AeroPod, PowerPod and Newton

If I change the position of the iAero, do I need to redo the coast-downs and calibration ride, or is a new tilt and wind offset good enough?

I can't see where changing the iBike mount position can make any "real" difference in aero, friction, wind, etc. If you were out in the open on one side of the bars and going to the stem or vice versa I think you're fine. Of course you always do a tilt and wind before every ride anyways.

However on a TT bike if you were using some unique setup you may want to take a look at how the iAero sees the wind. That could call for a new set of coastdowns and 4mi O&B.

If you change the position of the mount, do go ahead and perform some more CD's and an o & b. You just never know.

mlennox wrote:If I change the position of the iAero, do I need to redo the coast-downs and calibration ride, or is a new tilt and wind offset good enough?

There are a couple of reasons for redoing your calibration rides when you move the iBike mount. Just to name a couple:

* The wind sensor is sensitive to how much "nose-up" or "nose-down" it is pointing, which affects windscaling.
* The wind sensor is sensitive to its position relative to the bars & stem. For example, if you move a stem mount further up or down the stem, it could have a large effect on the windscaling.
* The wind sensor is sensitive to its position relative to you. Your body, shoulders, and arms act kind of like a bulldozer blade pushing air in advance of the air stream reaching the iBike. If you move the iBike unit relative to you it can affect your windscaling.
* Riding tilt might also be a little sensitive to where you have the unit mounted.