I'm nearly 6 foot height yet my torso length is considered small at 16.5 inches (42cm) by all the rucksack manufactuers. It's not like I'm lanky, either, in fact I have a proportional leg to back ratio, or at least I think so?! Is there any way to measure yourself to determine if you are long in the back or legs? I may just go to the local cotswold tomorrow and get measured with the proper tool however I'm sure my reading is accurate because I made my partner repeat it 5 times to be sure.
The proper way to measure is from the biggest bone at the back of the neck to the top of the hips, not the base of the spine!
According to Crux my torso length is too short for even their size 1! I think the manufacturers have got the sizing completely wrong because they explain and even have diagrams showing how to correctly measure the torso yet when describing their sizing designations they use the phrase "back length" not "torso length" which is completely different. I'm confused!
p.s on my lowe alpine civilian ruck and lowe alpine military issue rucksack they both fit me best when the adjustable back system is adjusted to the highest webbing loop, i.e the longest back setting. I'm confused!