Power Tap readings on fluid trainer

peterwright

I have been using my PT sl on my a Cyclops fluid trainer and have noticed that the power readings seem to be about 50w light. I am using HR and RPE as well as my road power readings as a reference. I figured thismight have something to do with the fluid system of resistance ?? Can anyone shed any light on this.

Thanks

Peter

Woofer

Ignore your HR. Do a quick stomp test to verify your PT accuracy. Then make sure you zero it. If it's one of the early SL's it could be going bad or your trainer RPE just doesn't match your road RPE.

peterwright

Thanks for the response - how do I do a stomp test and zero the unit ?

Surely 300w on the road will feel the same as 300w on the trainer in terms of intensity and HR ?

Woofer

Stomp test here -
http://www.midweekclub.com/powerFAQ.htm#Q23

One should zero the PowerTap CPU before every ride. Put the cursor on the Power or top line. Then hold the right or left button (can't remember which as I am at work) until the mode changes from power to instantaneous torque. When one takes one's foot off the pedals at this point, the instantaneous torque should be zero. If it is not, hold down the left or right button (can't remember which) for two seconds to set the zero to the current offset. The PowerTap has a built in zeroing function but it only works within a small range and large temperature changes have to be overridden manually.

There's a thread with some posts on heart rate and riding the trainer, I'll link it when I find it, but due to plenty of natural ventilation while riding versus very little ventilation indoors even with lots of fans, heart rate will typically be higher indoors for the same effort after sufficient warm up. Also consider that heart rate is not the most useful data here. It is only a measurement of the body's response to the primary thing you want to improve, power output. Heart rate responds so slowly to sprinting that it is I would hope it is absolutely useless for that in your training versus power.

Read the entire Power FAQ.

rule62

Watch your watts. They aren't kidding about that 725 watt max rating. I was doing stomps in earnest and blew the bejeezus out of the seals. It's off to CycleOps for warranty replacement as we speak.

frenchyge

Wow, 725 is the max for the Cyclops Fluid trainer? I'd like to upgrade to fluid this winter and was trying to decide on a trainer. I was already a little skittish because of the common leakage complaints, but this may have just sealed the deal. The Kinetic website says their trainers are rated to 2500 watts.

I figure once I blow one of those babies up I'll be ready for le Tour.

RapDaddyo

Yeah, 725 is a limiting factor. I don't consider myself a strong sprinter and even I can get my power up >725. I'd be okay with a limitation of 1K watts, but 725 is a bit restrictive.

Woofer

I am so wobbly when going all out that I don't bother trying to do sprint workouts on a trainer.