Time trial performance

I’ve had it! No more aero bars for me. And this time I’ll stick with this decision.

Why the outburst? Last year in Manchester I rode my 750m TT on sprint bars. And I just sucked. My time was .5 seconds slower than a year before.  After a quick analysis of the data (the 2013 and 2014 lines in below graph) I managed to convince myself I’d do better
with aero bars. Everyone else rely on them relies on them so why not I.

TT performanceThis year I did ok. Not as well as I wanted to, but ok. In addition it felt like I had a decent start so I was anxious to see my splits. Unfortunatly it seems to take forever for the official results books to appear online. A friend of mine had taken a video of my ride so good, I was able to hand time my sections. The data I got out of it speaks volumes.

The above graph illustrates the average speeds for different 125m sections of the 750m TT.  The green colour line represents this year’s race. As you see my top speed has improved quite a bit, which quite frankly is not a huge surprise considering where the focus of my training has been: 60% of my training volume has been in short sprints. Back in 2013 I spent a lot of time doing 45-60 second efforts to develop my anaerobic capacity. That is the story behind the red tail not declining quite as much as the other two. Comparing the red line to the blue led me to believe I’d be better off with aero bars. Seemed like I was able to hold the speed better when on skies. That was a good theory. Unfortunately 2015 data does not seem to agree with it. Now my current theory is I was better holding the speed towards the end because back then my anaerobic capacity was relatively better than my anaerobic power, not because of the equipment.

TT powerBefore I had the 2015 splits I put together a graph of power duration curves comparing the 2014 ride against this year’s data. There’s one thing to understand when reading this chart: This year I missed a good 4 seconds from the start, due to the recording delay of the SRM. Because of that I’m lacking few data points that would most probably lift the tail of the green line just a bit. If you compare the info from this to the info from the split chart you can clearly see the what an impact of my focus on short sprints have had on the entire speed graph.

Comparing my performance with the competition it is clear that aero bars are not the solution to my biggest problem in the 750m time trial. A 21 second opening lap is not going to cut it, especially when my competition is at 19 seconds. Why the hell I am so slow then? Poor start technique is surely one reason. Another is the gear. Time trial setupEach year I have added one teeth to the chain ring. The third, and final, takes me back to handlebars. My arms are really long. Therefore it is really hard to create a setup in which the base bar is low enough to ensure my torso, which is not that small either, does not act as a sail when trying to collect speed.

So back to sprint bars it is. This time for good! If nothing else, at least I feel at home with them. Something I cannot say about the aero bars.



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s