light). I've found them fast-but-fragile. Maybe they'd suit for your Audaxes, but you might lose on the tube-changing swings whatever you gain on being quickly over the road.
> camping gear: More trade-offs here, as you probably already know, and personal preferences too. (As the saying goes, "Cheap, light, durable. Pick any two.") New-generation gear and clothing can be light, durable, and of course pricey. It's also less bulky, and that's also desirable on a bike. On tents: The best combination of weight-space-ventilation-compactness-quality which I've found is my current Tarptent Moment DW. It's also reasonably priced, at around US$300. I bought the optional nose-to-tail crossing pole, and have found it invaluable, at the cost of another 6 or 8 ounces. (This converts the tent to sorta-free-standing, and ensures that the fly doesn't sag against the mesh inner.) Doing it all again, I might buy the two optional carbon poles, instead of the standard alu -- sometimes, I find that the alu hoop pole in the centre, the main structural part of the tent, binds on the fabric channel into which you insert it to pitch the tent. Another detail point on tents: as a rule, the length of the bundle when wrapped depends on the length of the segments in the poles. That determines whether you must mount the tent on a rack, or whether you can tuck poles and fabric separately or together into your panniers or a frame bag.
> sleeping bag, mattress, etc. One variable is: how much rain do you expect? In damp conditions, a sleeping bag with the new variety of synthetic fill might be my choice over down. You do have a slightly heavier bag as a result, but the new synthetic fills are much lighter than the older ones.
> luggage: Given the notes above, and that you have a light ti rack, I'd suggest Arkel Dry-Lites (or similar) as rear panniers, and frame bags elsewhere. On handlebar bags: There's an outfit in Massachusetts, Dill Pickle Gear, which makes a lovely bar bag,
but I'd have to pay at least Cdn$300 just to save a pound. Here's the link, just in case:
http://www.dillpicklegear.com/store/ (I think I'll opt for a Ground Effect rain jacket instead--same cost/weight calculation.)
Hope that's helpful, Paul, and enjoy the continuing arithmetic
Cheers, John
