I rode 0.63 yesterday, yet it felt much harder than that and my run only just scraped under 4h 
I wonder if my PM calibrated properly. I made sure I got my AvHR down over the course just in case.
Was your FTP correct?
That’s just a slightly more severe case of what I experienced in Copenhagen. I aimed to ride about 0.73, yet that felt way too hard and I ditched the goal and rode 0.67. I did run ok though.
I don’t really find it after a 1.9k swim, and 0.8+ watts feels easy initially (I often have to hold myself back), but I do wonder if 3.8k is significantly different as it really shocked me how comfortably fewer watts still felt more of an effort that I was expecting.
Been having a look at the numbers from my ride at IMCH. Looking at the summary, I seem to have got it bang on.
All in the safe, grey zone.
My actual power trace seems to be telling a bit of a different story.
A definite downward trend after the last climb at around 4:30. I do remember trying to soft pedal as much as possible after this and consciously didn’t push on towards T2. Still might not have quite got my ftp spot on. Something to get right next year.
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VI of 1.16 would suggest it being too surgy but I don’t know the course.
That would have probably been on lap 1, trying to get past the groups which had formed and soft pedalling when being overtaken.
Yeah, the VI would be the only thing that jumps out. For just over 1000m elevation, that seems very high. I just looked at the elevation profile, and it looks to be one you could moderate power quite consistently on.
Our numbers are in general very similar … here’s mine from Copenhagen last year:
You can’t tell too much from the graphs, other than maybe I don’t have quite the same downward drift second half (although it’s there to a small extent), but the thing that is noticeable is the range of power values throughout, and the scale. Mine doesn’t go much above 200w, whereas you’ve got loads of instances of power well into the high 200s and some in excess of 300. There also seem to be quite prolonged periods of coasting (EDIT - I’ve seen your point about about having to fall back from the draft zone). I deliberately tried to pick roughly the same smoothing setting so they’d be comparable.
I’d say if you could have ridden more around 1.08 or below in VI terms, and still resulted in 182w NP, you’d have ridden a decent amount faster.
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I remember reading the Coggan book and it said for experienced guys you can target a IM TSS of up to 300
So I aimed for 275 or so to be safe
Yours are a lot lower which makes sense at an IF of .67
Am I losing my mind of 275-300 is too high?
See the graph above. 275 is the “good range for most AG athletes”, whereas 300 is into the “proven strong IM runners only”. So 275 is not unreasonable by any means.
I certainly erred on the safe side on the day based on how I was feeling (all training had been geared towards the 175-180w range), mainly because cycling is my weakness and I didn’t want to ruin the run on my first long distance race. I also knew, based on average speed, that I was still doing enough at the lower wattage to keep sub10 in play
Sorry - I realised I was referencing a chart that was already in this thread. Idiot !
@stenard @PCP Thanks for the analysis 
I did read your blog about your Copenhagen race but can’t remember if you had the same issues early on in the bike? You’re a much faster swimmer than me so was it less congested out of T1, which would make the issues with having to surge and slow less likely?
It certainly wasnt empty, but I tend to find I’m either going past someone or people are going way faster than me. So I can maintain my own rhythm using the 25s window (either to overtake, or to fall back).
Bahrain is probably the only race where I’ve had a real issue with chunks of riders all riding similar speeds to one another. I think that was a case of the speed of the course. At c35kph, people riding 20-50w different will have a distinct speed differential. In Bahrain, as the first half I was riding well in excess of 40kph, I’m guessing wattage differences become less apparent in resultant speed (due to the exponential relationship with drag and speed). Or maybe it was just a race where it happened lots of people were of similar cycling ability.
Finally got round to uploading my power file today and was surprised to see that even though I exceeded my target NP (207w vs 195w) my time was significantly slower than what BBS predicted 6:09 vs ~5:45. Atleast 6mins of that was me stopped putting on suncream and refilling Maurten bottle. I’ve fiddled with my BBS settings (added weight, changed rider position) and don’t seem to be able to recreate a ~6hr time. Which leaves me wondering, could my power meter be wrong? Or is it more likely my position was shit/power output was too erratic (VI of 1.14) First time riding an IM with power meter, any thoughts?
I would suspect your CdA in BBS is more likely incorrect. It could be your PM and might be worth getting it checked but unless you have spent time in a wind tunnel then any CdA in BBS is a best a guess.
Edit: also check your tyres CRR and input that as well if you haven’t already.
Was it a hilly/hard bike course and were you on a road bike? If not that seems to be a relatively slow av. speed for the power - suggesting either you’re not particularly aero or your power meter is generous.
@GRamsay Cheers for that, I’ve changed the CdA and managed to get it to within ~8minutes of my IM time - which is within the realms of accuracy that I can deal with.
@PhilleusPhogg It was the Ironman Switzerland course, so fairly hilly (about 1700m of climbing) and it was on a TT bike (Canyon Speedmax). I haven’t had a proper bike fit on this bike so my position could be a factor. I’m hoping it’s not the power meter haha.
TSS=384 and IF=0.79? Either your PM is reading high or your FTP is set low
How did you get the cda number? I’m assuming you used the race analysis tool (previously called the aero analyser)?
No.
If you’re a bloke, you should smash the bike, then hope everything else goes okay
How can over 75% of the field be wrong.
Ah just spotted that - so now I’ve used the race analysis tool and updated the race with those CdA values and it actually has my predicted time at 5:40 now 
. So I’m even further off. Starting to think the PM is off?
@r0bh FTP could be a little low, as I’ve only ever tested indoors with a 20 min test. But wouldn’t imagine it would be much more.
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