The PCD (Power, Cadence and Dead Spot Score) Map is an
excellent tool to review on a regular (daily) basis. The PCD map consists of Cadence on Y axis, Power/Wattage on X axis)
the frequency of your “dead spots”. As
the percentage of dead spots within a particular Power and
Cadence range the increases, the box will change color from Green to Red. The opacity of the box has to do with count
of the total “cycles” within that power/cadence combination. If you mouse over the box, you will see the
Dead Spots in relation to total cylces or revolutions. This map was developed by myself, along with
Dr. Michael Coco and the team at LEOMO in order to solve the seemingly
“unanswerable/ultimate” question: What
is your optimal Cadence and Power combination? It turns out that using the TYPE-R motion analysis device, your power meter, and the PCD
map, you can darn near if not outright answer the question. (And the answer isn’t “42” for all you
“Hitchhikers Guide to the Galaxy” fans).
After having studied many of these maps now, I have found
that each of us have multiple “optimal” cadences. What the real question we should be asking
is: What is our optimal “gearing” for a specific cadence and power combination?
This is what the PCD map is showing
you. Where is the pattern on the map
that gives you the least amount of dead spots?
These are your optimal gearing combinations.
Let’s take a look at what I would consider one of the best
PCD maps I have seen. This rider is PCG coach Gary Hoffman and he has been
racing bicycles for over 45 years now, had tremendous success at local,
regional and national levels on the road and the track. Gary is the epitome of efficient and
economical. He wastes no energy ever on
the bike and when you see him ride, it appears even more effortless than the
best TDF pros. He’s clearly honed his
pedaling technique with millions upon millions of revolutions. Notice how his
“pattern” that I have so precisely(sarcasm) drawn over his map. This pattern is a diagonal from bottom left
all the way across his entire power band to the upper right at the highest
cadence values. This shows his Optimal
cadence for each power output across the entire map. Not many people have this ability across all
wattages and cadence ranges.
Not only does he have great range, but both legs are
basically identical! This is what you are looking for: A pattern in your map
where there are less deadspots.
Let’s contrast this with another PCD map. This map was created by an athlete that has
been riding for 20 years, went on a long ride in the middle of summer with 95
degree heat, got dehydrated and over-heated.
First, have a look at the first half of his 5 hour ride. Clearly over 90rpm, he produces less dead
spots, but as soon as he drops below 90rpm, his frequency of dead spots
increase.
Now, have a look at the second half of the ride. This shows just how much fatigue can
contribute to poor motion patterns, which in turn contribute to more fatigue
and a downward self-replicating spiral.
The second half PCD map displays a lot more red especially
with the right leg and across all wattage and cadence ranges. His left leg seems to be pretty decent still
above 90rpm, but even at lower wattages (under 150w) he has more dead spots
with the right leg in the second half of the ride versus the first half of the
ride. Clearly an example of fatigue.
Let’s take a look at another rider in a recent training
ride. This was a tempo ride that had two intervals of 20 minutes each at his
“Sweetspot” (88-93% of FTP).
Here we see that above 100rpm, the frequency of his dead spots
are significantly reduced and in some cases, half of what they are at
91-100rpm. The right leg clearly likes a
little faster cadence and the left is fine at 91-110rpm. What is obvious from this map, is that below
100rpm, the number of dead spots dramatically increase and become very
noticeable between 71-90rpm.
From these three different riders, we see different patterns
of the “Optimal” power and cadence relationship. There really isn’t a “Norm” for all riders,
and has been the case with over 50 riders that I have analyzed now and each of
our optimal combinations are a little different. However, once you discover your pattern, it
will be pretty much the same unless you make a change to your “pedaling print”
in some way. The next step is to
determine your optimal for different types of riding: Hills, flats, races, etc.
