Can Zwift receive power from a power meter and control the Smart Trainer resistance at the same time?


(Salvatore Iovene) #1

Hi,

I’m considering getting the Tacx Neo smart trainer, but I would want to still use the power as it comes from my Garmin Vector power meter, for obvious reliability and repeatability reasons.

 

Is Zwift able to control the Neo’s resistance according to the simulation parameters, while using the Garmin Vector as the power source, instead of the Neo?

Thanks in advance for the answer!

  -Salvatore


(Thomas Ashley (Pack)) #2

I’ve got the neo and it changes the resistance even though I’m using my stage power meter. 

Neo is a great setup, think you will be happy with it. 


(Eric C. (Zwift HQ)) #3

Hi Salvatore,

We currently do not support this set-up as we have encountered issues with its implementation. It’s on our list to be supported, however.


(David Gordon) #4

Ah, so I am unable to use my Kickr as a smart trainer with my Stages as the power meter?  I thought I couldn’t connect to the stages due to its distance from my PC and have a USB extension cable on the way, but it sounds like it is intentionally blocking me due to Zwift identified issues that are yet to be resolved?


(Eric C. (Zwift HQ)) #5

Correct. We had it before but both the power meter and the smart trainer reported power differently and the program kept trying to hold ERG mode to one but read data from another.


(Sunil Savkar WBR (C)) #6

Is the disconnect in the way the trainer interpolates or the way Zwift was sending the request to the trainer.

I would think there should be a “simple” (never is though I admit) fix which is to allow a user to train Zwift to ascertain the average difference in power as between the power meter being used and the trainer at a specific cadence and resistance point.  For instance, perhaps require a rider in a small test to maintain a cadence of say between 90 to 95, and then take the different feedback from the trainer as to power versus the pedals as to power, and ascertain that different over a period of say 2 minutes for any set resistance level.

Then over a period of say 20-30 minutes, as the resistance is varied for the trainer, you should be able to develop a profile that can be specific to that power meter/trainer situation and use the differential information to try to more truly allow a translation of power readings from the power meter into the requested level of resistance or power being required from the trainer.

I admit as I have been doing workouts in ERG mode, the differential between my powertap P1 pedals and the trainer is often about 10W different, but not always.  Seems to get closer at higher resistances, while being furthest apart at the lower power requirements and lower resistance levels.  That with keeping my cadence in my case between 95 to 100.

Anyway, something to potentially test out and see with some variation of trainers/power meters, how the profile starts to look.  but I suspect similar to having to calibrate for power meters and for trainers, you would need a method to allow the user to calibrate once for their setup (and then again if they change their setup).

 

Heck if this worked I would happily be thrilled to do a 30 or even 1 hour ride to get the differnential ride across a variety of situations so I could then ensure I could use my power meter as the power source so there is consistency in indoor and outdoor rides and readings.


(Sunil Savkar WBR (C)) #7

In another post FYI someone pointed out to me if you have a KICKR, you can just route things using the Wahoo app so that the KICKR reads power from your power meter and thus even though you select the KICKR as your power source and your smart trainer, the power readings end up coming from the power meter.

I tried it this eve on a ride and it does appear to work.  So at least for those with KICKR (or in my case a KICKR Snap), this appears to be a viable work around to the issue with being unable to directly use the power meter as a power source with the smart trainer while in ERG mode.