TexasCHLforum.com

I registered just to answer this question!

Several years ago (before the recent Open Carry laws) I called my local police department to ask if it were legal for me to transport a rifle that I'd just purchased, on my motorcycle. The very helpful officer informed me that was (and still is) perfectly legal to openly carry a firearm in/on your motor vehicle, including a motorcycle. HOWEVER, if a patrolling officer thought that I was brandishing it, or if it frightened people, then I might be arrested for Brandishing a Weapon, or some kind of Disorderly Conduct.

So, as is often the case, "Is it legal to carry" is rarely the only question to ask. Sure, it might be legal to carry... and you might still get properly arrested anyway.