It could perfectly be a seize. Just don't know yet. Lots of things to try today.  Just thinking when it quit it throws the weight to the front so there was not much weight on the rear wheel. 

I vary the speed when I ride, esp. yesterday.  Had it up to 70 or so and then back down to the 40-50 range.  Don't or did not have it a constant speed for more than 30 seconds on my 5-6 mile  ride. 

Thanks for that info on the coil.