Page 1 of 1

Calibration in gusting winds?

Posted: Tue Nov 11, 2008 3:04 am
by nreimche
Just a quick and to the point, and maybe dumb question: Is there a way to do CoastDowns and 4 mile rides in gusting winds? It seems I always get a high wind scaling, like a 2.9, even when it's not gusting that bad. Also, since it (wind scaling) was so far off I tried to select a portion of the 4 mile ride, instead of the whole 4 mile ride. I highlighted little bits of the out and back ride, until I found a number for the wind scaling that was within the guidelines of .8 to 1.2 or a near 2 at the highest. Is this acceptable and (in)efficient? Sorry, for so many questions, but I have not seen these answers in the forum since the topica forums. Thanks for any help anyone can give.

Re: Calibration in gusting winds?

Posted: Tue Nov 11, 2008 10:14 am
by coachboyd
If you are consistently getting a high wind scaling numbers then it could just be your unit. Are your cda numbers reasonable?
If you highlight just certain sections of the ride then you risk the wind scaling not being right since you are not comparing out and back (this will directly affect your cda and could make it wrong). If your cda numbers look reasonable, then a 2.9 wind scaling is perfectly reasonable.

Is your iBike on the handlebars or the stem?

Re: Calibration in gusting winds?

Posted: Tue Nov 11, 2008 10:25 am
by travispape
nreimche wrote:Just a quick and to the point, and maybe dumb question: Is there a way to do CoastDowns and 4 mile rides in gusting winds?
No, if the wind is gusting, it really messes up the coastdown results and it will be frustrating. It is better to wait for a calm conditions, or at least steady wind conditions. I love using http://www.weather.gov/. Plug in your zip code and then click the link near the bottom-right "Hourly Weather Graph" (e.g. http://forecast.weather.gov/MapClick.ph ... =graphical). It gives detailed forecast of wind conditions along with everything else.
nreimche wrote:It seems I always get a high wind scaling, like a 2.9, even when it's not gusting that bad. Also, since it (wind scaling) was so far off I tried to select a portion of the 4 mile ride, instead of the whole 4 mile ride. I highlighted little bits of the out and back ride, until I found a number for the wind scaling that was within the guidelines of .8 to 1.2 or a near 2 at the highest. Is this acceptable and (in)efficient? Sorry, for so many questions, but I have not seen these answers in the forum since the topica forums. Thanks for any help anyone can give.
Sorry, you need to highlight a proper out&back section of the ride since both riding_tilt and wind_scaling are calculated based on the selection. For the purposes of the wind_scaling, it is important that your selection be centered on your turn-around point. Also, the size of the selected portion of the ride needs to be at least 2 miles long--4 miles would be better.

Re: Calibration in gusting winds?

Posted: Wed Nov 12, 2008 7:27 pm
by nreimche
I am asking those who are confident in their Ibike, because of my lack of confidence in my PARTICULAR unit. My thorn resistent tubes are about 3 times thicker then standard butyl tubes (for base training or when, ultimate, speed is not desired!). Does that explain a Crr of .01? I'm not sure of the weight of latex tubes. Again, I am wondering if I got a good calibration, would the crr be reasonable due to thorn resistent tubes? Oh, and not mention, I also use cheap/heavier tires, so I am less likely to have an interrupted workout and save my race tires for racing.

In case I gave too much info, my main question is: Due to thorn resistent tubes, my lack of confidence in my Ebay bought Ibike and past calibration results, heavier tires... is a Crr of .01 reasonable? I hope this none of this is any consolation to Velocomp, who has good intentions and is innovative!

Re: Calibration in gusting winds?

Posted: Wed Nov 12, 2008 7:59 pm
by coachboyd
Sure, with really thick tubes and tires, especially with a puncture resistant rubber, a crr of .01 is perfectly reasonable.
I have seen plenty of people who use heavy tires with crr numbers of .008, and that's not much higher than my good mileage clinchers that consistently give me .006. I can see where your tires would be at a .01

Re: Calibration in gusting winds?

Posted: Thu Nov 13, 2008 1:11 am
by nreimche
Thanks for your input Coachboyd. I feel a bit better, since my warranty expired recently. How much do you charge for coaching?