Training and racing with power

Powermeters are not a new concept in cycling, and the British Cycling team were early adopters of the technology at the end of the 1990s. However, the affordability of the systems and cheap software to take advantage of the results has been some time coming. They have been more prevalent in the UK time trialling scene in the last three or four years, and I was getting more and more curious about this new technology. I wanted to be able to quantify more precisely the sort of training and racing I was doing (my HRM curves, although useful for giving me the overall picture, weren’t really giving me much more detail than my own perception of my effort was – I am hoping to be able to determine how good a ride I’ve actually done on a particular day), and also to use power to pace my long-distance efforts more evenly, as well as use it as an aid to improve aerodynamics (if you know how much power is going in and how much speed is coming out, you can interpret how much drag you’re generating).

A day after the Ben Owen 10 I took delivery of a Power2Max powermeter. Well, two actually – a 130bcd (bolt circle diameter) for racing and a 110bcd for training, both ready to fit to the Shimano Hollowtech II bottom brackets I use. They were relatively painless to set up and each one only took about half an hour to bolt together, fit chainrings and test with a quick circuit up and down the road. The 110bcd will live on my summer bike or my winter audax bike, and the 130bcd will be used on my TT bike or the fixed gear bike I’ve started using this season for club TTs. (I’d seen from other people’s testing  that using a P2M as a fixed gear powermeter was OK – the new version seems quite tolerant of changing ring sizes and useage.) Here’s the racing model fitted to my TT bike (I had to cut a notch out of that aero chainring to get it to fit over the battery compartment – the notch is neatly hidden behind the crank arm though).

My first few race rides were done without reference to power output – I just watched speed and time on my Garmin as I usually do. The first few weeks are all about gathering a bit of data to establish a baseline. I had a poor ride on a windy day at the Newbury RC 10 on the Southmoor bypass [Result], and then a much better one at the a3crg Monday evening 25 [Result].  Pic from the Newbury RC 10 by Biker Jun:

The a3crg event was relatively windless, meaning it was possible to extract some drag data from it. It turned out I’m pretty slippery through the air already, but not especially powerful (as you might expect from my easy start to the year), and rather poorer at pace judgement than I thought!

Since then I’ve ridden a few more evening 10s on fixed – looking for better pace judgement – and taken advantage of a few still early mornings before work to do some aero testing. I’ve also used the powermeter to see what shape my “power profile” is and how my power changes off on long training rides of 4 hours or more. There’s loads more to come, and I’ve only really just started to get to grips with the data. It certainly takes a lot of the guesswork out of racing, as I’ve found with the last couple of events I’ve ridden.