Does cadence influence fit process?
07-17-21, 08:19 AM
#1
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Does cadence influence fit process?
I plan to monitor my fit on my bike using my phone camera and processing the data in kinovea.
The issue is that my phone records at 60fps max, this creates blurry frames when I try to track my feet at 90RPM, this creates error in the measurements of angles and distances.
I think of pedalling in a smaller cadence in order to increase the frames "crispness" and reduce the measurement errors, but in afraid that by not pedalling in my natural frequency, I may fit my bike wrongly.
Has someone have experience with a similar issue?
The issue is that my phone records at 60fps max, this creates blurry frames when I try to track my feet at 90RPM, this creates error in the measurements of angles and distances.
I think of pedalling in a smaller cadence in order to increase the frames "crispness" and reduce the measurement errors, but in afraid that by not pedalling in my natural frequency, I may fit my bike wrongly.
Has someone have experience with a similar issue?
07-17-21, 09:41 AM
#2
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The amount of power you put out will change certain aspects of your fit. Particularly how much less weight you are putting on the saddle and bars.
If you are talking strictly about taking porn shots of yourself to feed into some sort of software to tell you if you fit on your bike, then I have no idea. I'm not big on things that try to boil fit down to absolute formulas unless they are only used as a starting place.
If you are talking strictly about taking porn shots of yourself to feed into some sort of software to tell you if you fit on your bike, then I have no idea. I'm not big on things that try to boil fit down to absolute formulas unless they are only used as a starting place.
07-17-21, 05:55 PM
#3
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I don't think it matters. I've ridden the same bike as a normal road bike and as a SS bike, pedaling anywhere from 35-135 cadence. Fit worked the same at all cadences. That said, you may find that your feet behave differently at high and low cadence. At high cadence, I keep my feet flat and motionless. At low cadence I might be flexing my ankles more. Didn't seem to matter though. I'd say when you're videoing, keep your feet quiet.
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07-26-21, 07:38 AM
#4
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If you are talking strictly about taking porn shots of yourself to feed into some sort of software to tell you if you fit on your bike, then I have no idea. I'm not big on things that try to boil fit down to absolute formulas unless they are only used as a starting place.
07-26-21, 07:42 AM
#5
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07-26-21, 09:42 AM
#6
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Revisiting the topic with the solution to my problems if other also have it. Blurry images are generated by a long shutter speed, not fps.
I was capturing videos with my phone's stock camera, which adjust the shutter speed automatically in accordance with the image brightness, since I was not using sufficient lighting in my setup the shutter speed was reduced and I got the blurry result. To solve the issue I increased the lighting (filmed outdoors during daylight) and used a camera app which let me fix the shutter speed (the stock app with auto shutter speed may be enough if sufficient lighting is used).
To quantify the blurriness generated by shutter speed: 90rpm=1.5rps, this means that in 1 second the pedal travels 540°, multiplying this number by the shutter speed results the angle which the pedal travels "during" each frame. With my previous lighting setup the shutter speed was automatically set to 1/15, which results in 36° for each frame; outside in a cloudy day I was able to record at 1/2000 which results in 0.27° for each frame which is more than enough.
TLdr: pay attention to lighting when recording high speed video, stock cameras set shutter speed automatically, specific camera apps let you fix this setting.
I was capturing videos with my phone's stock camera, which adjust the shutter speed automatically in accordance with the image brightness, since I was not using sufficient lighting in my setup the shutter speed was reduced and I got the blurry result. To solve the issue I increased the lighting (filmed outdoors during daylight) and used a camera app which let me fix the shutter speed (the stock app with auto shutter speed may be enough if sufficient lighting is used).
To quantify the blurriness generated by shutter speed: 90rpm=1.5rps, this means that in 1 second the pedal travels 540°, multiplying this number by the shutter speed results the angle which the pedal travels "during" each frame. With my previous lighting setup the shutter speed was automatically set to 1/15, which results in 36° for each frame; outside in a cloudy day I was able to record at 1/2000 which results in 0.27° for each frame which is more than enough.
TLdr: pay attention to lighting when recording high speed video, stock cameras set shutter speed automatically, specific camera apps let you fix this setting.
Last edited by Matheus0312; 07-26-21 at 09:44 AM. Reason: Organization
