backpacks?

Do you really need 55L for 9 days? If you're going to carry that much, then you definitely want the padded hip belt (which RS bag doesn't have). I would encourage you to watch some light packing videos, whether from RS or just by searching on YouTube. There are lots of ways to reduce. Also, there are lots of packable daypacks on the market. Can also be your "personal item" on the plane. Most don't have any padding in the shoulder straps, though.

Take a look at the Allpa35 from Cotopaxi. It's sold as a bundle with daypack, shoe bag, etc.

Most hotels will hold bags for you, and there are luggage lockers (or left luggage counter) in most train stations.

TY G3 I will look into that bag.

I use a Pacsafe Venturesafe 45L, best travel pack I’ve found. Instead of a day pack I use a pacsafe vibe 325, it’s smaller & easier to to use in crowds. Hope you have a great trip!

On my April trip, my wife was in a wheelchair. I purchased an Amazon Basics backpack carryon for $48.99, and it worked out great. I pushed her in a lightweight travel wheelchair and towed her 21" rolling carry on at the same time with no problem.
I still prefer my Travel Pro ultra lightweight swivel wheel carry on to a back pack bag, however. And I refuse to check a bag.
read:https://www.amazon.com/AmazonBasics-Carry-On-Travel-Backpack-Black/dp/B01J24H2K0/ref=sr_1_2_sspa?ie=UTF8&qid=1543149937&sr=8-2-spons&keywords=backpack+suitcase&psc=1

If you intend to carry on your bag you may want to double check the Fairview’s dimensions and the airlines size limitations. A 55L bag may not fit. You may want to look into the smaller 40L Fairview instead.

TLS Motherlode Weekender convertible Junior from Ebags. On sale right now for $69. Go to the website and watch the video to see if this would meet your needs. I really like mine and it’s flexibility.

eBags.com

Wow - 55 liters is a BIG bag! That's a camping size bag for sleeping bag and small tent. There are many good bags out there. Some are mentioned above. Get a 40 liter bag. If you are a big guy - 45 liters maximum. Try to keep with the 40 liter size. (Better for airplane bins). You can easily buy a "packable" day pack - many options available. (i.e. RS Civita, Eddie Bauer stowaway, etc.)
Packing cubes (I like ebags.com - Ebags Classic cubes in bright - easy to see colors - best.). The cubes will really help with the packing. Roll your clothes into little logs and line them up in the cubes. Makes a big difference.
Ebags etech line is good. I have an old ebags Etech pack that is going strong. Ask more questions as you need info..

55 is too big. A 40 litre would be better. Osprey Porter or smaller Fairview, TLS Motherload. Padded hip belt. Plan to do some sink laundry. People travel the world in just 40L.
Embrace the manbag. Cross bodybag would fit the bill. Check out Tom Bihn products if flush for cash, and Timbuk2 classic messenger bag isa well recommended option. I typically don't recommend messenger bag designs as there is no zip on top, but this one is designed to deter pickpockets.
Many train stations have luggage storage, hotel maykeep it, but if a small mom and pop, it might just be a closed wardrobe in the front hall. Decide what your comfort zone is for safety. Also, now an app for businesses willing to hold luggage. Here is an article.
https://lifehacker.com/how-to-stash-your-luggage-for-a-couple-of-hours-when-tr-1823620766
More have been designed since thensodo some more reading. You may want to post a question on the TripAdvisor travel gadgets forum(or search it) for reviews or recommendations of storage apps.

Mentioned above - Ebags is having a fantastic sale now. Can't beat any of the Ebags travel packs for quality/cost. Get either the Motherlode regular or junior depending on your body size or the etech 3.0 pack which is in-between the other two for size.
This is a great sale and pick up some packing cubes while you're at it.

You're planning to use this bag for carry-on luggage? Have you looked at Lufthansa's carry-on restrictions? Not only dimensions but they have a weight limit too (8 kg, I think). They did weigh bags that looked too heavy on my last trip with them. That being the case, the Rick Steves Classic bag (which I use) has the real advantage in low weight (2 lbs). Its also on sale now and I think a real bargain at $64. I just traveled with the Cotopaxi Allpa 35 ($190), and really liked it a lot, but it is a bit smaller than the RS Classic and is a bit heavier.

If you think you need bigger, like the Osprey 55, I'd just check it.

For hiking backpacks a load carrying suspension system which transfers a significant load to the pack's hip belt is critical. For a hiking (or ski touring) backpack, study the REI expert advice on picking and fitting a backpack. Note that matching pack size to your torso length is critical if you want the hip bolt/suspension system to work properly. If you have a long toro, the proper backpack size will likely bo too long for international flight carry-on size limits. https://www.rei.com/learn/expert-advice/backpack.html

But it sounds like you are really looking for luggage. In that case, a suspension system with hip belt is not critical or even essential for getting you luggage to and fro. A number of international airlines limit your carry on bag's weight/mass to 8 kg (about 17#), well within the comfort limits of resonably fit males. A plus of a RS Classic is its light tare (empty) weight allowing you to pack 15# of stuff. Full suspension backpacks with internal frames weight significantly more. A full suspension backpack is only needed if you are doing real trekking.

As others note, European hotels generally are good about holding luggage before and after check in.

Perhaps get an Exofficio or Scottevest/jacket [or vest] with the inside zipper pockets, which could lighten your backpack load.
I won't travel without mine!

