No AGs really could have changed their tactics. We were all surprised on the way home that there wasn't a head wind. There's too much going on in the morning for someone to be really digging in on the weatehr forecast, and in the 24hours before it was changing all the time. I still went SUPER conservative for about the first 90 minutes and did my highest power the last 40k. IF I had known, probably would've even paced the ride. More importantly though, I would've changed the way I trained and not put so much effort into getting stronger on the bike.

I only really realized what was happening when I got to Waikoloa and there was not even a puff of wind. At the AG level, I'm not sure how you would really change your tactics. Where I was in the race, the only tactic was sitting up and letting the peletons go by rather than do stupid surges, which I had done in the past, and I rode perfectly flat NP to and from Hawi. If anything, the lower temps and less wind probably hurt me because I didn't focus on salt intake like I normally would and got pretty low on the run.

The run felt significantly hotter than the last time I raced there and I thought the new course was a lot more difficult. I didn't have a particularly good run even with being in really good run shape and coming from a hot, humid summer of training.

I think the unpredictability of the weather/winds in Hawaii make it challenging to devise or change a race strategy with the weather. It was clearly cooler in the morning with overcast skies and seemingly light winds... but it wasn't obvious that we would have zero headwind/slight tailwind most of the way home.

I always use the flags at Waikoloa to gauge how the return trip might go... but half the time, they can be fairly still when you pass on the way out and ripping by the time you return.

You could tell in 2018 that the winds were light when we passed Waikoloa on the way out, but I only smiled to myself when they the flags were also still when I returned, knowing it would make for a quicker than usual return trip.

I think when you race in Kona, you already know your target power and that's what it is, whether there is high wind or low wind.

Its not like any of us have a clue what the weather is going to be on the bike, especially on the way home because wind can be so localized based on how quickly the lava fields heat up relative to the ocean (ocean temp is stable, lava has a quick or slow ramp gradient on any day). Let's say you leave your hotel at 5 am. and you finish the bike at 1 pm, that's an 8 hour crystal ball that you need to have some magic prediction formula for, which you can't.

Like any Ironman, the weather will be what it will be. If it is super windy, you just accumulate more TSS by the end of the bike, but it's not something you can predict for a priori, so you just have to go with a target power number for the rough duration you will be riding (4:10 rider can go at a much higher percent of their FTP than a 6:10 rider)....but everyone at the Kona level roughly knows their bike split within +/- 5 min, so the power target is not this massive guestimate....so nothing really changes on course, because you already know what you need to do to execute and it's largely independent of the wind.

I don’t know about that. The day before the race, Windy com and accuweather predicted 4-6mph winds at the time that a big bulk of the field would be on the return. Extraordinary information, and a big factor to influence execution. by comparison, it had the effect of telling the field who are about to race the old IMC “ummm ... we took out the Richter climb and replaced it with a flat loop” at the race briefing.

For people trying to make things happen on the day, the news that they’re probably going to be spending 15 fewer minutes on the bike than expected is definitely something a lot of savvy folks would be paying attention to ... maybe be riding the outbound a bit more conservatively (because they’re no longer trying to push out to Hawi to beat the wind flipping), or choosing to be at the upper range of their execution power (say, riding 215NP over 205), acknowledging that they can spend a few more watts, cuz they would probably be spending 5:00 instead of 5:15 on the bike.

I agree that there’s a lot unpredictable over the day, but this wind thing was a pretty big factor that went from a known “course characteristic” the day before, to being taken off the table.

i've never been to kona let alone raced there but i'm all too familiar with riding in wind.
i'd say there are some genuine changes but largely agree with Dev, however the biggest thing is mental - not having to mentally battle the wind would make a big difference for many people, though exactly what the impact of that is would differ between people.

in the pro race of course the conditions played right into Lange's tactics and destroyed Wurf's. i suspect neither of them would have done anything particularly different in other conditions though - they both played the hands they held and the river determined how the result played out.

