The first rule of bicycle touring is to never do a tour on new equipment. That means everything that's coming along on the trip should have been your bike for at least 200 miles. I can't emphasize how important this is! Even if the equipment is fine, if you haven't gotten used to it the results can be disastrous. As an example, a couple from the Western Wheelers bicycle club went for a bike tour in the California mountains 2 years ago for a wedding anniversary celebration. To celebrate their long time marriage, the husband bought brand new touring bikes for both of them. On a big descent in the Sierras, the wife lost control of her new bike and for some reason could not brake. She crashed against a rock, fractured ribs, leg bones and was cut up badly ending the tour prematurely and leaving her an invalid for more than half a year. After the crash, the husband took the bike to several bike shops and no one could find a single problem with the brakes. She crashed simply because she was unused to the bike!
Since I ride 100 miles a week, typically that means 2 weeks before a trip I put on new chains and new tires if appropriate, as well as new chainrings and cogs if they are worn at the time. I make sure that the two weeks before the trip I use the bike for commuting and recreational riding. If I have panniers I mount the panniers on the bike and ride with them. Get used to how the bike behaves uphill and downhill with a load. You'll be safer and become a stronger ride for it. If you need an overhaul for your bike, do it a month before you leave in case there are parts that are hard to get.
First of all, there's no need to buy a new bike for the trip. Most people can happily tour on the bike they currently have. However, many modern bikes sold won't take wide tires or fenders, so I feel compelled to say something. The best bicycle for this trip will probably be the Rivendell Rambouillet: a long wheelbase sport touring bike with clearance for 32mm tires with fenders. Other bikes that could work well include the Bianchi Eros, the Trek 1000C, and the Bianchi Volpe (none of them are as well thought out as the Rivendell, though!).
I recommend using slick Avocet 700x25 tires --- slick tires throw up less dirt in the rain, and grip better both when the road is wet and dry. 25mm tires should be sufficient for most surfaces for those whose body weight is under 180 pounds. If you weigh more than that consider going with 28mm tires instead. (Please note that most tire manufacturers other than Avocet tend to size their tires smaller than advertised --- if you buy other brands of tires it is generally advisable to go one size bigger) Avocet tires are hard to find, so if you are willing to buy mail order call Harris cyclery and ask for the special googler 10% discount. There's no need to get the Kevlar version. They're just expensive and add rolling resistance. Last year we got lucky and toured all 930 miles with no flats on Avocet 700x32 tires. If you're bringing a mountain bike put Avocet 26x1.25 tires on the wheels. They work real well!
Before you leave, pump up the tires to about 115psi. If you're using 700x25s, that will be the last time you need to pump up the tires for 3 weeks unless you have a leak. (Make sure you have NO leaks before you put the bike on the plane. Having flat tires is a good way to damage your wheels!)
For wheels, I recommend traditional 36-spoke wheels with normal rims. The fancy low-spoke-count wheels look nice and may be lighter but are in no way field repairable! Since I've built my own wheels I'm quite capable of repairing wheels in the field, but because low-spoke-count wheels get their strength from tensioning the spokes to an ungodly amount, there's no way I can do that in the field. In fact, when those wheels break, typically the only recourse a bike shop has is to send the wheels back to the manufacturer for repair, in which case you'll end up having to buy new wheels during the tour. You might as well save yourself the hassle and get normal wheels in the first place. Whether you put fenders or not on the bike depends on your comfort zone. In general, fenders are very nice to have on long rain rides, but if a lot of off-pavement work is required then fenders can be more of a liability than an asset. We will stay on paved roads most of the time, with one or two off-pavement excursion when this will allow us to bypass lots of traffic or give us outstanding scenery. Note that if you end up using a raincape for rainwear, you MUST have fenders on your bike or your raingear will be worthless!
Rather than use panniers and racks, for a high mileage, high altitude gain tour like this I recommend using saddlebags along with either a saddle that can support them, or a saddlebag support. The best saddlebags currently made are probably the ones made by Rivendell Bicycle works. They are incredibly spacious, and made of great material, and are designed so well that they don't sag even when very little has been put into them. Their big drawback, however, is their cost: their largest bag will set you back $145! For those not so wealthy, Carradice has been making saddlebags longer than anyone, and their prices are quite reasonable, though with the newly strengthened pound, not as incredibly cheap as they used to be. I have used the Lowsaddle Longflap and the Nelson Longflap for years as a commute and overnight trip bag and I love them. Their drawbacks are that they are not as capacious as the Rivendell saddlebags.
