Just back from seeing the daughter studying in Italy (oh, and co-incidentally riding with mates for 2 weeks in Tuscany, as you do) - things seem to have changed with the airlines flying to Europe. My observations -
1.. Used to be able to get an understanding that sporting equipment (skis, bike etc) were in addition to usually allowed baggage limits - that's now history - had a forthright exchange of views with the Cathay check in person in Sydney and got off (lightly as it happens) with an extra $250 excess baggage charge). [censored] about that until I found out my mates on Malaysian airlines get hit for twice and three times that. I was a bit over the weight limit but they were about 10kg over (not hard if you are packing for a few months over there).
2.. Seems when travelling to Europe the carriers have decided to enforce the (self imposed) limit of 32kg for cattle class passengers - a bike in any sort of hard case will just about use all of that up. They even include your carry on baggage in that 32kg limit.
3.. I suspect that's the airlines trying to recover some margin where the profit on the ticket prices is now marginal or non existent at best; - they will offer to send baggage over the weight limit as unaccompanied baggage at a lesser cost but that gets there a good few days after you do, so it may not suit. At check in time you don't have a lot of options other than [censored] and then paying.
4.. Curiously, the 32kg "absolute" limit miraculously becomes 60+kg on routes to the US - same aircraft, same baggage holds, and double the limit - bless the obese ones but that is a little lacking in logic n'est pas?
5.. British Airways are talking about lowering(!!) that 32kg limit to 20kg on all their flights, without reference to the length of the journey.
6.. Got called to the security desk re-boarding the flight in Hong Kong and frog marched down to the baggage handling area and asked to open the bike box and explain the presence of about 4 of those little gas bulbs used for a CO2 inflator. My understanding was that anything inflammable and pressurised or an oxidising agent (which inert CO2 clearly isn't) was prohibited but that didn't phase these guys - gas bulbs were confiscated and consequently I developed a much closer attraction on the rides to those in the bunch with frame pumps. I have always just included those little cylinders in the luggage on flights in Oz and never had a problem.
7.. I guess that means places like HK can x-ray scan baggage down to that size of item (which probably is a good thing), except they need to calm down a bit about things like sparklets bulbs used by cyclists. Oh well, there is no sacrifice too great to make in us all fighting godless global terrorism and preventing Al-queda from getting hold of those cylinders and then turning our water fizzy.
8.. Thinking I might avoid the problem on the way home I enquired about posting clothes and gear no longer needed - italia post (and apparently most other European post offices sell 10kg prepaid postage boxes for about 40 euro which is a way better deal than the airlines give you - they say it will get here in about 4 to 6 weeks.
9.. Still a big fan of the $15 Qantas bike box, so long as you pack the bike well and use lots of bubble wrap etc - the outside of the box gets a bit ratty after going through a few airports but a cheap and good solution IMHO - esp if you securely duct tape some small luggage castor wheels (Bunning's sell em) to both bottom corners of the box.
10.. On returning to Oz with a bike you are an automatic candidate for the red line (goods to declare) so they can ask you if you used the bike on any farms and picked up any Euro dirt - didn't seem fussed about roadies but mtb riders are likely to get asked to pull the bike out and show there is no dirt or mud on the bike or wheels - I am not madly enthusiastic about cleaning the bike at the best of times but with 20+ hours of jet lag a full clean of the bike in the customs que could be very tedious - I think a very fulsome clean before you pack the bike would be time well spent for our fat tyred friends.
11.. Tuscany is all either up, or down - pretty, but don't expect to recover on flat sections - there aren't any!
best, Andrew