This gun is rather bulky and heavy to CCW on me while pedaling, and because of the movements, the shirt almost always slides up over the top of the hand grip (Hello Everyone! Look at Me! I'm Flashing My Big Ol' Revolver! Please Write Me Up Officer!)
I decided to take a different approach and tie wrap the holster to my bike frame up near the neck covering over the holster and hand grip with cloth. It's quick to get to, but the down side to this is I cannot lock my bike and enter a store, lest someone gets nosey, looks under the cloth, and five finger discounts my gun.
If you do it this way, you have to be one with the bike at all times.