Your weight logic isn't. But I don't argue that a human can easily be over 200#. Heck, I'm over 200#.
And the lightest adult dragonborn weighs in at 220 (as per the DMG) and their weights go up to 320. They may not be 'large' as a specific game term. But they average 100# heavier than a human.
Just out of curiosity, how fast do you move carrying 140 pounds?
sez you. If I can press 175 lbs over my head, but I can't press 300, it's because I don't have enough muscle. And given what I know about muscle and how and why it weighs several times more than fat, needing another 15 lbs. of it to almost double that figure is pretty close to fact (although looking at this chart now, that'd be the jump from 14 to 18). But really, 18 str is about the average for a D&D fighter (I'd say it's 17, honestly). I can't imagine a PC putting a 14 into their main stat anymore.
I honestly don't know how fast I move, but it's not less than half my original speed. But it also hampers my jumping ability a LOT (because I often do jump squats with 135 lbs strapped on and I only get about six inches off the ground) more than what D&D leads you to believe. D&D strength doesn't make any sense, and it really shouldn't, but stronger people weigh more, and that is a fact. That's all I was pointing out.
I'm not 'slapping on an extra hundred pounds of carrying capacity. I'm making a ruling on a fact that is not in the books, based on given information in order to create a ruling that is consistant with the rules as they exist (including the fact that Rage Drakes appear in the Dragonborn encounter and are mounts according to the MM and the fact that horses are not appropriate mounts for dragonborn - as already noted in this thread).
If I need a justification it would be that their different body shape (more squat, lower to the ground and - very importantly - massive legs compared to the legs of a horse) enable them to carry far more weight. (Horses have very thin legs for their size which is why they are so susceptible to leg injuries such as befell Eight Belles.)
"Slapping on extra carrying capacity" is what you proposed.
I hope you can see the difference.
Carl
No, I can't see the difference, because it's the same thing. I suggested slapping on extra capacity for a horse. You suggested slapping on extra capacity for your drake. You want to pretend like you're not slapping it on because you have "reasons" for why it should be a certain way. I do, too. I think a party of PCs should be able to walk into a town and ride away with mounts, and not have to say "aw crap, the dragonborn is too fat to come along" and also not have to say "oh, there just so happens to be a rage drake corralled with all the horses, and for some reason he hasn't devoured every last one of them". We put the dragonborn on a massive clydsedale and called it a day.
You can't just state your opinion and use that for ammunition in an argument. You literally said "If drakes aren't strong enough to carry dragonborn, I will make them that way, because that's what I want". And while that is totally fine (and I even agree with you), that is certainly not a valid argument as to why I can't do the same thing with a horse.
EDIT: You also claim that these things are "facts", which is laughable. It's a fact that horses are not appropriate mounts for dragonborn? Really? No, I don't think so. It's unlikely as written but it's certainly not inappropriate and it's definitely not a fact.
Shabe said:
Thinking about it I quite like the fact Dragonborn need to go on very strong warhorses or nothing, I think its quite cool to have these noble big strong warriors walk or travel in the back of the cart for a while at lower levels or maybe even for most of their career.
While I agree with you, that's house rules. Horses can't carry dragonborn unless they are exceptionally small, or unless you as DM increase their carrying capacity (which is what I did). So that's not really a fact, it's just a change.