Friday, August 25, 2017

LEOMO TYPE-R and the PCD - Power,Cadence,Dead Spot Score

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.


  1. Absolutely love the geekiness of all this technology, but are you sure it isn't 42?

    1. It might be 42. But, that’s only a theory I came up with after a Pan-Galactic gargle blaster. ;-)