I just started Zwifting an I love it. Today i did my first FTP test and I hit 299 watts on average for the 20minute duration. just for sanity sake I would like to ask you guys some things to test whether my smart trainer is reliable, due to the fact that this number seems a bit high to me.
Details:
Smart Trainer: Tacx vortex
Length: 193cm tall (6"3)
Weight: 95kg (210lbs)
Experience: Been Cycling for a year now; Mostly active for 2-3 weeks and than I stop cycling for about 2 months.
Distance Cycled 2021: 431km
I did calibrate the Tacx and tires are pumped up till 8 bars.
Fitness: I haven’t been very active during the lockdown … .
Is 300 watts reasonable for someone with minimum cycling experience but rather high weight/length ? Any advice is appreciated since I have never worked with watts before and I would like to know what is reasonable.
It’s possible it is inflated it’s also possible it’s accurate. Take your watts (299) and divide them by your weight (in kg). Here is a chart of average FTPs by duration that may help determine if your number is reasonable
It’s certainly not unreasonable for a healthy and fit young person to put out the levels of power that you report.
Given your weight (95kg), an FTP of 299 gives you a power/weight ratio of about 3.14 w/Kg. For reference, that would put you towards the top of Cat C cyclists. (Cat A riders are generally 4 w/kg or greater.)
The other thing to keep in mind is this: Could you really ride at 299 watts for an hour straight? The ability to put out FTP-levels of power for extended intervals is often the difference between a trained athlete, and a merely very fit regular person. I know what my FTP is, and to be honest I think I’d struggle to hold that power for an hour straight.
Lastly there is the issue of how accurate your trainer is. It’s a wheel-on model, and those can be less accurate than direct-drive units. It’s impossible to say how accurate the numbers are. The ultimate test of how powerful you are as a cyclist is (at least in my opinion) comparing the numbers you get on your trainer with your outdoor, real-world performance. If you have access to Strava, you might want to find a local road segment, ride it, and see how your performance compares. (You’d need a bike computer with GPS to do that.) If you can climb a ± 2 km hill at a rate that Strava tells you is equal to about 300 watts - then that is probably the best “test” that the FTP you are seeing on Zwift is reasonable, if not necessarily 100% accurate.
Hi. I use a TacX Vortex and suspected the same thing at a similar power range. I recently purchased a pair of Favero Assioma Duo pedals and compared the two power outputs side by side over different power ranges.
Firstly, before I calibrated my Vortex the power numbers were way out (I went outside in the cold for the first time in ages to do this test). I recalibrated and the wheel tightness was just below the maximum recommended level. I also then calibrated the pedals.
After calibration, I found the Vortex did significantly inflate the power numbers, and this amount varied depending on whether I was doing 150W, 200, 250, 300 or 350W.
On average I found the difference was between +20 and +30W. At the 300W range it was closer to 30W difference.
A friend of mine has the same trainer, but he found the trainer reported similar power to his PM. So this result isn’t fool-proof.
Anyway, don’t be discouraged if your FTP is actually 30W less than you first thought. 270W is still really good for a beginner. Regardless, I’ve found the trainer to be consistent and with that in mind you can reliably use 299W as your FTP and get some good gains from a training regime.
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