Login required to started new threads

Login required to post replies

Tacx Neo Erg Mode Slow to Respond
Quote | Reply
I picked up a new Tacx Neo and set a bike up on it for first impressions. Fired up TrainerRoad and started riding in ERG mode. I've noticed that there is a smoothing and lag to the power when I should be holding steady. If I'm trying to ride at 300W, It will drift down to around 285W before heading back toward 300W. Similarly, it could let me pedal up to about 315W before correcting back down. I watched the power on my Garmin read and AP over the segments was off too because of this. Anyone have any advice? By the way it does the same thing in Zwift, so its not the PC settings in the software I don't believe.
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [turdburgler] [ In reply to ]
Quote | Reply
turdburgler wrote:
I picked up a new Tacx Neo and set a bike up on it for first impressions. Fired up TrainerRoad and started riding in ERG mode. I've noticed that there is a smoothing and lag to the power when I should be holding steady. If I'm trying to ride at 300W, It will drift down to around 285W before heading back toward 300W. Similarly, it could let me pedal up to about 315W before correcting back down. I watched the power on my Garmin read and AP over the segments was off too because of this. Anyone have any advice? By the way it does the same thing in Zwift, so its not the PC settings in the software I don't believe.

I've found that different chainring/gear combos result in different levels of fluctuation in erg mode. I usually put my bike in the small chainring and middle gear in the cassette for a straight chainline and minimal (but not zero) fluctuation. The bigger the gear I'm in, the more fluctuation in power I get.

---------------------------------------------------------
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [turdburgler] [ In reply to ]
Quote | Reply
It's a Tacx thing and ruins a nice machine.
It seems as though they leave on some of the virtual reality stuff when in erg mode which is just stupid.
Try putting your weight in at 20kg and it will respond much quicker.

Don't know why they just cannot give it instant response, the hardware is capable of if and it makes testing in erg mode useless.
If you are trying to do a step test and have it set to 330w it will go up to 370w before it settles down, and that is enough to totally kill your legs if you are at your threshold.
Tacx machines are nice hardware, but the firmware is crap.

I know it is capable of doing it right because it has done in the past depending on update.
Trouble is buyers are beta testers and Tacx don't listen to complaints.

It's a pretty machine that is quiet and is fun riding around in virtual mode, but for serious training or testing it is whack.
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [lyrrad] [ In reply to ]
Quote | Reply
 
Hmmm... my experience is pretty different from yours. Here's the power curve (completely unsmoothed) from my last trainer workout in Zwift on the Tacx Neo. When jumping from one power zone to the next, it will take a couple of seconds to settle down, but once in a zone I find it's only wavering by 4-5W unless I do something like get out of the saddle or drastically chance cadence. Most of the big spikes in the middle of the long sets are because I got out of the saddle to give my arse a break.




---------------------------------------------------------
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [jkatsoudas] [ In reply to ]
Quote | Reply
What weight have you entered?
Can you please try to enter 95kg and see how it responds?
What firmware version?
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [lyrrad] [ In reply to ]
Quote | Reply
I used my actual weight, 72kgs. Just to be clear, are you suggesting I change my weight in TrainerRoad/Zwift?

Tacx Neo is running the most up to date firmware and TrainerRoad/Zwift are up to date as well.
Last edited by: turdburgler: Oct 12, 17 4:01
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [turdburgler] [ In reply to ]
Quote | Reply
I know why a similar problem occurs on Wahoo Kickrs so while I haven't ridden a Tacx I can take a punt at the answer.

The issue is related to where the trainer measures power relative to the fly wheel and how software tries to correct for this. At least on the wahoo power is measured post-fly wheel (I'm not sure that's the technical way to describe it) which creates a substantial offset between your power and the measured power when accelerating and deceleration. This effect is partially corrected for in the software of the trainer but that causes a knock-on effect when using software to control the trainer. Basically you don't want your trainer to actually hit the target power and instead the trainer guesses the power it needs to hit. [This is based on fly wheel acceleration calculation so rider weight will come in as previous posters have noted.] For a more complete discussion see: https://support.zwift.com/...lywheel-Compensation.