Some AGers probably had plans to shred the pelotons in the wind but realised that wasn't going to be easy without wind and just sat in

There is no way you show up in Kona and look at the forecast and go. "OK I will ride X watts higher because there will be no wind so I will get to T2 earlier with my planned Kilojoule consumption and start the run with the same kilojoule total expenditure, just off higher watts for less time". No one with half a brain in Kona does that, because the last time they had conditons like this 2018 was 1989. So you just ride your target "hoping" the forecast is indeed true but brace for the winds.

The problem is that the weather forecast can never predict that well what the localized heat gradients will be that create those winds down the lava undulations that he road to Hawi jumps over and under. When the road is exposed, you get hit, if the wind is flowing and then it is under, there is momentary shelter. A big cloud cover helps the keep the lava cool and reduces local effects, but general larger winds can shift.

At the end of the day, Hawaii is a black rock in the middle of a blue Ocean in a subtropical region. Its almost never that all 112 miles over 4:10 to 8:30 hours will have no wind. So most racers (for their own good) won't change their plan thinking its a one year in 30 event and will just respect the course expecting the full TSS load of a normal wind day...there is always 26.2 miles of running to make up the "mistake" of under cooking the bike. I think the sane age group Kona qualifier will look at it more as an opportunity to have a faster run off fresher legs if there is the up side of no wind. It's just too much of a bad gamble early in the day to roll the dice on a no wind Kona weather forecast. It's "almost" but not quite as extreme as hoping that they build a flat tunnel through Richter pass while someone is swimming the old IMC course! Not totally the same, but "almost".

So I take it you were there? You raced? you changed your tactics accordingly?

There's so much other shit to deal with in the 24 hours before the race... Plus, if you asked anyone there the night before, the prevailing thought was that it would rain all day. Obvs it didn't, and anyway who expected it to and rode higher watts would've been screwed.

Without fail, the savy guys who do the best are the ones who shut all of that talk out and focus on their own race the same way they focused on their own training and no one else's leading up.

I was and I did, and changed my strategy (but lest I be accused of backdoor bragging, I'll give some numbers to show just how puny a force I really am).

At 11 and then at 3 the day before the race I checked Accu and Windy and saw the forecast. I knew I had really diminished run speed coming into the day, so based on that information, I made a choice on my bike execution to pull back as much as possible to ensure that I was the freshest I had ever been for a run. I guess this was the type of bigger-picture strategy choice I am getting at.

Pre-wind check (following data points from prev races on the course, plus 5 full rehearsals on course plus a lot of rides on King K), I had planned the first 30 mins as 186-190w, remainder 196-200, Hawi climb 215. This has consistently been a 5:15-5:20. But I know it would mean coming into the run pretty depleted, and would erode already slow run speed.

After seeing the forecast, and making a decision to do whatever could to preserve my run legs, I decided to race at 170-175 (with a HR cap, to boot), BUT to do it in as aero a position as absolutely possible (which is a much, much more aero position that I could hold if I rode the 196-200 plan above, and not one I could hold on a typical Kona windy day). And maybe it's not one of those trophy positions that are the things of ST beauty, but a low head, rounded shoulders, and punching as small a hole as I could.

anyhow ... in the end, I think* my NP ended up around 164, and I was 5:00:0-something off the bike. Bigger accomplishment was the best possible run I was capable of given my fitness on that day (instead of a run that was already chewed up by the bike).

I believe if I stayed to the original plan, it would have been a slower overall result - possibly the same bike time, but definitely a compromised run split.

*hazy; might have been lower

also, just looking again at the responses, I should probably clarify that my use of "tactics" is meant to mean "tactics of immediate decisions as they pertain to racer vs the course," instead of "tactics you would employer as racer vs other racer." Sorry for the clumsy terminology. I agree with you entirely on focusing on your own day, and tbh, I wouldn't know the difference between another dude in my AG, and a shit-lined shoe when it came where my attention is on a race day.