Question about power, hills and IMWI

Switching to a compact crankset is usually a good thing for age groupers, but you should probably give some more time to get used to your power meter before making decisions.  How long have you had it, and when did you do your FTP test?  Have you done more than one?  Most people tend to undershoot on the first test a little bit.

Also, have you ridden the entire IMWI course?  How did you feel?  Did you do a short run afterward?

You do want to keep the surges down. The bike shop may not realize what type of race it is. What is your cadence doing during the higher power outputs? Compared to more normal for you? You may just need to calm down on the hills as many often put artificial restrictions on themselves at times.

Ok, if you're at 89 for the course and dropping down regularly for the hills then you're probably a bit higher in the flats too. Dropping in the 60's is kind of low for you, so good idea in checking out what you can do. Some people do actually forget to put the bike in the lowest gear. And also trap themselves into thinking they can't go any slower and force themselves to work harder with some false logic. I was wondering how much slower you would actually go if you did keep power down as it may not be as much of a drop as some think. However, you are already in the 60's. As another poster suggested, double check the chain ring sizes. I have heard of a 38, but it's not really common. A 52/38 could be either compact or standard crank, so need to see about that too. If it's already a compact you could swap the rings out. If standard then a compact crank would be in order as the 38 is the smallest a standard can go.

Said I believed you before about being in the lowest gear, just explaining why I asked earlier. Also that 60-70 was low enough that your inquiry towards lower gearing is warranted. 

If you're really going to "tip over" at 60-70 then I would suggest emphasizing handling some more. It you said values less than half that, then it would be more likely. What's more likely is that you're losing a bit of control by pushing that hard. Fine motor skills while also beating yourself up take some practice to do. Try it in an area where you don't feel like you have to push so much to keep going. Looking like you're still going 6.5-7 mph with the info given.

Good to see the numbers are correct, though still kind of stuck on which option would be for you. "Semi-compact" is a made up term for people who didn't understand what it was for in the first place. Standard and Compact were for the the spacing of the 5 bolts that the chainrings attach to, not the chainrings themselves. Their sizes are 110 and 130mm. A 52/38 could be either so can't tell if you only need to get new a couple new chainrings or completely switch out the crankset. Although the second isn't necessarily that bad when considering you can resell the original for something.