Air France and Luggage question

You're absolutely right in your thinking. When flying with multiple airlines on a single trip, it's wise to adhere to the strictest baggage requirements you'll encounter along your journey.

In your case, since Air France's carry-on luggage size restrictions are slightly smaller than Delta's, you should definitely plan your packing to meet Air France's requirements because it seems like some airlines are cracking down more.

This way you won't face any surprises or need to check your bags at the last minute during your transfer to Naples. It's always better to be on the safe side, especially when trying to keep things smooth and stress-free during international travel.

Safe travels to Paris and onwards to Naples!

You are correct. For carry-on bags, you always need to look at the most restrictive flight in your itinerary (and also the airline that actually operates that flight, even if it's a code-share) and abide by their limits - or risk the consequences.

Nobody scrutinizing carry-on bags at the Air France gate in Paris is going to care one bit about what was or was not allowed upstream in Birmingham or Atlanta or anywhere else by any other airline. The only thing that counts is the standard they apply for that specific flight as you board that flight. It definitely pays to be aware of every flight leg's requirements throughout your journey, and follow the one that's most restrictive.

The flight from CDG to NAP is operated by HOP! Airlines, on behalf of AirFrance, on an Embraer 190, a smaller regional jet aircraft. Overhead compartments are adequate, but not as large as the large B787 or A330/A350 for the transatlantic portion.
I don't know when you are traveling, but currently there is one daily flight to NAP which departs over 4 hours after your arrival at CDG. With that kind of layover I wouldn't be too worried about my luggage not transferring on time at CDG, therefore I think you can safely check in your luggage and not worry about the carry on requirements.

We are flying at the end of April and the layover is I my 1 hour 50 minutes. That is a small concern and a reason why we are trying for carry on luggage.

We fly Delta a lot and when flying within Europe or on to Asia or Africa, we have flown Air France.
We have never had a problem when our flight started in the USA and continued on past CDG airport.

However, once we had a return AF flight from Heathrow to CDG and then to the USA and we discovered the more restrictive carryon requirements. I don't remember exactly what it was, but I think something like 12 KG per person. We had to check one of our carryons for something like 40 pounds.

1 hr 50 min layover at CDG is not long at all then. But if there are later flights they’ll bring you the luggage at the hotel in Naples if the luggage arrives with the later flight.

It's not so much the smaller size of your allowed carry-on on Air France -- it's the much smaller weight allowance that you will really have to pay attention to in order to meet their standards. Twelve kilos for your personal item and carry-on combined.

We are going to practice pack in a couple of weeks to see about our weight as we knew the weight limit might be an issue. We are in Italy for two weeks and know there will be some laundry to do, but we just prefer the thought of carry on if at all possible. Pre-covid, we would have never thought of just trying this as carry-on but it seems there have been more luggage problems since the pandemic. Two years ago our son got married in London, so we checked some bags as we were going to Ireland for a week after the wedding, but we carried on our wedding clothes and a few outfits. Luckily, all arrived at the same time we did!

Agree with the comment by Kim about baggage weight. On our flight on AF they had someone roaming the hall where people were waiting for boarding to begin and selecting people to have their bags weighed up at the counter.

Checking a bag is not a sin, it's a choice. We check bags on almost every trip, and in decades of air travel, only once have I had a bag fail to arrive when and where I did (that was on a short domestic business trip), and my checked bag arrived on a later flight and was delivered to my hotel just a few hours after I got there, no drama, no big deal. I think I got 10,000 miles as compensation, a deal I'd be happy to repeat often. Granted, I would have had more skin in the game if I was flying half-way around the world (on a route without almost-hourly shuttles) and if I was about to hop on a ship just hours after my arrival (but you can calibrate/mitigate your risk based on such details).

Now, it's certainly true that bags do get delayed, and yes, even occasionally lost. Especially during "airline meltdowns" during peak seasons in overwhelmed airports (I haven't heard about one of those for a while now, thankfully - have we maybe made it through the winter season without a holiday/snowpocalypse meltdown?). But odds are, your checked bags will have an uneventful trip to your destination, and if you have a decent bag, exercise some common-sense packing limits, things should work out. (I know, I know, there are lots of good, valid reasons to go carry-on only, if only to simplify some things and encourage a bit of self-discipline among us packrats).

Point being: If you are really struggling to manage staying within the size and weight limits for carry-ons (which seem to keep shrinking like seat pitch), don't beat yourself up too much if you find that you are happier checking a bag. Maybe get some AirTags and don't fret too much over them.

Yes, those weight limits can be a shock when you run into them. (Cargo pants with biiiiiig pockets, my friend, cargo pants...)

If you are concerned about your cabin luggage width, I have been travelling on Air France for years with cabin luggage that is about 38 cm wide instead of the 35 cm AF requirement, and I have never had a single issue with that. I would not buy a narrower suitcase just to meet AF specs.
Weighing luggage does happen from time to time, though, so mind those 12 kg.

We are flying at the end of April and the layover is I my 1 hour 50 minutes. That is a small concern and a reason why we are trying for carry on luggage.

I’m in CDG right now waiting to fly to Naples. I flew in from Miami on Air France. The flight was on time. It took me about 75 minutes to get to the Naples flight gate and I didn’t waste any time and didn’t get lost. I have tons of Air France miles so I was curious about how much layover time I can play with in the future. I think less than 2 hour is risky.