No, that is not what I think. As stated above Hull paper 1992 said previous data was bad.
“To date, there have been no human performance studies that test the validity of optimization analyses. The human performance studies cited earlier had deficits in that subject populations were generally...
I agree. There is room for improvement and it doesn't seem that measuring angular velocity with more resolution would cost much more but that is the only thing I can think of why it hasn't happened in consumer models. Power meters range from about 750.00 to 4,000. dollars. You would think at...
Recently, I was reminded about Riemann Sum or the area below the sine wave https://en.wikipedia.org/wiki/Riemann_sum needs to be taken into account in figuring out the mean. This would raise the average power of a revolution a little higher.
This explains why no power meter measuring once per...
My take on measuring non-round chainrings
The change in chain distance that matters is where the chain engages the top of the chain ring and the chain is pulled, transferring force. On non-circular chain rings your leverage is changing and you are trading force for speed or speed for force as...
One of the concerns that people had was inertial load effects on crank velocity especially non-circular chain rings. While the two studies below are with round chain rings, inertial load is not a problem with non-round rings as I will explain in a subsequent post.
I don’t have access to the...
So a lot of conversation on this topic happened on another more bicycle specific forum. I will be hopefully balanced.
I actually didn't quote or misquote the paper. The quote comes from Rodrigo R. Bini and Frederico Dagnese in 2012
"Noncircular chainrings and pedal to crank interface in...
That is a big assumption even with round chain rings.
"Using a circular chainring, the instantaneous velocity of the crank varies ±22% for an average pedalling cadence of 90 rpm” Hull ML, Kautz S, Beard A. An angular velocity profile in cycling derived from mechanical energy analysis...
I just saw these posts. Wait Alex, so you are saying that the chain and chain ring are holding the spider still? No it being attached to the crank arm attached to the bottom bracket?
There are multiple ways to hold the crank arm horizontal with the chain rings on. There is the other crank arm...
I agree power values can be calculated without knowing crank position. I agree you can sync crank arm position and wheel position even with a free wheel. This happens with ergs and indoor trainers. Power is calculated at the rollers where the tires press against. The resistance can be set or...
I agree except that it disconnects the wheel velocity from the crank velocity so if you are trying to find out how a person makes power within a rotation of the crank you can no longer no where the pedal crank is. In other words if you start out with wheel and crank arm perfectly in sync you can...
Sorry for the very delayed reply. Just very busy. First you probably know more than me about measuring power in general on all sorts of devices.
As far as measuring the continuous wheel speed, one thing you need to realize is that most bicycles have a free wheel so that wheel speed doesn't...
You have it right, except I was just trying to get within the error rate with least amount of sampling and measuring rotation only once a pedal revolution.
There is no problem with grossly oversampling except outside of a lab it has not been done that I know of. Since most cyclist bike outside...
I need to correct my above post for the sake of giving correct information and that this thread shows up to high in search engines when searching for topics along these lines. The main correction is there are eight points of power sampling you have to worry about to get a correct average power...
There was actually a chain tension power meter invented and in production mid 1990s to about mid 2000s. Invented by the Cote brothers and sold by polar. It sensed chain tension acoustically like a guitar pickup, a chain speed sensor pulley on the back. I will show pictures below.
They have...
Sorry, I didn't mean to leave that out. I made a mistake in implying it in the example. Currently crank base power meters are made with 4, 5, and 8 strain gauges. But I figure above 4 strain gauges help in only certain times like stopping.
So I think I figured out what these power meter...