angusinalberta wrote:
> Bestest Handsander wrote:
> > I was looking to buy a Polar 720i when the iBike Pro popped up on my radar.
> > Anyone had a chance to play with one yet or talked to somone who has?
> >
> > After reading about it, it looks like there are a lot of caviots about
> > accuracy, but it is tempting especially for the price.
> >
> > http://www.ibikesports.com/
> >
> >
>
> I too would also like to hear from someone who's played with it.
>
> Although it's not a true competitor for the absolute power measuring
> devices it might be useful to some people for getting relative readings.
> For example it could be used to compare today's maximum effort to last
> week's even if the wind direction changed or a different road were to be
> used. It wouldn't necessarily give the same absolute number as a Power
> Tap or SRM and I'd be surprised if it did.
>
> I'd like to think of it as being just another power calculator, like
> several that are available on the net, except it measures the gradient
> and wind continuously and calculates power in real time using some
> arbitrary value of CdA. So if you use exactly the same posture on the
> bike every time it should give reasonably reproducable results.
>
> My 2 cents,
> Angus
It seems that you have to choose a position which gets calibrated into
the system by a coast-down test. This would indicate that the power
figures are really only reliable in that position. But that is only the
case when wind resistance is the overwhelming source of drag. And when
that is the case I know I am almost always in the same position anyway.
At least any time when I would be interested in knowing my power
output. In other words the likelyhood that a rider will use a different
position is offset by the fact that they are generally going slower if
they use a different position, and thus the assumed resistance is not
so great, and thus the error percentage is minimized.
To me the downside is you can't use it to easliy measure the effects of
slight position changes, nor the effects of different wheels, etc. Also
not usable on a trainer so things like home-made AT tests are more
difficult.
I also would like to see a heart rate monitor built in. And I want a
pony.
Joseph