If you're tall enough (at 5 foot 10 inches, I'm just tall enough that a fully laden saddlebag won't sag, but a lightly loaded one will sag onto my tire, and I've got holes in my saddlebag to prove it), you won't need any support at all for your saddlebag. Otherwise, you'll have to buy a saddlebag support along with your saddlebag.
Gearing: make sure your bike has low enough gears for 17% grades with a load! Probably the steepest road we'll climb is Grosse Scheidegg on the way to Grindelwald. It's one of the most pleasant roads I've ever ridden, but was steep enough that we had to walk a few hundred feet on it with our tandem. I personally run a 24x34 as my low gear, but if you're strong, a 30x28 isn't out of the question.
Important: If your bike has STI I recommend that you swap them out for either downtube-shifters or barcon-shifters. Both of those shifters have a "friction" mode that you can switch to and continue riding with ease if you either bend the deraileur hanger or the deraileur goes out of adjustment. Last year, we had a frayed derailuer cable that was slowly dying on our bike during the tour. We discovered this about 6 days into our tour, but all we had to do was to shift the shifter to friction mode and we rode the remaining 13 days of the tour with no problems. With STI it's off to the nearest bike shop with you, and if you jam your STIs (which has been known to happen) then you'll have to buy a new set of STIs at European prices (which are expensive). In the mean time, replacing cables on bar-end shifters is a half-hour job (and I've done it, and will carry spare cables). If you have an STI-induced mechanical failure then you're on your own!
Lights: We won't ride in the dark, but many alpine roads have tunnels in them and you'll feel better if you've got both a front a rear light on your bike (note that in some countries both front and rear lights are legally required, though I've never seen this rule enforced). Vista-Lite makes a number of good ones, as does Cateye. Just get some lightweight battery lights. The LED ones are fine for tunnel use.
For keeping stuff dry I recommend Reynold's Oven cooking bags. They come in turkey size and half turkey size. Use the turkey size for clothing and the other sizes for organizing sundries. Stuff sacks are expensive by comparison and aren't fully waterproof, while Reynold's bags are cheap and very strong (so they are reusable for your next tour). Our Reynold's bags have survived 3 or 4 years of touring before we lose them. (and yes, you can bake a turkey in them too)Personal
I suggest that you just do what I do --- go to the airport with the bike, buy a bicycle box ($10-$25), and put your bike in it. All you have to do is to remove the pedals, and set up the handlebars so that the bike fits in the box. If you have an old-style quill stem, loosen the stem bolt, and lift the entire stem off the bike. If you have a newer style aheadset style stem, remove the front panel of the stem and lift the handlebars off. Make sure you screw the panel back or you might lose the face plate of the stem. I recommend taping the handlebars so that the bulge faces right (which will protect your rear deraileur). Then put the bike in the box. The entire procedure will take about 15 minutes, and your fenders and rack will stay on the bike. I have travelled this way for the last 10 years and have yet to have any damage on the bike that wasn't caused by me.
France, Italy, Germany, and Austria all use Euros. So of course the Swiss have to have their own currency, the Swiss Franc (how quaint). In practice, however, Swiss establishments will take Euros. :-) I may have a large Euro-denominated CD I can cash out and trade for U.S checks with relatively low transaction costs, so if that sounds attractive to you let me know.
For a tour like this, it is imperative to start training early. The Western Wheelers Bicycle club has a Long Distance Training (LDT) series of rides starting in early January going all the way out to June. If you start with the C series of rides you should be capable of doing the Sequioa century by June, which is about 100 miles and 8000' of climbing within 10 hours. If you can do the Sequioa and still feel good at the end of the ride you're in shape for this tour. In fact, you should be able to do the Tierra Bella which is 4000' of climbing in early April. I co-led the LDT series last year for the Western Wheelers and it's got beautiful rides in it so attend as many as you can.
