Power difference between HT and real world

General Discussion
1

Hey everyone,

I’m very new in the Zwift community and I’ve just started to train on home trainer since a few weeks now.
My HT is an Elite Direto XR-t for information, fully calibrated on app and with correct wheel circumference, maybe it will be helpful for any help.

I just had a race on Zwift, last friday in the “A” group where I could ride a wonderful 41kmh avg with 280W avg on 28kms… The thing is, I weight 60kgs, and during my real rides I’ve never get above 190W during 40kmh when I push hard too.

I think the difference is veeery huge. Did some of us experience the same thing on same or different HT ?

2

You have calibrated the trainer correctly as you said?

If so and it’s still doing that the enjoy it, rip up those A grade events. (Note sarcasm)

If you want to train to get better then you obviously have to do more research and reach out to the manufacturer to find more details.

Do you have power meter that can also measure power too? Can you use that?

It should be fairly accurate: Elite Direto XR/XR-T Smart Trainer In-Depth Review | DC Rainmaker

Outside you have coasting too, and you have corners , traffic lights, etc.

3

Hello Chris thanks for your answer.

Yes I have calibrated my HT twice in just a week, and it’s relevant comparing to default calibration value.

I don’t have power sensor unfortunately… I’d like to in order to compare yep…

I will see in my future rides if my HT still thinks I’m Pogacar, otherwise as you say I should contact Elite support yes!

Ty for your advise !

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4

How close is your calibration value to the factory value written on the bottom of the trainer?

5

Hey Steve, thanks for replying

The default value was 6440 and after calibration it’s now 6444

6

That should be close enough.

You say you don’t have a power meter, so how do you know your outside power that you’re comparing with the trainer?

7

These power values are calculated with the deep and dark Strava algorithm, I don’t know if these are accurate. Btw the speed difference is important too, like 41kmh avg on HT race and 34kmh during tempo outside ride.

Maybe just the HT condition are better and smoother than outside rides

8

I think you shouldn’t worry about your trainer being inaccurate if you’re only comparing it to Strava.

2 Likes
9

Okay, you’re probably right, I’d better test with a power sensor.

Thank you for your time Steve :slight_smile:

10

Strava makes an assumption, but when riding outside you don’t blast downhill at 280w+, most people I know are happy to soft pedal down hills, then you have corners, or slowing for cars, people walking, dogs, kangaroos (I’m Australian) or whatever else.

I wouldn’t really trust them. A friend of mine does track cycling and most times when he’s completed the 160 lap training event at some 46km/h average, he ends up with strava power quoted at something like 450 watts… He’s powerful, but not that powerful. :wink:

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11

Okay, that’s the real difference, during virtual race, I was pushing all along with no breaks, maybe the power estimation was right

Ahah okay, thank you for the feedback :joy: Okay, then I should more believe my HT than Strava in terms of raw power

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12

stravas power estimation is absolute bobbins in its estimation, at best indoors and outdoors hit just over 800w as a peak max power, when I go out on the gravel or mountain bike it has estimated me to hit well over 1000w when it has no power meter to look at

13

Hey @Thomas_Sinan,

I took a quick peek at the reporting for your account, and it looks like there are a few Bluetooth disconnects on your rides. Looking through some of the internal reporting from the Zwift servers, I’m also seeing some higher than expected RSSI values which indicate there might be a bit of wireless interference. between the interference, and the dropouts it can absolutely cause some slight power spiking.

We have an awesome basic troubleshooting article for interference, take a look and see if anything seems like it might be affecting your setup.

14

Hey Terry, thanks for answering.

When you say few, like more than average ? During the race for example ? How many disconnections have your reported? That’s really weird

I’ll give a check to you article, maybe I should consider using an Ant+ key too

15

Assuming you are not running on Apple TV, you can upload log files to zwiftalizer.com and it will visualize the dropouts for you.

1 Like
16

Ohhh what a tool ! Thanks!! I’be loaded my last race and any BT disconnection had been detected, but a I found few UDP packets in timeout maybe it affects my perf a bit (but I’m not really sure of it)