• 23rd June 2008 - By adventuresofgreg

    I sat down with the last 5 years of my SRM power data from training, the speed test results from 3 different lakes with V11G and a calculator and tried to come up with a realistic prediction of what my chances are to beat Carter Johnson’s 242 km flat water kayaking 24 hour distance record. I needed to consider what the weather conditions would likely be during the attempt, what my realistic power output capabilities are, and the differences between the surveyed course and my actual track.

    My prediction is that I will cover between 242 km and 256 km. It will be CLOSE, and it will probably be the toughest physical challenge I have ever attempted.

    When I set the 24 hour human powered vehicle distance record of 1042 km in 2006, we were able to accurately predict my potential distance before the event by testing Critical Power streamliner on the track at various power outputs using the SRM. I knew from training and previous 24 hour record attempts, that I was capable of finishing a 24 hour event with an AVERAGE power output of between 110 and 115 watts. This finishing average seems low, but it INCLUDES zeros logged from brief periods when I was not pedalling, and pit stops. My actual average when turning the pedals around was between 150 and 160 watts.

    Predicting my distance based on real average power output is basic physics. If we know what the total amount of energy that is put into the system (watts of power), the drag coefficient, and rolling resistance of the vehicle, air density and other environmental factors, then we can fairly accurately predict distance covered.

    I can do exactly the same thing with V11G and the 24 hour human powered boat distance record. If you look at the speed graph above, you will see that the curve isn’t perfectly linear meaning that using an overall average power output shouldn’t result in the same average speed that using ACTUAL fluctuating power values would. But in this case, it does.

    For example, If I pedalled at 150 watts of power for the first 12 hours, according to the graph, I would average 11.7 km / hr, and if I pedalled at 100 watts for the last 12 hours, I would average 10.1 km / hr resulting in a total 24 hour average speed of 10.9 km / hr and 125 watts of total average power. Looking at the graph, we see that my average speed for 125 watts of power is exactly 10.9 km / hr, so the graph data is fairly linear at power levels that I would normally be operating at for a 24 hour effort.

    To estimate my total average power output capability over 24 hours, I used two SRM data files: the first 12 hours from the 2006 HPV 24 hour record (the SRM battery died after 12 hours), and confirmation data from a 14 hour, 400 km training ride from Calgary to Jasper in 2006.

    My averages for the first 12 hours at the HPV record on the race track in Eureka, California was 120 watts and 568 km total distance (49 km / hr average speed). Since I finished with a total distance of 1047 km, I calculated that my second half average power would have been 110 watts resulting in a total overall finishing average of 115 watts for the entire 24 hours. I believe that with an additional 2 years of training under my belt, I am now capable of finishing with an average of 120 watts.

    You will note that there are two curves on the plot: “ideal conditions” and “5 to 10 km of wind”. In a perfect world I would attempt the record on a PERFECTLY windless day, but I am not really sure that actually exists. In reality, if I luck out and get a very good weather day, there will still be some wind and it will peak by late afternoon.

    So, using the speed curve graph and my power output capabilities, here are some worse case to best case scenario predictions:

    • #1. Worse case: 10 kph winds all day, poor average power
    • Power: 100 watts
    • Average speed: 10 km / hr
    • Total distance: 240 km
    • GPS vs actual course (-1.3%): 236.8 km (5.2 km under the record)
    • #2. Medium case: 10 kph winds for half the day, moderate average power
    • Power: 110 watts
    • Average speed windless half: 10.7 km / hr
    • Average speed windy half: 10.3 km / hr
    • Total distance: 252 km
    • GPS vs actual course (-1.3%): 248.7 km (6.7 km over the record)
    • #3. Good case: 10 kph winds for half the day, good average power
    • Power: 115 watts
    • Average speed windless half: 10.8 km / hr
    • Average speed windy half: 10.5 km / hr
    • Total distance: 255.6 km
    • GPS vs actual course (-1.3%): 252.2 km (10.2 km over the record)
    • #4. Very good case: 10 kph winds for half the day, best average power
    • Power: 120 watts
    • Average speed windless half: 11.1 km / hr
    • Average speed windy half: 10.7 km / hr
    • Total distance: 261.6 km
    • GPS vs actual course (-1.3%): 258.2 km (16.2 km over the record)
    • #4. Best case: windless day, best average power
    • Power: 120 watts
    • Average speed: 11.1 km / hr
    • Total distance: 266.4 km
    • GPS vs actual course (-1.3%): 262.9 km (20.9 km over the record)

    What I need to do to confirm these predictions is to spend about 5 hours straight going around a large lake in good weather conditions at my planned power output of 150 to 160 watts and record my resulting average speed. The objective would be to allow my overall average power to drop down to 120 watts, and then observe the total distance covered in the 5 hour test ride.


    No matter how good you are or think you are, there is always someone waiting around the corner who can show you how much you really suck.

    Orlando Borini – 24 hour road bike distance record holder 869.5 km

    In the pursuit of what is possible using human power and all of the technology available to me, I can’t help but wonder what the true limits are – that is, if we combined an athlete with world-class power with my human powered vehicle technology.

    The current 24 hour road bike distance record is owned by Italian Orlando Borini. He cycled his time trial bike an unfathomable 869.5 km in 24 hours around an airport road in Italy in 2007. I calculated that Orlando would have had to output an average of 200 watts of power to average 36 km / hr for the entire 24 hour race.

    To put that into perspective for you, I averaged the same 36 km / hr on my time trial bike at Ironman Arizona (flat course) and averaged exactly 200 watts and finished the 180 km bike route in almost exactly 5 hours. That put me second in my age group and I finished the day in 4th place. Big whoop. Orlando Bori
    no did the same thing I did for 24 hours instead of 5 !!!
    In my defence, I am 47 years old and have never taken performance enhancing drugs, nor have I ever trained or competed as a professional cyclist.

    Out of curiosity, I did an analysis of my current fitness level and I found that I am right about in the middle between an “average healthy person” and a “world class athlete”.

    First, I took my power tests and compared my watts/kg of body weight to the ‘power profile’ table and found that I have been as high as 4.2 watts/kg for the 20 minute test which puts me at the bottom of Cat 1 level cyclist. Not quite at the pro level, but pretty far from an untrained athlete.

    Power Profile

    Greg’s power test data
    Then I searched the Internet for more data on human endurance and found two graphs which confirm where I fit into the human power world using my 20 minute power profile, my 24 hour average power output, and Orlando’s world class 24 hour power. The graph below shows my data inserted right about in the middle between a healthy human and and world class athlete. I added the top line which shows power for 24 hours.

    Human power graph #1

    Human power graph #2

  • No Responses to “An honest look at my chances”

    • Alex on June 23, 2008

      Out of interest, and because my maths is truly lousy, what would happen if you put Signor Borini in your 24hr HPV, assuming he could put the same average power down when bent as when wedged?

      Although of course you might not want to put him in because that'd lose you the record.

    • Tim on June 23, 2008

      Just think Greg if you would have been a woman you'd be at the bottom of the pro Cat – you'd make a great domestiques for your captain 🙂

    • Adventures of Greg on June 23, 2008

      At 200 watts of average power over 24 hours in V11G, Orlando would go about 320 ridiculous km's. Yes, I suck. (but so do we all).

    • Anonymous on June 24, 2008

      As Apollo's trainer said to Rocky during Rocky's bout with Mr. T., "He's just a man, not a machine!". You can beat him because you have superior technology (prop vs. paddle) and the eye of the tiger! You have to get offended that he DARED to break your record and now you will show him. No more Mr. Nice Guy. Now go out and ram some kayaks in half during your practice sessions!

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