Y’all should take a moment and look up the Osprey—55L is the total volume of the two bags when zipped together. And that’s about the same as using a 35-40L main bag and a 15-20L backpack. BTW: The Farpoint is the men’s version of the Fairview.

https://www.osprey.com/us/en/product/farpoint-55-FARPNT55_526.html

Osprey makes fabulous gear and their wilderness backpacking heritage shows in all of their products. You probably don't need bombproof construction or the heavy duty suspension system. I can’t help you on the locker question but the Rick Steves travel backpacks and eBags units are highly regarded for this type of travel. As long as you’re not carrying your pack up the Alps, you should be fine with one fo these far less expensive bags. Study the packing lists published here. That's the hard part.

Unless you are an experienced backpacker I would encourage you to consider a rollaboard that will meet the airlines size and weight restrictions. Many people in our age bracket who take up carrying a backpack find their musculoskeletal aches and pains emerge or are magnified. Don’t risk ruining your vacation.

Many people in our age bracket who take up carrying a backpack find their musculoskeletal aches and pains emerge or are magnified.

For a 60 year young male (or female) without obvious physical limitations, walking with a backpack shouldn't be ruled out before giving it a try. It is a good idea to do some training ramping up to your target walking distances before your big trip. Here are some exercises to get into shape for your walkabout: https://www.sierratradingpost.com/blog/fitness/backpacking-exercises/

To increase your endurance and make your mileage on your trek a little
easier, I simply recommend mimicking your trip!

Start small, in regards to both mileage and load. If you're going to
be hiking 12 miles on your backpacking trip, slowly add on mileage to
your hiking each weekend to build up to nine or ten miles.

Then, start adding load to your endurance training. However, I don't
think it's necessary to train with a 50 pound pack on your back.

Backpacking puts strain on the core, the upper back, the shoulders,
and the legs. Naturally, it's important that all of these muscle
groups are strong and prepared.

However, it's also important to work on muscular balance when training
for a backpacking trip. When backpacking, it's easy for our posture to
suffer, caving inward at the chest, allowing both our upper and lower
back to take quite a beating. I've put together a few backpacking
exercises designed to work the muscles used most while backpacking.
[See article for detailed strength excercises.]

I'm another person who really likes a waist belt to distribute the backpack load, such as on Rick's Convertible Carry-On (sale price $79.99) or my old, long-wearing Eagle Creek model. But if you're tall (like Rick), then this strap may not hit anywhere near your waist. Factor that in, or try on bags, if you can.

Many people in our age bracket who take up carrying a backpack find their musculoskeletal aches and pains emerge or are magnified.

As someone in that age bracket I must disagree. It’s less about the pack and more about what you take. Overpacking means aches and pains whether it is packing or rolling. It’s also important to look at the suspension system for the pack. A cheap or poorly designed suspension will lead to aches.

As previously stated, Lufthansa has a strict weight limit on the main bag (hint: put the heavy stuff in the personal item). A lighter backpack helps you make that weight.

When I first started carry on travel I had a combined pack like the Fairview. I wasn’t happy because neither the large nor small pack was optimized for what I wanted. The big pack was awkward when the little pack was attached. The little pack had limited features for a day bag. I went over to a true travel pack and a cross body purse (like a messenger bag) and found that to work best for me. Nowadays I just do personal item travel. But that’s a later challenge.

I also think 55 liters is ginormous. Find a good and light daypck for dayhikes and a regular bag for luggage. I like the Patagonia 22 l lightweight travel tote. Other favorites are the Osprey daylite pack or the Deuter Speed Lite 20. The suspension wire in the Deuter pulls out and you can wad up the pack for storage.

Frankly, for a 9 day trip you should be able to get everything inside a single pack. Pull the daypack out to make weight limit but after that travel with a single pack. Or even consider traveling with a 35 liter pack. You’ll be happier for the type of trip you are planning.

And may I introduce you to Snarky Nomad? He’s got the type of travel you want nailed down.

TY All for your more than informative replies. As always, so much to consider.

Personally a 55L backpack would be way too easy to over-pack and wind up too heavy IMO. Osprey has a 46L (the Porter 46, which is also available smaller - the Porter 30L) that is a carry-on size, hide-away backpack straps, and has nice compression sides.

I have been using the SOC Gear Bugout bag since 2015 and it is currently on sale 30% off at ebags: https://www.ebags.com/product/soc-gear/bugout-bag/227517?productid=10112410

That bugout bag is made by several different manufacturers. It's a nice, simple bag, and expandable. I got mine on Amazon for $30. My only caveat is that the expandability feature can lead to overpacking, so I have to watch myself.

At 5 lb 12 oz the SOC bug out bag weighs more than my Rick Steves rolling backpack!!!!

That’s an outrageously heavy bag considering it’s a backpack. It’s a really poor choice for anyone traveling on a weight limited airline like Lufthansa. It takes up 1/3 of the weight allotment.

I'm in your age group and I carry a 33L backpack, packed weight no more than 15 lbs, and it doesn't seriously aggravate my physical issues (knees and minor back). I don't feel I can use a shoulder bag as my personal item anymore because my right shoulder has been the occasion for 2 orthopedist visits, 2 rounds of physical therapy and then finally had to have a steroid shot. When using public transportation from airport, I use the backpack and a purse as my only items, and do the sink washing thing.