The speed you can achieve
on your bike is determined by two factors:
1. How much power you can
produce
2. Wind resistance.
The faster you go, the more wind drag you need to overcome.
A
few months ago there was an excellent article in Velonews (Vol 39, No 3)
about which aerodynamic equipment benefits most during an individual time
trial. What they didn't do is rank the cost vs. benefit for each piece
of equipment and the associated time savings. Years ago I saw something
like this done by cyclingnews and found it extremely interesting. Unfortunately
it's buried deep in the internet and is lost forever so I thought I'd rehash
it for those of you who missed it.
The following chart shows
the aerodynamic savings according to what www.aerosportsresearch.com
calculated for Velonews
(I bascially copied the photo above and the chart chart below and added in
the approximate costs for each equipment piece).
A couple notes:
- These numbers are
calculated for a rider over 40kms at a time of 48minutes. Faster than
most of us could go!
- I don't understand
the rational of some of their wheel comparisons and why they didn't calculate
the difference between a standard rear wheel and a rear disc wheel. I
tried calculating the numbers myself but couldn't get them consistent with
the numbers in the chart. In any case, this illustrates the point of
the cost-benefit analysis.
Biggest Bang For Your Buck?
1. Using aerobars
that allow you to get into a tuck position will be the cheapest thing you can
do for the aerodynamic benefit. You can get a set of aerobars for $200
and they'll save you a couple minutes in a 40km TT.
2. Getting a skinsuit
will provide massive benefits. The only disclaimer here is that
the testing shown here was done on a specially designed skinsuit for Nike,
not a standard skinsuit. I'm sure this skinsuit costs in excess of
$1000, but you'll realize large gains with a standard skinsuit as well.
The chart above shows an extreme comparison between this Nike skinsuit and
regular jersey/knicks in windtunnel testing.
3. Shoe Covers
will cost you no more than $50 and could save you half a minute in
40kms. Shoe covers smooth turbulent air over the straps and buckles of
the shoes.
4. Upgrading from a
regular helmet to an aero helmet could
save you over a minute for a $200 spend.
5. Time Trial Wheels
are getting into the expensive end of TT equipment spectrum, but they do
provide some good time savings and look very PRO. Having an aero front
wheel will make the most significant difference and will cost the least of
the two. Most of you probably already have a set of deep dish aero
wheels for racing anyway. A rear disc wheel is one of the last items
you should spend lots of money on if you're looking for big savings.
However, if you want to look cool this should be the first item on your
list ;-) A good analysis of different wheel types vs drag in
different wind conditions can be found on the HED
website.
