I think we have a plausible explanation: older bag versus newer bag.
Jean says:
We measured the length this morning with our two jet lagged engineering brains. It measures 22”. His suitcase is 10 years old. It’s never been handled by baggage handlers and looks in very good condition. Did the RS store reduce the length during that time period?
Lola says:
I believe the size of the RS bag was recently reduced from 22” to 21” to conform to the Euro airlines’ 55 cm requirement, but do not recall the exact year.
I say:
I have a nearly-brand-new Rick Steves Rolling Carry-on Bag, right here (two of them, actually), purchased December 2023 at RSE HQ in Edmonds, during their holiday sale. It is in absolutely pristine condition (it just came home from its first trip, where it never was checked, never was handled by anyone but us).
I just measured it oh-so-carefully and very precisely.
Its length is definitely under 21 inches - it's just a smidge over 20.5".
Since we have two of them, I measured both. There's no discernible difference in length between our two bags.
To measure it's length, I placed it flat on the floor, bottom end butted up against the base of a flat door, and placed a tape measure on the floor underneath it, showing the tape measurements. I placed a thin, flat piece of wood across it's top - this should replicate any "sizer" that's true to square. The length comes in between 20 1/2 inches to 20 5/8 inches, depending how you wiggle and square it up, but in any case it's under 20.75", so true to it's claim of "21 inches".
Unless there are some pretty extreme variations in size due to manufacturing tolerances (which would need to be more than a full inch, which I find hard to imagine), it seems pretty clear:
If you have an "old" version of this bag, it may not pass muster at KLM (or equivalent 55 cm) bag sizers.
If you have a "newer" version of this bag, you should be able to smugly breeze through the size check and roll that thing right onto the plane.
The real question is, When was the manufacturing specification changed?
Perhaps a question for Edmonds on a Saturday...