Patrick Gilmour said:
Are the iBike solutions really that unreliable? I thought for a non-pro the Newton was meant to provide pretty accurate results. Is it just marketing hype?
There are what I consider to be serious issues with iBike that keep it from being considered on par with SRM, Quark, PowerTap, or even Power2Max:
- iBike is very sensitive to calibration. The unit requires a calibration for the angle at which it sits on the bike which is sensitive to error if the bike is not perfectly vertical when the calibration is done.
- iBike requires coast down calibration to determine coefficients for bike/rider drag and for rolling resistance. This calibration is very sensitive to changes in wind velocity (i.e., speed and direction). This calibration can also be sensitive to changes in pavement condition and road slope. It's very difficult in most places to get constant wind conditions over the course of the calibration.
- iBike does not read power well in a peloton.
- iBike's mount is relatively inflexible, especially for stem mounting.
Newton has apparently tried to resolve some of those issues, but I'm hesitant to believe those issues are gone. In theory, iBike, in perfect conditions, will work as well as other units, but perfect conditions must include constant road surface, constant wind, perfect calibration, and a rider that never changes position. For the cost of a Newton, you're almost half-way to getting a
Power2Max and well within range or closer to the price of used PowerTaps, Quarks, and SRM's on eBay. Certainly there are used PowerTaps on eBay for the $500 ballpark.