power on the trainer vs rollers

workingguy said:

For those who ride inside a lot or just understand roller dynamics...

About a year ago my best 10 was 270 on the CycleOps Fluid 2. FTP at that time was around 210, also on CycleOps. I had no consistent training plan whatsoever.

Past 5 months or so, I've been doing steady 2x20s L4 with some L5, except on Kreitler rollers with headwind fan and 2 flywheels. Now when doing L5s, I can barely maintain 270 for 5 minutes, forget about 10. FTP now is 240, on the rollers. I stopped using the CycleOps because of squirrelliness after riding them too much.

Power is supposed to be the equalizer, but why was it easier to generate power on the CycleOps and PE on the rollers much higher for the same power. I gained in FTP, but did I lose VO2max power?

One explanation could be it has to do with the position you are in, assuming they have similar calibration. If you were riding more open on the cycle ops you would have more power than if you are riding more aero on the rollers. At least that is one explanation.

one possible explaination might be that you've been doing almost purely threshold work for 5 months straight and virtually not An Cap... you've lost your capactiy to anaerbic capacity.. the shorter the effort the greater affect AC is going to have... much greater for 10min compared to 20min... probably has nothing to do with rollers or trainer and everything to do with your narrowly focus training for the last 5 months...

workingguy said:

...Power is supposed to be the equalizer, but why was it easier to generate power on the CycleOps and PE on the rollers much higher for the same power....

I don't have a headwind unit on my current rollers, but I can regularly generate more power during L4 intervals on my KK trainer and I don't even attempt L5 work on the rollers. That's partly because I have to spin so dang fast to get power into those ranges without a headwind unit but partly because of the extra attention I have to expend while on the rollers to stay upright. The mental energy I expend staying smooth and centered on the rollers is energy I could be directing into the pedals with no worries on the KK trainer. Yeah, it's not energy measured in kJ or watts so it probably shouldn't detract from my FTP estimates but it does since I'm not willing to go all out or direct all my attention to my PM while riding the rollers. I notice Ric advises folks not to use rollers while attempting one of his MAP tests. I always suspected his reasoning was similar, use a trainer so you can go all out without worrying about riding off the rollers. 'Could be wrong there but that's the way it looked to me.

Anyway I can't think of a physical or physiological reason other than those already offered. After all a dynamometer is basically a set of rollers, but then a car doesn't have to worry about falling over and crashing into the TV set 🙂

workingguy said:

About a year ago my best 10 was 270 on the CycleOps Fluid 2. FTP at that time was around 210, also on CycleOps.

It's seems pretty atypical to be able to hold 128% of FTP for 10 minutes. It's possible that your FTP was understated before.

workingguy said:

For those who ride inside a lot or just understand roller dynamics...

About a year ago my best 10 was 270 on the CycleOps Fluid 2. FTP at that time was around 210, also on CycleOps. I had no consistent training plan whatsoever.

Past 5 months or so, I've been doing steady 2x20s L4 with some L5, except on Kreitler rollers with headwind fan and 2 flywheels. Now when doing L5s, I can barely maintain 270 for 5 minutes, forget about 10. FTP now is 240, on the rollers. I stopped using the CycleOps because of squirrelliness after riding them too much.

Power is supposed to be the equalizer, but why was it easier to generate power on the CycleOps and PE on the rollers much higher for the same power. I gained in FTP, but did I lose VO2max power?

How are you measuring power? Have you used the same power meter all along?

Power meter was the same hub, different CPU. The previous one died because of bad contacts. It would fade out whenever I reset or even if I had a big change in power, like with intervals.

I can do all the way up to L6 reps, for me at 325. With the fan it only takes 17-18mph to get L6. The flywheels add some resistance, 20-30W. My cadence for L5/6 is around 95-100. At about 110 I start bouncing too much.

Think I will just throw out those old CycleOps numbers as invalid. The rollers allow me to learn to generate power while keeping good form. FWIW, I've heard of the analogy to freeweights vs. nautilus. Some of the effort goes into balancing and keeping the bike upright. Hopefully my L5/6 power on rollers will improve if I start doing block training.