Dead Spot Score Explained (part 3)

Hello, I’m Fukuma from LEOMO. In the previous two articles (part 1, part 2), I’ve introduced the details behind our MPI score DSS (Dead Spot Score) using graph data and video.

Part three will conclude the DSS introduction series by answering the question posed at the end of part 2: in the video example, are there any other points where DSS is occurring other than one we pinpointed at the 6 o’clock position?

Answer

Here is the video from the previous article, where we pinpointed the dead spots occurring at the 6 o’clock position:

There is one more prominent dead spot location other than the 6 o’clock position. Can you locate it?

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Answer:

Dead spots are also occurring right after the 12 o’clock position.

If you were able to spot that, you have excellent observation skills! If not, don’t worry since it’s almost impossible to see by eye. But it’s crystal clear in the data:

LEOMO DSS Part 3

The sawtooth shaped red line represents the pedal’s position. Each “tooth” represents one crank revolution. The top edge is the top most position of the crank, the middle is the bottom most position of the crank, and the bottom edge is also the top most position of the crank (reset point).

Looking at blue graph (rotation speed in degrees/sec (vertical axis) of the foot), you can see that not only are there big dead spots at 6 o’clock position, additional (though smaller) dead spots are occurring at the 12 o’clock position.

LEOMO DSS Part 3-3

This graph is used to create the DSS pedal stroke visualization on the LEOMO web app, and on the TYPE-R head unit in real-time. You can see the big dead spots along the 6 o’clock position and smaller dead spots along the 12 o’clock position in the graphic below, created from the same ride data as above:

LEOMO DSS Part 3-3

By the way, when this athlete increases effort using more power, his dead spots decrease like so:

LEOMO DSS Part 3-5

There are still some traces of dead spot-ish wobbles, but the values are so small (less than 0.1), DSS will show 0.

Here’s the 0 DSS pedaling video again:

Conclusion

As described above, the TYPE-R can reveal movements which are very difficult to spot by just using your eyes. We found that many people can tell “something is off” about the pedaling, but can’t pinpoint what is making them think that (there are usually many components observed subconsciously). By recording movement using the TYPE-R and uploading the data to the LEOMO web app, you can cross reference DSS with power, cadence, map data, and other data available to pinpoint and track minute differences, to make decisions better with more quantitative, factual data.

The thing to remember is that although DSS shows the smoothness of a pedaling motion, the causes can get very complicated since movement is part of a very holistic machine; taking account the whole body from head to toe, the bike itself, and the environment. It takes acute observation of the whole body to correctly analyze the reason for the dead spots. As shown in the previous article, there are some easy-to-understand movements that cause dead spots. However, we find that rather than attempting to quickly lower DSS, aiming to decrease DSS by slowly and methodically improving pedaling form is the better solution, using DSS as a marker — hence, motion performance indicator.


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