Left / Right Power - How do you use it?
01-01-21, 11:44 AM
#26
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I've spoken before about my friend, a cycling coach, who had years of power data before a crash that eventually led to the amputation of one leg above the knee. It took a couple of years of arduous training but eventually he matched and then exceeded his pre-amputation FTP. He doesn't worry about L/R asymmetry. He can't "pedal circles" or "pull up" or "scrape the bottom of the pedal stroke." If he tried, he'd yank the prosthetic off his stump. All he can do is stomp with his prosthetic, so he stomps down hard, and all he pays attention to is total power, not separate L/R power.
01-02-21, 04:40 AM
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At the Jerry Baker Velodrome in Redmond (Think Microsoft) Washington there is a para track rider that trains at the track sometimes. I don’t believe he is local. He is a pursuit specialist and he is very fast. I don’t know what his ftp is, but based on the pace he is able to maintain, I suspect it is up there.
01-14-21, 08:19 AM
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I don't do anything with L/R data, it's more about total power accuracy for me. I still have single non-drive side crank based power meters but currently using Assioma Duo's. Everyone knows that a single sided power meter doubles the value put out by one leg for total power. Yes, you can still pace with it, you can still train effectively with it, etc... but even a left side only power meter with +/- 1% accuracy can be 10% off for total power. To me that is a lot, I'll let someone else do the math, but no one rides a perfect 50/50 and L/R imbalance is dynamic, it changes by pedaling style, cadence, effort, etc... so doubling what one leg is doing has a big impact on total power.
01-14-21, 03:52 PM
#29
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I agree jadocs . I fully expected to (hopefully) lose interest in comparing Left and Right output... IF they were close, e.g. 52/48, 51/49. Fortunately, that's what I've been seeing - 50/50 to 52/48 is my range. So, now I have two power meters on one bike that have less of a value to me - but again, I knew this going it, and had a couple points to rationalize the purchase:
1. I needed a complete crank - arms, spider, rings, everything
2. The left arm can be moved to another bike - assuming the other bike shares the same spindle - it does. So, two bikes, two power meters.
As I understand the system I bought - Shimano/Stages L/R power meter - one PM reports to the other and the L/R balance is calculated and reported. The other arm reports power - doubled. The surprise for me (before buying) was that Stages does not take advantage of each PM's data and average them - and report THAT as the power output. That seems like an easy way to get a more accurate total power output. Maybe it's a head-unit thing - Wahoo and Garmin computers are going to do that math? A better Stages App could... maybe?
1. I needed a complete crank - arms, spider, rings, everything
2. The left arm can be moved to another bike - assuming the other bike shares the same spindle - it does. So, two bikes, two power meters.
As I understand the system I bought - Shimano/Stages L/R power meter - one PM reports to the other and the L/R balance is calculated and reported. The other arm reports power - doubled. The surprise for me (before buying) was that Stages does not take advantage of each PM's data and average them - and report THAT as the power output. That seems like an easy way to get a more accurate total power output. Maybe it's a head-unit thing - Wahoo and Garmin computers are going to do that math? A better Stages App could... maybe?
01-15-21, 10:30 AM
#30
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As I understand the system I bought - Shimano/Stages L/R power meter - one PM reports to the other and the L/R balance is calculated and reported. The other arm reports power - doubled. The surprise for me (before buying) was that Stages does not take advantage of each PM's data and average them - and report THAT as the power output. That seems like an easy way to get a more accurate total power output. Maybe it's a head-unit thing - Wahoo and Garmin computers are going to do that math? A better Stages App could... maybe?
01-15-21, 12:02 PM
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Left / Right Power - How do you use it?
I use it to identify which bike I was riding when looking at old data files:
Bike 1: Typically 53/47 L/R balance
Bike 2: Typically 47/53 L/R balance
Bike 3: No L/R balance readings
I use it to identify which bike I was riding when looking at old data files:
Bike 1: Typically 53/47 L/R balance
Bike 2: Typically 47/53 L/R balance
Bike 3: No L/R balance readings
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01-16-21, 07:07 AM
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About 7 yrs ago (I was 67) I got a fit on one of Trek's new digital devices. I didn't know they were measuring spin and leg forces. At one point the fitter said, "You are at 85% efficiency with zero imbalance in your legs. How are you doing that?" I replied, "I've always trained on rollers." His response was, "Of course."
