Let me say this up front: I don’t like time trials. The lone suffering, the mental gymnastics required to keep pushing constantly, the lack of strategic elements… all unattractive to me.
Which explains why I can count on one hand the number of Zwift time trials I’ve raced. And this includes team TTs, which I’ll admit are a bit more fun. But still not my cup of tea.
Yet here I was, setting up my virtual TT rig on a Saturday morning to take part in the weekly WTRL iTT. Why? Because every once in a while I get a hankering to do something different, something outside of my usual. Plus, after thinking through my post about Crit City Redefining ZwiftPower Categories, I had been wondering what sort of wattage I could hold in an all-out TT effort, where I wasn’t modulating wattage to sit in the draft.
By my calculations the race would last around 40 minutes. Not a bad length of time for a proxy FTP test. Let’s race!
TT Basics
Clearly, I’m not an experienced TT racer. I’ve already covered my lack of Zwift TT experience, and the only outdoor TT’s I’ve ridden have been few and always Merckx-style. I’m no TT specialist. That said, there are a few things I knew for sure going into this race:
- Don’t blow up early: the tendency is to start hard, which can burn you out for the rest of the race. Get up to speed quickly, but don’t fatigue yourself early.
- Equipment matters: when every second counts, you want the fastest possible setup. This is especially true with TT races, and more so on Zwift, where you don’t have to worry about whether your virtual cockpit fits or how your deep-dish wheels interact with crosswinds.
- Over-pace uphill, recover downhill: pushing hardest when you’re moving slowest (uphill) results in the fastest overall times. So push 5-10% over pace on uphills, and drop the power a bit once you’ve hit cruising speed on descents.
- Pacing is everything: this is the biggest thing to understand. Know the race route and your own power numbers, you should know what sort of pace you can hold. Stick to that pace, avoiding the temptation to go harder early or ease up when you’re suffering.
The Warmup
I began the morning with my typical race prep protocol: two pieces of caffeine gum and some PR lotion on the legs. Then it was over to Tick Tock, where I started by equipping myself with one of the fastest TT setups in Zwift: the Felt IA frame and Zipp 858/Super-9 wheels. This was a flat course, so bike choice was easy: simply use the most aero frame and wheels available.
I added an aero helmet to complete the look, then headed out for a ~20-minute warmup where I made sure my heart rate got up to 160 a few times. Always a good idea to make sure the engine is firing on all cylinders.
Variability
We were riding one lap of Watopia’s Waistband, a 25.5 km (15.8 mile) route with only 95 m (312′) of elevation. This was good news: I like flat routes for TT’s, as I can keep my effort quite steady. I do best with low-VI efforts.
(What is VI, you ask? Variability Index, according to this TrainingPeaks article, is “a way to measure how smooth or ‘variable’ your power output was during the ride. It is calculated by dividing your Normalized Power by your Average Power. A steady and even output, like during a triathlon, should have a VI of 1.05 or less. During a criterium race your VI may be as high as 1.2 or more.”)
VI for indoor riding is generally lower than outdoor, given the steady-pedaling nature of Zwift rides. This is why you’ll hear cyclists say “Zwift racing is a lot like a TT effort.” Because power is more steady in Zwift races, even road races with drafting enabled, due to how Zwift’s pack dynamics and physics work. Additionally, a lower Trainer Difficulty setting (I run mine around 30%) will logically result in a lower VI, since you have less resistance fluctuation affecting your pedal pressure.
The Start
A TT race doesn’t start like a typical Zwift road race, since you don’t have the stronger riders attacking in order to establish that initial selection. Instead, a TT race start is all about getting yourself up to speed quickly, then settling into your rhythm.
Our group immediately strung out, and I found myself in 2nd place, behind James Bailey. Right away I was second-guessing my effort level. Was I going too hard? I was holding 320-330 watts, and felt alright, but I also knew that this would be right on the limit of what I could do for 40 minutes on a good day. And I wasn’t convinced this was going to be a good day.
I averaged 320 watts over the first 10 minutes, covering 7.1 km. This would be my highest power average of the race, which means I did go a bit too hard, too early. Rookie mistake.
The Middle
I tried to hold my power steady in the 320 watt range, but I could tell I was flagging. I also did my best to up my effort on any inclines, following the TT mantra of go hardest when you’re going the slowest. But I was still losing ground, sinking to 7th place in our group of 40 by the halfway point.
I averaged 304 watts for the second 10 minute block, covering 7.1 km.
