Luggage on Tokaido shinkansen

Hi,

I'm already familiar with the rules regarding the oversized luggage on the Tokaido shinkansen, but I have a couple of very specific questions.
Our party is made by two people, and we both have luggage that is sligthly below the 160cm threshold, and we would like to not buy the last row reservation, mostly because we don't want to have to reserve very much in advance. But:
1) I remember that the overhead space in shinkansen trains is not that big, would a 70x50x30cm suitcase fit?
2) the rules say no more than 160cm in total and never specify anything about the single measures, but I've seen images of measuring "boxes" in stations that clearly check for luggage not bigger than 30x50x80cm. Now, my friend's luggage exceeds both the 30 and the 50, while still being less than 160cm in total... Are we going to get measured and have to pay the extra charge?

Thanks!

If it is wider than 50cm, then if may pose an issue. As it may overhang the upper rack by some decent amount.

The length (longest side) of a suitcase doesn't matter too much as a case will go lengthways into the upper rack.

You can google pics of suitcases in the upper racks. Heap overhang. Just for yourself against the many examples online.

Someone correct me if I'm wrong (because I'm an extremely light traveler), but I think your 70x50x30cm suitcase would fit under your legs, as long as you keep your legs on top of the suitcase and refrain from using your foldable table. If you're lucky enough to have space, you can sit at the seat next to your suitcase's non-reserved seat (if you know what I mean).

Or, you can forget about getting a seat, and stay at a deck where you can put your suitcase on the floor and sit on that suitcase. A lot of locals do it.

The one thing you should not do is to put that suitcase on an isle. A lot of "Johnny's" fanatics do it when traveling to their idols' concerts, and it's so annoying.

I also happened to come across the following website. The 2 on the left are free-of-charge and can be placed on the shelf for big luggage.
https://travel.watch.impress.co.jp/docs/news/1204283.html

The following images may also give you a hint.
https://www.google.com/search?q=%E6%9A%91%E3%81%9530cm%E3%81%AE%E8%8D%...

Yes, I have seen the size guides in stations with an indication on a maximum of any one dimension, but all the online advice from the different JR companies focuses only on the total.
You can (of course) keep the case on the floor, and not all over-head racks are designed the same. The E6 ones are tight (because of the ceiling design), but the E5 or E7 have more space. Most people would be on the N700 series (or variants) and they can take large cases as they accommodate up to 43cm high cases.

Thanks for the replies!

Now I have a mental image of Johnny's fans occupying the aisles which is somehow pretty funny to me :D

Looking at images and going with what JapanCustomTours said, it feels like there should be enough room, but also we have alternative possibilities.

Thank you!