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Nov
30
comment DIY computational fluid dynamics for aerodynamics?
Yeah, I guess I'm "that" guy. I think your question was a little open-ended but there's an interesting bicycle-related kernel in there. I'm thinking about how best to answer the kernel.
Nov
30
comment DIY computational fluid dynamics for aerodynamics?
Defraeye et al. (2010) did some work with CFD and wind tunnel measurements, and claimed to get reasonably good modeling. Getting quick CFD is the holy grail, of course -- but the problem is "quick."
Nov
29
comment DIY computational fluid dynamics for aerodynamics?
I don't know, I sorta like the reference to "the Chung Method."
Nov
17
revised How accurate are indoor trainer power meters?
added 1124 characters in body
Nov
15
comment Is the Power Pilot the only speedometer / computer that will work on a LeMond Revolution Trainer?
An alternative to buying a Power Pilot may be to mount a cheap speedometer using the small magnet attached to the "wheel", then use the information here to calculate power for speed, print that out on a sheet of paper, and tape it to the wall next to your trainer. If you can afford a slightly nicer ANT+ capable speed sensor plus ANT+ USB dongle, you can then use the trainerroad application or Golden Cheetah to display speed and power on a computer screen.
Nov
14
revised How accurate are indoor trainer power meters?
added 7 characters in body
Nov
14
answered How accurate are indoor trainer power meters?
Nov
11
awarded  Revival
Nov
8
revised Extra power needed uphill for weight increase
corrected spelling, grammar, and shortened question.
Nov
2
revised Can Tacx Flow head unit work with old (2002) Basic frame/brake?
added 413 characters in body
Nov
2
answered Can Tacx Flow head unit work with old (2002) Basic frame/brake?
Nov
2
comment Terminology index
@freiheit: It's an English word that is also a French word. That's like saying "Paris" is an English word that's commonly mistaken for a French word. In English, we pronounce "pannier" as "PAN-yer" and "Paris" as "PAIR-iss" but in French they are pronounced "Pan-YAY" and "Pa-REE."
Oct
31
comment Why choose a traditional frame over an aerodynamically streamlined frame?
Speed increased for the same power output. Power output decreased for the same speed. Power and speed were recorded electronically at one-second intervals. The electronic recording device was not influenced by the rider's beliefs, so claiming that the estimation of Crr and CdA was the result of a placebo effect is incorrect.
Oct
31
comment Why choose a traditional frame over an aerodynamically streamlined frame?
@meagar: Exactly. But the metrics are not speed and power. The metrics are CdA and Crr. We're using a power and speed recorder to record the data in order to calculate CdA and Crr, which are independent of speed and power. In fact, it's the variance in speed and power that make CdA and Crr estimable. We could have done the estimation with a powered electric bicycle, varying the throttle and speed and still estimated CdA and Crr. Even if the rider had a prior belief it's the relationship between power and speed that matters -- and that is what is recorded.
Oct
31
comment Why choose a traditional frame over an aerodynamically streamlined frame?
First, how could "a placebo effect" alter the recorded speed and power? Second, the field test was consistent with wind tunnel measurements. How could a placebo effect affect the wind tunnel? Third, I already pointed out that it was an example comparison of two frames that were already considered aero -- I used this example because the difference was smaller than usual. We really should move this to a discussion room if you wish to continue.
Oct
31
comment Why choose a traditional frame over an aerodynamically streamlined frame?
@DanielRHicks - we can (and probably should) move this to a discussion room if you wish but these advantages don't disappear. Here's an example of a field test under real-world conditions that measured the difference between two frames that were already pretty aero. Subsequently the rider raced in a 40K TT and his actual time came within half a second per km of the predicted time.
Oct
31
comment Why choose a traditional frame over an aerodynamically streamlined frame?
@DanielRHicks - You may have doubts but the differences have been measured in wind tunnels (with rotating front wheel) and also in field tests. Whether the difference is large enough to matter is a legitimate question; but whether the frames "provide measurable improvement" is not.
Oct
29
comment What road bike tire pressure is best for speed?
There is an example of rolling resistance on real roads increasing with increasing pressure about two-thirds of the way through this article.
Oct
17
awarded  Critic
Oct
16
comment Effective breathing for efficient cycling
Unlike weight-lifting or yoga, but like running and swimming, cycling is mostly about aerobic capacity. However, the efforts during cycling tend to be much more variable than running or swimming (especially running on a flat track or swimming in a pool). That means your respiration rate is going to be much more variable than in running or swimming (or weight-lifting or yoga). Sports which are more steady-state allow for more steady-state rhythm in breathing.