TIME TRIALS
(recalculate your time to compensate for wind)
The ideal time trial course would be flat and with no wind.
Ideally, one would ride equally hard in both directions and the time going
out would be the same as the time coming back (I'm talking here of an out and back
course). Alas, that rarely happens in real life.
The reason for time trials is not just to judge oneself against others, but
also to monitor progress made through the biking season. One should be able
to see the speed go up over time. Most of my time trials are done alone,
there is no one a minute ahead of me to try to catch or a minute behind to
stay in front of. It's just a personal test and form of exercise that is
more enjoyable than riding a trainer indoors, and I almost always workout a lot
harder in a time trial than on my trainer.
One of the
problems I have, though, is judging my progress from day to day or week to week.
One day the wind is calm, the next the wind beats the crap out of me.
Did I improve? It's hard to say, I could have ridden better but still
had a slower speed because of the wind.
Fortunately,
I've found a way to compensate somewhat for the wind based on the assumption that
if the wind slows me down one way it might help me go faster by an equal amount
in the other directions. It's not perfect, but I feel it helps even out
my times due to wind (or changes in elevation). I keep track of my time
at the turn around point as well as the finish line to the course. From
these I can calculate my average speed going out and my average speed coming back
and then average the two speeds. I use the average of the two speeds to calculate
an adjusted time for the whole course. (This is not the same as getting
an average speed for the whole course.)
For example, let's
say I rode a 10 mile course in 30 minutes and it was a windy day so that on
the way out it took me 18 minutes but I streaked back in 12 minutes because
of a tailwind. My average speed for the whole course would be 20 mph.
but my speed on the way out would be 16.66 mph and my speed back would
be 25 mph. The average the two speeds is 20.833 mph, more than half a mph
faster than my speed for the whole trip. Averaging the two speeds always
gives a faster speed than the average speed for the whole course (except when
the two speeds are equal - the perfect time trial). Using 20.833 mph to calculate
a new time I get 28.8 minutes or 28:48. So if the day had been less
windy, I might have ridden the course a minute and 12 seconds faster!
It's not perfect, but it's been my experience that it
helps level out variations in time from day to day. If I have a strong crosswind,
which slows me in both directions, it's not going to compensate at all
- it works best with a headwind-tailwind combination. Also it works best
in an out and back course (as opposed to a rectangular course). It doesn't
compensate for getting tired and dying in that last mile. The correlation
is not exact, and there are other variables I'm sure, but it does help me to make more
sense of my times.


