On yesterday’s spin, I noticed I had to lower my RPM’s to maintain the same power output. Here’s a quick email I sent to Saris support:
Hey there,I was sort of paying attention (for once) to an endurance spin I was doing on my CycleOps Fluid 2. I kept my power as even as I could but noticed I had to lower my cadence to keep the same power output. Around 30 minutes (or so) the cadence leveled out with my power output.I’ve attached a screen shot of my trainer ride (COF2 and PowerTap G3 PM). The yellow line is power and the blue line is cadence. You can see, if I would have stayed at my target cadence of 85 RPM’s, I would have started producing more power because of the added resistance (oil is thickening?).From what I gather, the fluid in the resistance unit isn’t fully warmed up until at least 25-30 minutes of pedaling @ 85 RPM’s. Have you guys come to the same conclusion?I look forward to hearing from you! Have a GREAT week and ride on!Miguel
Here’s the screen shot I sent Saris support. I’m including some notations as well:
Point A: This is where the warm-up interval stopped and my workout interval began (10 minute warm-up).
Point B: As you can see, my cadence leveled out around 31 minutes (or so).
Point C: I was satisfied the oil was warmed up and wasn’t going to get any thicker. That’s when I shifted gears to get a bit higher RPM.
I drew a red line from point A to B to show how much my RPM’s dropped to keep my power output even. I realize this is not an indication there’s anything wrong with the fluid trainer, the power meter, or human error. It’s just a simple issue of the oil viscosity in the reservoir warming up enough to give consistent resistance. I’m certain if I would have a more intense warm-up, the viscosity would have thickened much faster than 30 minutes.
In case you’re wondering, the trainer software I’m using is Maximum Trainer. They have a free version to try out and I cannot say enough good things about the software, development and support!