Tire rolling resistance

[bikemanbrent]

http://velonews.competitor.com/where-th ... tires-fast
I wonder if anyone has considered the differences in tires and how it relates to the performance of the Newton vs a DFPM.
I never concerned myself too much about tire RR , thinking a top quality racing tire is going to be as good as the next. Not even close according to this data I linked to.
Our Newtons don't allow for this level of choice when dialing in a profile-which if you take this data as solid and reliable leaves a significant amount of variability if tires or wheels are changed
from day to day or before a race or event. It would be fun to have the chance to do coast downs with some of the best and worse performers to see if it is borne out
on the road.

[brookside]

Here's another test done on a smooth roller, as far as I can tell, which seems a lot closer to the roads I ride vs the surface of the roller in the test you referenced (if I ever found myself on a road like that I'd get off it pronto, looks very unrealistic IMHO). Results have a good deal of similarity but with some interesting differences:

https://docs.google.com/spreadsheets/d/ ... gid=624765

Here's a useful compendium of various CRR and Aero tests on wheels, tires and bikes for your Newton-tuning contemplations:

http://www.aeroweenie.com/data.html

In general, I think the iBike recommendation to use a .004 is too high for good roads with good tires (high tpi and/or advanced tread compounds, e.g., Conti Black Chili, S-Works Gripton, Vitt Evo Corsa etc) with latex tubes. I use .0035 to .0037 with these combinations. As a corollary, I also believe their suggested Cda estimates are too high for a rider wearing race fit clothing with an aero frame and aero wheels (and aero tires, see above link and http://bikeblather.blogspot.com/2015/10 ... art-2.html). I use .300 to .320 for the drops position depending on the bike I'm on, but it's a guesstimate since I don't have the "coast down" feature on my Newton.

[Velocomp]

http://velonews.competitor.com/where-th ... tires-fast
I wonder if anyone has considered the differences in tires and how it relates to the performance of the Newton vs a DFPM.
I never concerned myself too much about tire RR , thinking a top quality racing tire is going to be as good as the next. Not even close according to this data I linked to.
Our Newtons don't allow for this level of choice when dialing in a profile-which if you take this data as solid and reliable leaves a significant amount of variability if tires or wheels are changed
from day to day or before a race or event. It would be fun to have the chance to do coast downs with some of the best and worse performers to see if it is borne out
on the road.

I looked at this article at some length. Though I don't think it is wrong, it's too bad they did not express the differences in terms of Crr (coefficient of rolling resistance). The watts numbers are not very meaningful, especially when they assume the rider is doing 40Km/h, something pretty difficult for a "normal" cyclist to do.