Sunday, February 06, 2011

Form = Fitness + Freshness: Take 2

A few weeks ago I posted about gaining some form after a race win in a local crit.

Here's take 2.

Yesterday (Saturday) and Friday I raced the Aussie national track cycling championships in the para cycling categories at the Dunc Gray Velodrome here in a blazing hot Sydney. There are only two events for individual para cyclists - the time trial and the individual pursuit. So I enter both. For my para category (C4) that means a 1-km time trial and a 4km individual pursuit. Ouch.

The day before that I had to go through reclassification. I was first classified in 2009. I suppose there was a slim chance my leg might have grown back since then.

Not having raced the "kilo" before, I just went at it hard but keeping a fraction in reserve on the opening lap. The kilo is raced as an individual, whereas in the pursuit you are racing on track at same time as your opponent (starting on opposite sides of track).

I finished the kilo in a 1:16. My opponent rode a 1:15. I was 1 second in front after 750m but my fade in the final lap saw my opponent overhaul my time. Happy with that. Much room for improvement from me, so something to think about for next year. A little more than a couple of week's notice of getting a ride might help...

The next day we had the individual pursuit. Here's my power trace:

Just power and cadence showing.

Average Power: 363W
Time: 5:08
Place: 2nd

Again I was pretty happy with that. My 5-min power/weight ratio was an all time personal best pre- and post-amputation, and the time was 4-seconds faster than previous national record. My opponent though had a fantastic race, going 4:58 and setting a huge new PB for him. Nice work Ryan! :)

CTL: 96
TSB: +8

Once again, Form = Fitness + Freshness

Next up - Team Pursuit later this month.


Lawrence said...

Awesome stuff dude. I'm so stoked for you! Keep rocking on!! :-D

Olivier ROMEYER said...

Hello Alex,

First, sorry about my english if there is some mistake ...

I'm looking about the shape of the cadence and i don't understand the reason of the oscillation ?
Is it normal and specific on a track (slow cadence in the curve) ?

Olivier (addict of your blog)

Alex Simmons said...

Hi Oliver

No problem with your English!

The oscillating speed and cadence trace is normal when riding the track.

The power meter measures wheel speed and cadence (which of course are directly linked to each other since it's a fixed gear bike).

The apparent oscillation is due to the variance in measured wheel speed as you move from riding the straights to the bends and back again. Two things are going on:

1. In the straights, the wheels are in line with your centre of mass, so both are moving at the same speed. In the turns however, the wheels trace a wider radius than the centre of mass, and so there is an apparent increase in speed as measured at the wheel compared to the speed of the centre of mass (which is what is conserved).

2. A second order factor is that when you transition from the straights into the bends, you begin to lean over, lowering your overall centre of mass when in the turns. That reduction in potential energy (i.e. height) is converted to an equivalent increase in kinetic energy (i.e.speed).

Of course, as you exit the bend and return to the straight, then the opposite occurs and wheel speed/cadence reduces.

Hence as you go round the track, the speed as measured by the wheel moves up and down, even though you are keeping everything as smooth as possible.

Experienced track riders get used to the variance in cadence and learn to not let it "get away from them" as they make the transitions.