I have just received a cycle-ops fluid trainer and have noticed that the resistance of the unit changes for a constant speed.
When I start riding on the unit, I generate just over 300watts at a speed of about 37km/h. After about 5-10 minutes, I am generating the same power at 35km/h. I use a powertap on my bike.
This is a problem for me, as I was intending using the trainer to ride a 5k TT - like the Carmichael Field Test. This is a problem as I will get inconsistent numbers.
Has anyone experienced this? I am assuming the unit changes behaviour as it heats up.
Last time I saw one of these threads the consensus seemed to be that everybody's fluid trainers did that, indeed after about 10 minutes once the fluid heats up.
Last time I saw one of these threads the consensus seemed to be that everybody's fluid trainers did that, indeed after about 10 minutes once the fluid heats up.
I would agree, but that's opposite what the OP is seeing. He says his gets harder to pedal after a warmup (ie, same power, but lower speed).
To the OP, just make sure you do a good warmup including some brief, high-power spin-ups, before starting your field tests and it'll be fine. Or, since you're monitoring your power directly, just change the 5km TT to an "8-min TT" and don't worry about the speed. Trainer speed won't relate very well to road speed anyway.
