After writing the previous post, I wound up taking a ride down the same road as yesterday's "incident". I toted a can of pepper spray, and sure enough at the appointed house the yellow lab came bellowing out at me. I shot him with the spray, but didn't make a really solid hit. He backed off instinctively, then came again. I sprayed again. Again he dodged it. We repeated this about 4 or 5 times, and then he ran out of steam and let me go.
His buddy, the black dog (possibly an Australian shepherd) that had gone after my wife, was up next. I squirted him a good one, but didn't see if I made a good hit or not.
I continued my ride, which was an out-and-back style ride, and knew I'd be passing those same dogs on the way back. Right on cue, the yellow lab came charging out at me. This time he held a good line relative to me, and I let him have it full in the face. I could actually see the stuff dripping off his muzzle. He backed off, but the sting hadn't set in yet, so he came again and I shot him again, thinking to myself "BOOM! Headshot!"
He finally clued into something going wrong with his face and peeled off to shake and rub himself on the grass. His little black buddy arrived, but wouldn't come within 10 feet of the road, so I took it as a sign that I'd gotten him pretty good on the first pass.
This is going to be my exercise route for the near future, until that little bastard finally learns his place. After that I've got a mental list of dogs needing education, and I'm going to diligently apply the lesson until they're all better canine citizens.