Is anyone else having trouble getting useful power and cadence data from a Stages Track Power Meter?
I have an old Paramount track bike with the Stages Dura Ace Power Meter, a Joule GPS computer (v19.087 firmware), a Bontrager Standard ANT + speed sensor, and a Magellan ANT + HR strap. Everything pairs and seems to play together nicely. The data are screen shots from Cyclops PowerAgent 7.7.5.
First pic is data from cadence drills on rollers. I'm on a tiny gear (43x22) working on leg speed. The exercise was 4 min warm up at 90 rpm, then a set of 6x of 30 sec at 120 rpm, 90 sec at 90 rpm, 30 sec at 140+ rpm, 90 sec at 90 rpm.
Here's a blowup of the 3rd 140 rpm interval at time 00:18
In this interval, I was probably doing ~160 rpm. I'm on rollers on a fixed gear bike trying to be smooth, but the power and cadence are bouncing wildly, while the speed (blue) is reasonably smooth. Dips in the power correspond with dips in the cadence.
Here's the next 120 rpm interval at 00:20:
The power looks reasonable, but the variability of the cadence is still a bit high compared to the variability of the speed. Other intervals show similar performance. Both cadence and power bounce wildly at higher cadence (>150ish).
So I took the bike to the track for a little training. Here's the data from a flying 200 (1.5 lap windup, sprinting down the back straight into turns 3-4) on a 47x14 gear:
More bouncy cadence data at higher rpm.
Here's data from a standing (actually slow roll) start at the velodrome on a 49x15 gear:
In this case the cadence starts bouncing around at a rather modest cadence, and the power with it since I'm assuming the calculated power is force*radius*cadence.
According to the Stages website, this power meter should be good from 0-220 rpm. I'm nowhere near the upper limit and my power is pretty modest as well.
I've tried re-zeroing the power meter (number doesn't move much) and replacing the battery (a problem I had with a powertap road hub).
I contacted Stages 2 weeks ago and while they generated a 'support ticket', I haven't gotten any help.