Cornbread2, do as you please--
It's your pistol, and your anatomy and your motorcycle.---
BUT--An anecdote might be interesting in this regard. Sorry, I can't quote the source. It was a first-person account, the guy signed his name. I can't personally vouch for him, but it SOUNDS plausible.
He was riding his m/c on desert roads with his .45 holstered, chambered, hammer down, under a light jacket. He met another vehicle and got to the right side of the road with brush whipping his right handle bar. Loud
POP sounded and he felt a burning on his right hip. He stopped and discovered that his .45 had discharged in the holster. Bullet went out the open bottom, barely grazed his buttock cheek, and did some minor damage to the 'cycle. Of course, the empty had failed to eject fully.
Apparently a branch of the bush slapped the hammer spur hard enough to bring it back
ALMOST to the "half cock" notch, but not catch on the sear. This is plenty of hammer fall to allow the mainspring energy to cause a strong enough hammer strike to send the firing pin to the primer. Said he found bark in hammer serrations. Happily, the angle was such that the bullet did little damage to either his sittin'-down place or his noble steed.
The frame tang is designed to protect the cocked hammer from any impact from the rear.
Drizzt and others suggest carrying an empty-chambered pistol, cocked and locked - - - I can understand this as a confidence-building exercise, but it sure cancels some of the benefit of going armed. Let's see--Draw, knock off safety,
THEN slingshot the slide to chamber a round, acquire a shooting grip, take aim and fire?
As an alternative, let me suggest chamber empty, hammer cocked, safety OFF. Check pistol frequently. Hammer will stay back, even with thumb safety not locked. And, if the pistol is needed for defensive purposes, it cam be chambered without delay. Also, hammer back makes it easier to cycle the slide.
Best,
Johnny