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Aero, Rolling, Gravity Values on Software
Posted: Tue Jan 29, 2008 10:28 am
by wbaucino
Hi guys.
I'm new to the IBIKE and was wondering if someone could explain what the values for Aero, Rolling, and Gravity represent and how I would use them in analysing my ride. I'm sure this is an incredibly stupid question, but I have no shame.
Thanks alot.
Wayne
Re: Aero, Rolling, Gravity Values on Software
Posted: Tue Jan 29, 2008 11:47 am
by travispape
wbaucino wrote:Hi guys.
I'm new to the IBIKE and was wondering if someone could explain what the values for Aero, Rolling, and Gravity represent and how I would use them in analysing my ride. I'm sure this is an incredibly stupid question, but I have no shame.
Thanks alot.
Wayne
No, this is a good question. This is just to give you feedback on where your power is going, how much to overcome wind resistance vs. rolling friction vs. gravity. In the case of gravity, a downhill will show up as a negative loss since gravity is helping you.
Click and drag on various segments of your graph and see how the sources of resistance vary with slope and speed. This will help you see where you really need to focus on an aerodynamic ride position for faster times.
Travis
Re: Aero, Rolling, Gravity Values on Software
Posted: Sun Feb 24, 2008 4:08 pm
by dtrousdale
travispape wrote:wbaucino wrote:Hi guys.
I'm new to the IBIKE and was wondering if someone could explain what the values for Aero, Rolling, and Gravity represent and how I would use them in analysing my ride. I'm sure this is an incredibly stupid question, but I have no shame.
Thanks alot.
Wayne
No, this is a good question. This is just to give you feedback on where your power is going, how much to overcome wind resistance vs. rolling friction vs. gravity. In the case of gravity, a downhill will show up as a negative loss since gravity is helping you.
Click and drag on various segments of your graph and see how the sources of resistance vary with slope and speed. This will help you see where you really need to focus on an aerodynamic ride position for faster times.
Travis
Perhaps you could explain this a little more to newbies like me, new to both iBike and to power training. I've been using my new iBike regularly now for about 6 weeks and have been puzzled by some of these numbers. Here is a sample 5-minute segment over a 1.7 mile rolling course under fairly windy conditions:
Code: Select all
Min Avg Max
Power 0 346.8 788 W
Aero 0 264.4 1555 W
Rolling 16 54.7 70 W
Gravity -276 26.5 288 W
So does "Aero" represent wind resistance, and the 264.4 Avg and 1555 Max saying that I was overcoming a lot of wind resistance whereas "Gravity" sort of balances out as a factor with a low average and with a negative Min that is roughly the same as the positive Max? My Crr is .0064, so I guess the Rolling numbers would represent something pretty average and also not much of a factor? I read in another post that a Crr of .006 could be average.
Thanks in advance,
~David
Re: Aero, Rolling, Gravity Values on Software
Posted: Sun Feb 24, 2008 11:11 pm
by michaeltop
There is a lot of good information about forces on a rider available at
http://www.analyticcycling.com
Re: Aero, Rolling, Gravity Values on Software
Posted: Mon Feb 25, 2008 8:50 pm
by travispape
dtrousdale wrote:Perhaps you could explain this a little more to newbies like me, new to both iBike and to power training. I've been using my new iBike regularly now for about 6 weeks and have been puzzled by some of these numbers. Here is a sample 5-minute segment over a 1.7 mile rolling course under fairly windy conditions:
Code: Select all
Min Avg Max
Power 0 346.8 788 W
Aero 0 264.4 1555 W
Rolling 16 54.7 70 W
Gravity -276 26.5 288 W
So does "Aero" represent wind resistance, and the 264.4 Avg and 1555 Max saying that I was overcoming a lot of wind resistance whereas "Gravity" sort of balances out as a factor with a low average and with a negative Min that is roughly the same as the positive Max? My Crr is .0064, so I guess the Rolling numbers would represent something pretty average and also not much of a factor? I read in another post that a Crr of .006 could be average.
Thanks in advance,
~David
Yep, aero is for the aerodynamic resistance. That max of 1555 W aero indicates that at one point you where hit with a gust that decelerated you significantly.
The average 264.4 W indicates that on this portion of the course was flat enough that most of your work was against wind resistanc.e
The negative minimum gravity indicates that the ride segment included a downhill. (A negative gravity loss = a gravity boost.) The +26.5 W average gravity indicates this portion of the ride was slightly uphill on average.
Yep, it looks like your Crr is fairly typical and rolling loss is typical. It is usually the smaller component in the power equation--it just that it's alway there if you're moving.
Travis