The third quarter of the ride was my worst. I was struggling to find the best cadence, swapping uncomfortably between spinning and mashing. I did find that working in a lower cadence in a tougher gear seemed to let me hold power a bit better, so that’s what I settled on. (Except when that got too hard, and I shifted to an easier gear. It wasn’t pretty.)
This was so different from the drafting-enabled road races I typically do in Zwift. Those races are all about making the front selection, attacking where it’s smart, and conserving energy for the final push. Here, though, I had to constantly remind myself to keep pushing, to go all in. Maintaining top speed was the priority, and that meant riding right at threshold almost constantly, regardless of what other riders were doing.
I was also riding in camera view 3 (first person view), which I like to do. I usually don’t use this view for normal road races, since I can’t see riders around me as well. But for a TT, why not? Let’s immerse ourselves in the painful experience!
I kept a constant eye on the rider list, looking to see who was gaining on me and if I was gaining ground on those ahead. The results weren’t promising. I was losing ground to S Pruett and M Costello, and not gaining anything on my teammate K Rohrlach up the road.
I averaged 301 watts for the third 10 minute block, covering just 6.5 km. 320, 304, 301… things were trending in the wrong direction.
The Finish
As I left the volcano circuit with approximately 10 minutes to go, I steeled myself for a final hard effort.
Only 10 more minutes, Eric. You can push harder for 10 minutes.
I’d been passed by a hard-charging A Kraemer as we left the volcano, putting me in 9th place. But I had been paying attention to the riders up the road, and was pretty convinced that three of the eight ahead were going to be disqualified in the final results. (The first place rider was on zPower, and two other riders had been holding ~4.5 w/kg pretty steady.) If I was correct, that meant my current finish position was actually 6th, not 9th.
Two riders were just seconds up the road: S Pruett and K Rohrlach. If I could finish ahead of them, that would put me in 4th. It wouldn’t be a podium, but it would be close. And that was just the motivation I needed as we turned off of Ocean Boulevard toward the bridge toward Fuego Flats.
5 minutes left. You can do anything for 5 minutes!
I stood up, hammering my way across the dirt section and up the bridge, knowing Crr differences on these surfaces would make me roll even slower, so extra power would help me put time into the competition.
Pruett was 3 seconds ahead, Rohrlach 6 seconds…
I kept the power up, holding somewhere around 330-360 watts. By the time we passed the desert start pens, Pruett and Rohrlach were just wheel lengths ahead.
Pruett was pouring on the watts, but Rohrlach appeared to be flagging. I passed them both before we exited the loop section just before the sprint start line.
Less than 1 minute! Empty the tank!
I shifted and stood up, knowing the final sprint was only a ~35 second effort. Pruett put in a good dig, but I was able to stay ahead, finishing 7th. And just as I had predicted, that meant 4th place on ZwiftPower. James Bailey, the rider who began in the lead, would finish 1st. Well done, James!
And well done Rohrlach and Pruett – thanks for pushing me! (As it turns out, they are both DIRT teammates. Pruett just wasn’t wearing team kit.) We finished 4-5-6 on ZwiftPower – not a bad result for the DIRT squad.
I averaged 310 watts for the fourth and final 10 minutes, covering 7 km.
See my activity on Strava >
See my activity on Zwift >
See race results on ZwiftPower >
Takeaways
This was definitely closer to an FTP test than a typical Zwift road race. Here’s a power zones comparison between a recent Crit City road race and this TT. (Both races were right around 41 minutes long.)
Notice how I spent much of my time in the lower-effort Tempo zone for the Crit City race? This is where I typically sit when I’m just hanging in the pack, conserving energy in the draft. In a flat TT, of course, the goal is to ride at your limit for the entire race. And I think I was pretty close to that! (My legs were sore for two days afterward.) Even though I’m not generally a big fan of the TT race, you can’t argue that it’s an incredibly challenging workout.
It would be really interesting to crunch the numbers and graph some sort of probability curve for race results based on a rider’s wattage and whether it’s a TT or standard road race. Because wattage certainly seems to correlate more closely to results in a TT compared to a road race, where strategy plays a more significant role. (See the results of this TT vs the Crit City race above as an example.) This makes the TT less interesting, in my mind. But I can see how it would appeal to a purist as well.
Lastly, I was left questioning whether I could have pushed harder, especially doing the 2nd and 3rd 10-minute blocks of this race. It was so challenging to stay focused and keep the power high during these sections, but I had good power at the very end of the race. Did that mean I had more to give in the middle?
There’s only one way to find out, and that’s to take on this awful challenge again sometime down the road. It probably won’t happen any time soon. But it will most certainly happen.
Your Comments
Are you a fan of the iTT? Got any tips for me? Share below!