I was really disappointed when I first tried a kickr on zwift as the effect is very substantial. One way around this issue is to use an actually power meter (rather than the trainers power meter) as an input into the computer, but it raises the question of why they bother putting an expensive power meter in the trainers to begin with.
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [jkatsoudas] [ In reply to ]
Quote | Reply
jkatsoudas seems to be on the right track. So far going in to the small chain ring and using smaller gears appears to help. The affect is still there, just lest pronounced. I am seeing a +- 10W variation at this point, maybe a bit more. Still frustrating. Any other ideas are welcome.

I tried the suggestion about changing weight and I didn't notice any difference.
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [turdburgler] [ In reply to ]
Quote | Reply
The next question is - are you using the power from the Neo or are you controlling the Neo with a power meter via powermatch? If the latter, you will see a much greater degree of fluctuation (i.e. reality).

People always seem to think that ERG mode should look like the ERG mode shown by a Kickr. That's not true. As per DC Rainmaker's comments on that, the Kickr is reporting the power it is being told to hold, not the actual power being produced, hence why it looks so smooth. On power match mode the trainer is responding to the power you are actually delivering to the pedals, as measured by your power meter. No one pedals smoothly and +/- 15 watts is certainly within the realms of a normal power fluctuation.
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [lbmxj560] [ In reply to ]
Quote | Reply
So far I've only used power from the Neo. My powermeters that I trust are in wheel hubs. I have a Garmin Vector 2 power meter pedal set, but I don't use it because I don't trust them. They are decent up until about 320W. Above that and they start really over-reporting so I'd rather not use them to PowerMatch.
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [turdburgler] [ In reply to ]
Quote | Reply
I decided to validate my theory in today's Zwift workout. After the initial warm-up intervals, there were four 5-minute intervals. I did three of these in the 34/23 and one of them in the 50/11. Can you tell which one was in the big chainring? Besides being FAR "lumpier" the 50/11 was also noisier and more vibration. In short, there's no reason I can think of to be in the large chainring when in Erg mode on the Neo.



---------------------------------------------------------
Quote Reply
Re: Tacx Neo Erg Mode Slow to Respond [jkatsoudas] [ In reply to ]
Quote | Reply
jkatsoudas wrote:
I decided to validate my theory in today's Zwift workout. After the initial warm-up intervals, there were four 5-minute intervals. I did three of these in the 34/23 and one of them in the 50/11. Can you tell which one was in the big chainring? Besides being FAR "lumpier" the 50/11 was also noisier and more vibration. In short, there's no reason I can think of to be in the large chainring when in Erg mode on the Neo.
I bought a Tacx Flow Smart last month. This weekend was the first real time on it. Really a nogo. I had bought into the marketing that in ERG mode it would follow TrainerRoad workouts with reasonably fidelity. But instead, it was all over the damned map. I tried to use my Quarq cranks to be the source of the power info and then TrainerRoad would be able to adjust the Tacx to meet the power #'s coming from the crank. Total fail. The amount of resistance in ERG mode varied hugely. It would not settle down for nothing. It was a complete fail.

So then I tried to do it again w/o the added complexity of the crank. I tried to get TrainerRoad to use the trainer's #'s to set power. That was another fail. TrainerRoad refused to calibrate the Tacx. So then I tried to use the Tacx Android app to run the trainer. The app refused to control it. The app could see it, but no control. Then I tried to get my Wahoo Elmnt to control the Tacx. That didn't work either.

The only thing that worked was using TrainerRoad to put the Tacx Flow Smart into Resistance mode like a dumb $100 trainer. What a complete waste of money. And, sadly, since I waited a month to actually try the darn thing, I probably can't send it back. No more smart trainers for me.

"If only he had used his genius for niceness, instead of Evil." M. Smart
Quote Reply