Sometime in March I will organize a "dry run" to Pigeon Point lighthouse from Sunnyvale. There's a youth hostel there ($15 a person), and we'll stay overnight, so this will be a test of your luggage carrying setup. (The route over there goes over some dirt as well, so you'll get some additional dirt training) The round-trip is about 100 miles and 6000' of climbing, which is about half the climbing we'll expect to see in the alps.
Fortunately for the human body, cycle touring is one of the few endeavours where you can expect to get stronger as you go from day to day in riding, provided you eat well and get enough sleep. I have yet to finish a tour in a shape worse than I start one, so don't let the mileage and altitude numbers scare you off!
I can't emphasize how important this is. We will be facing descents where your speed will 40mph. Learn how your bike behaves in high speed, learn to use your brakes. If your grip is weak or likely to tire get a handgrip exerciser tool and exercise your handgrip! We will occasionally ride through heavy traffic and it would be invaluable to learn to ride under those conditions as well. While Switzerland, Austria and Germany have bike paths, France and Italy won't have them. The Swiss and Germans are incredibly polite drivers, but the French (who are competent cyclists and drivers) will absolutely not stand for a silly cyclist meandering all over the road, so learn to ride in a straight line and keep to it. The Italians... Well, they'll do whatever they want to do, so stay calm no matter what.
For mild-off pavement work (which we will do once in awhile if we use bike paths in Switzerland, which tend not to be paved), you can practice on fireroads. The Los Gatos Creek trail or the fire road between Montebello Road and Page Mill road is a good proxy for what we will face in Europe.
It's nice to be able to speak the language. A little bit of French and German will go a long way in dispelling the "ugly american" image and make daily life easier. Learn to say please and thank you. Berlitz sells language courses on tape so you can learn to count (a nice thing to be able to do) and ask for a room. Since some of you will likely be stronger than I am, it would be nice if the first ones to get to town start looking for places to stay.
Mid-to-late June is perfect for bike touring. Most of Europe hasn't started on vacation yet, and the Tour De France crowd hasn't shown up yet. I expect us to not need reservations except for weekends (Fridays and Saturdays) which will require a bit of extra planning. Don't expect to go vegetarian anywhere in Europe, however (and don't try to get by on an inadequate diet while on a bike tour as you WILL regret it).
The two companies that offer pre-paid SIM cards are Sunrise and Orange. Both require you to supply your own phone, which should be a GSM, unlocked world phone. Both will have booths at the Zurich airport. If there's anyone in the booth who speaks english, get them to change the phone menu over to English for you. (It can be done, but apparently it's buried deep inside) The minimum starting fee is 50 Swiss Francs, and refills can be gotten later. Note that incoming calls are free, but outgoing calls are charged.
The Half-Priced ABO card costs 200 Swiss Francs, and will grant you 50% off on all Swiss Trains, and 25% off on all German and Austrian trains. Apparently it'll pay for itself with one round trip to Geneva and back, so it might be a good deal if we take a couple of train transfers.
We basically have two choices: we can do the Swiss-Italian Route (described by Jobst Brandt in his Tour of the Alps) or we can do a train transfer from Zurich to Geneva and ride south from there, and make our way back to Switzerland through Italy. The advantage of the former route is that I'm somewhat familiar with it, and it does show off some of the nicest parts of the Alps first with polite Swiss drivers. It also provides a bit of time to get in shape since after the initial climbs there's a bit of a long flat section through Italy. The disadvantage is that I don't like Italy, and I've been to that area before, so the novelty isn't there for me. Nevertheless Jobst's got the tour down to a science and knows where all the good places to stay are.
The advantage of a train transfer to Geneva is that we get to start right at the French border in the French Alps. The disadvantage is that with no warm up period we'll be hitting the big mountain passes right away.
In any case, please express your preference for the route ahead of time, but be prepared for a last minute change of plans. Basically, the more rainy it is, the more likely it is that we'll head south right away towards warmer weather. And of course, if there's a headwind there's nothing like hopping on a train and then riding from the other direction. :-) The point is to have fun, not to race or wear ourselves out everyday. (Though for some of us, that may well be our idea of fun :-)