Vector Pedals


Here’s a bit of history - I recently bought a smart trainer (Tacx Vortex) and my power has dropped by c100w vs my dumb trainer that was on a 3/7 resistance and connected with garmin speed/cadence sensor. I have adjusted trainer difficulty on the Vortex but my power output stays the same, pretty much. It’s affected my motivation as I’m not able to sustain a strong race pace anymore, regardless of trainer difficulty. However, my cycling VO2 max is increasing at 58, so something is not right.

After checking more Zwift articles, it seems to validate power better on Zwift the advice was to get a power meter for more accurate readings. So, I have purchased new Garmin vector 3 pedals as they offer 1% accuracy. They are working fine and report power via my Garmin 735xt watch and Garmin Connect.

However, my main concern is that the power recording on Zwift from my pedals is 30-50 watts lower than what is recorded via my watch and Garmin connect data. Over the past two days, I have tried:

Connecting Power Source and Cadence to the Vector Pedals
Connecting the controllable source to my Tacx Vortex and tested without Tacx Vortex as a controllable source.
Changed from playing on my Ipad via Bluetooth and switched to Mac and Ant+ for pedals and vortex
Turned off all other Bluetooth connections via Mac and Phone

I’ve now run out of options and starting to rapidly lose motivation on Zwift due to what seems technical or connectivity issues.

Can someone please advise what the best course of action is? I’m not wanting to buy any more kit, so hoping there is a quick fix somewhere?



Your power meter pedals are most likely giving you correct power readings now. Your Vortex was likely overestimating your power. A proper power meter is generally a lot more accurate than a turbo trainer unless you get a very expensive trainer.

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That is strange. I use Vector 3 for my power data. They connect to my 935 via Ant+ and to my PC via Ant+

If i look at my watch, and the power number in Zwift at the same time - they are the same Watts.

Where are you seeing this ‘30-50 W lower in Zwift’? Average power at the end? Instant power whilst riding? Are you comparing the same power reading? (ie: maybe your 735xt data screen is set to 10s Avg Power?) Do you have access to a different Garmin device? (perhaps the 735xt is the issue?)

FYI - your previous dumb trainer setup - using speed / cadence only - will give ‘not so accurate’ power data. So it’s not too far fetched to see a ‘drop of power’ when switching to actual power sensors.

Thanks Steve for your reply. I agree with you on the pedals. The issue I now have is the power reported on the pedals is not matching the power on Zwift when I am riding in-game or when I have a completed a ride on Zwift with the final stats. It’s this point that I’m not sure how to correct when I have followed the above actions?

Thanks Brett. Yes, it’s baffling me on the variances and what interrupts my ride through not concentrating on just having a workout. The watch is reporting av.3 sec power when riding. However, post ride, there is a difference on the final power stats. When i kick down the power during the ride, there’s also a bigger difference with higher watts.

I only have a 735xt as a secondary data screen at the moment.

I’m ok if there is a drop in power with more accurate power devices with my pedals but that data isn’t showing properly on Zwift now.

You can pair your Vector pedals as the power source to Zwift. I’m not 100% sure if this will let Zwift still work correctly to control the trainer (still pairing the trainer as fontrollabley), but perhaps someone else can confirm that. Or you can just try it.

Thanks for the advice, Steve. Yep, i’ve connected the pedals as the power source and cadence on Zwift and added the Vortex trainer as the controllable source for the resistance benefit. Once they are connected and i start riding, the power reading on Zwift is less than the power on my pedals that’s being recorded via my Garmin watch and with the post ride results. I also turned off SIM mode with the trainer as the controllable source to see if this was an issue but the difference in watts between Zwift reading and my pedals readings was even greater.

Hopefully someone in support at Zwift can help.

I do not believe it is a Zwift issue, I have a Tacx as controllable and powermeter for power & cadence and had never problems (Tacx Neo, power2max NG Eco).

To be sure everything is correct I tested this configuration (connecting with ZC) with another app (Jester), connecting with Tacx’s power and cadence, ANT+. Everything OK for me, there were some less Watts on Tacx as expected (chaindrive loss - NG Eco is a spider PM).