I’ve entered my first ever TT (as a bit of a laugh if I’m honest) but a few mates heard about it and have also entered and suddenly its got a bit serious (bragging rights etc, etc.
I can’t let any of these people beat me.) It’s a 25miler on a flat course. I only have my usual road bike but someone has offered me clip-on bars. My question is, do I use them? And, short of buying a new bike, is there any other way I can change my position to go faster?
I’m used to riding for hours in a sportive so the distance shouldn’t be a problem but how do you pace yourself for these shorter events.
Simon, the clip on bars will create a more aerodynamic position but you need to be sure that they don’t compromise your performance by forcing you into such an unfamiliar position that you lose too much power.
You can lose a little power but still go faster provided the loss is offset by greater gains from being in the more aerodynamic position, which on a flat course will be significant providing you can maintain it for long enough. So you need to train yourself to be able to do that.
Aerodynamics is a key area for cycling generally and time trialing specifically, so improving your position and set up, is important and can be achieved by addressing the three main factors that contribute to aerodynamic drag. These are;
Cross-sectional frontal area: Quite simply how much of a target you and your bike is presented to the onrushing air. Using clip-ons and practicing a lower and narrower position will create a smaller ‘target’.
Drag coefficient: How the air flows around your bike and body. Many things affect this but generally it’s all about achieving the fewest number of nooks and crannies which air can get into by creating as many smooth surfaces and sleek lines as possible.
So think about getting your arms in front of your knees and having the least number of bits sticking out from you or your bike as possible, and yes that includes loose fitting kit like flappy jerseys etc. Now you know why TT riders use pointy helmets, skin suits and disc wheels.
Relative velocity: This concerns your question about pacing. If you could maintain a speed of 40kmph on a perfectly still day, with no wind, that would mean the same relative velocity as riding at 20kmph into a 20kmph headwind or 50kmph with a 10kmph tailwind.
So clearly road speed is not a very good indicator of performance as you won’t be able to judge wind conditions accurately (and they’re not constant anyway). So a better way to pace yourself is to have a good idea of your ‘critical’ pace – the kind of effort you can maintain for the time it takes you to ride the event distance of 25miles.
You can do this by practicing the course and measuring your effort with a heart rate monitor or better still a power metre if you have one available.
Huw Williams, BC Level Three Coach