Originally Posted by
Often1
The problem you face is that DL is quite specific in its definition of dimensions, e.g., those include handles, wheels and anything else protruding. Manufacturers usually do not include those protrusions and that leads to problems at the sizer. The best approach is to use a measuring tape on the case and not rely on published dimensions unless they specifically limit the way DL does (which most brands don't).
This has nothing to do with the sizer. I am specifically talking about carry-on for CRJ-900. My Briggs Riley bag fits fine in sizers and on overhead on regular sized aircraft. But now that I am flying regularly on an CRJ-900 route, I would like to buy a smaller carry-on to temporarily use to avoid gate checking the bag.
You are right about manufacturers not including protruding areas of bags. I am not all that interested in going to a luggage store, and would prefer some real world examples. A luggage store is going to have a limited selection, I last bought a suitcase in a store 20 years ago. It is a bit crazy to me in an online shopping world, manufactures all lie about their true bag dimensions making online shopping difficult. There is no retailer anymore who would have all the available models on display to physically measure.