How not to ride a century (power numbers)

I was thinking the same thing.  19 beats seams like a wide range for Z3.  But, HR is a personal thing. :P

I just got my PM too, so I will see what my 5 hr ride power looks like on Saturday.  I am sure you noticed this too, but your cadence dropped in a huge manner from miles 67 on.  Your HR did too, so perhaps Nutrition issues, not just your pacing?

On the HR zones, my coach uses a little different setup than the Friel zones.  From what I can tell (and I really don't over analyze these things - I just to just shutup and do what coach says) is that his zone 3 is a Friel zone 2/zone 3 overlap.  My zones are on my workout log along with my LT numbers and you COULD take the time if you wanted to compare them to what Friel and others would calculate. 

On the nutrition thing, it COULD be; I am still new to this game and trying to figure it out.  I definitly have had too much sodium and calories in the past and I think I've got that dialed in better now. I think the main issue above is going out too hard in the first 33 miles.  A long ride like this normally would have been more more zone 2 (which for me would be 125-151 (I know, not Friels, but it works from my coach)); so going for this long at zone 3 was something new.

 I have another century weekend after next to test more things out.  I had picked (rather arbitraily) to try for 150-200 watts and to see what I could hold for last weekends century.  Aside from having my power zones setup, I'm definitly going to start lower and strive to hold that for the entire ride rather than drop off (maybe 130 to 180 watts). 

Based upon the data from your ride last week, I'd guess 140-160 would be a good place to start.  130 seems low given you finished near there while clearly fatigued and 180 is more than you averaged while 'fresh' and before you 'crashed'.