AeroPod, PowerPod and Newton

Apologies if this has been answered before but I can't find it on the forum.

It's reported in the media that ovalised chainrings result in higher than actual power readings and as DFPM are the majority of the market I'm assuming this is how power is being measured in these reports. My question is does the PowerPod suffer from this over reading of power if you're using oval chainrings?

(My hunch is it doesn't because it is calculating the force required to move the bike forward based on the resistance to that forward motion and I can't think how this would be effected by oval chain rings.)

Your hunch is correct. PowerPod measures opposing forces, so it doesn't have the problem of trying to interpret torque measurements. It does not over-report watts when used with oval chainrings.

Thanks John. Makes sense but I just wanted to get confirmation.

usedtobefaster wrote:Thanks John. Makes sense but I just wanted to get confirmation.

Is "power stroke" available for the PowerPod?
I'd be interested to see some before/after images with/without oval rings.
(We've used it with 'Doval' rings and not noticed much difference)

Yes, PowerStroke is available for PowerPod.

http://www.powerpodsports.com/shop/powerstroke-upgrade

Pete,
Not sure if this is what you are after. Two snapshots from separate rides, one with round ring and one with Rotor Q-Rings.
Worth noting that the Q-rings are on my Tandem, so nearly 350lbs on the roll. This bike also has the newer Garmin cadence sensor that doesn't have a mounted magnet so I've left the sensor location "Not Set".
The tandem is very stable side to side but with two sets of legs pushing there is a lot of fore/aft motion. The Q-rings add to that somewhat, but this particular ride it was windy and we fought pretty hard to maintain speed. I can load the entire file if you like, but the picture tells the story.
The round ring is from a quick ride (got too cold and went home) on my fixed gear bike.
Cheers,
John