Tuesday, February 18, 2020

Monstercross Revisited: a bit more analysis

With a couple of days between me and the race, I figured it was time to shift from focusing on what went wrong to what went right. And there was plenty to be happy about.

First off: no mechanicals. I often take that for granted, because I try to take good care of my stuff, but there were riders all over the course working on their bikes. In 2016 I flatted and crashed twice, and I've torn up a fair bit of equipment in Poco on other occasions.

The jockey wheels started sounding awful at 15 miles, and the bottom bracket is probably toast, but everything made it through. Honestly the biggest issue I had was a couple of slow shifts near the granny end of the cassette, which is to be expected for a cable set that was installed almost 3 years ago and has almost 1000 off-road miles. (NOTE TO SELF: replace the cables)

And with new wheels and tires that had literally only seen service riding up and down my driveway one time, I wasn't sure what I'd be in for over 50 miles. I'd previously mounted the new tires on my old wheels and struggled to keep the front sealed, but last night, 30 hours after finishing the race, they were only 4 psi down from my pre-race inflation. Woohoo!

Second: no crashes. I missed the same turn on both laps but was able to ride the outside berm. I took careful lines through the water crossings and knew the course well enough to avoid some of the worst tire-damaging obstacles. The bike got loose a couple of times, but I always gave myself room to work.

Third: my body performed exactly as well as it could have, given my limited training time. I don't run a power meter on that bike, and yes I know Strava's estimated power is about as accurate as writing down random numbers in the dark, but what it reflects is exactly how I felt, and exactly what I expected.

Hour 1: pursuit (~204W est., HR 170 avg.)
Hour 2: maintain (~188W est., HR 170 avg.)
Hour 3: wane (~162W est., HR 163 avg.)
Hour 4: fail (~106W est., HR 151 avg.)

Obviously hours 3 & 4 would have benefited from actually eating, but the overall average estimated power is exactly in line with what I've done in previous 3+ hour events, even when on form, so I'm frustrated, but not disappointed. I know I need to add longer training rides to my regular schedule.

Fourth: I got my layering exactly right. I mean *exactly*. The temps were supposed to go from 40F at the start to 55F by the end. If that had happened, I'd have been over-dressed. But it didn't:


I never regretted the leg warmers, the wool socks, or even the long-sleeve baselayer. The light hat, mid-weight gloves, and summer shoes were also, weirdly, exactly the right calls. Usually my extremities suffer in these conditions, but even after jamming my right foot straight into the freezing creek, I was fine.

Fifth: if I can fix my nutrition game (which should be a simple as not wearing a pocket-less skinsuit), I'll be in contention for a decent finish. I ended up 25th of 86 in the men's open, but would have been closer to 18th, had I not completely collapsed in the final miles. A time-gap conveniently shows exactly how much ground I lost to one of my closest and most equal competitors:


As mentioned in my previous post, I made the split when the rider behind me crashed in the creek, and put just about 4 minutes on him over most of the 2nd lap. But right there at mile 42 the tables turned. Even though I gave up 3 of those minutes in my slow-roll toward the final trail, I still could have held him at bay through the final mile if I had just been able to ride the bike. He finished 19th.


But though I am frustrated with my finish and my nutrition strategy, I can be proud of having put down one of my hardest efforts ever. In fact, 3rd hardest according to the graph, as measured by Strava's "Relative Effort" metric. Only my first century and the 2016 Richmond marathon were "harder".

Now, Relative Effort isn't exactly science. It's just a measure of heart-rate deviation from max over the time of the event, so it doesn't take actual power into account. So while my relative effort was high, it doesn't mean my power was, necessarily. The estimators show I haven't lost much ground in the power department, but I do know I have some work ahead to be in peak form for the road & gravel season. That said, 2.5 hours at Z4+ is nothing to sneeze at.


What it means for me, though, is that I'm on the wrong side of what I call the "wattage economy", or power / heart-rate


You can see in this chart that that has generally trended upward at this time each year, but there's a catch. This year, as with every previous year, I've been doing most of my winter training on Zwift. Racing, group riding, whatever. But this is the first year I've relied entirely on the bike's power meter to measure power. For a while I didn't even bother with spin-downs with the Kickr Snap because they would just fail. A few months ago I started to realize that the power reported by the Kickr didn't even come close to matching the power meter on the bike, so I standardized. My TT bike has its own power meter, too, so I'm consistent across the board with measuring at the crank/spider. So while the numbers are down comparatively, I think it's probably misleading: Zwift was recording numbers that were high by as much as 25%, in some cases (sorry Zwift community!). And either way, it's trending upward from January (1.28) to February (1.34).

Better still, my power is closing in on my best ever Wintergreen hill-climb average, and that's only 2 months away.

So there's a lot to be happy about. I have to do some work before the bike will be race-ready again, and I need to add some longer rides to my training calendar, but all-in-all things are looking pretty good!

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