Tacx Fortius parameters (power, cadence, speed) freezing during workout

[pim555]

Hi all,

I recently discovered GC as an alternative to my really old TTS on my Taxc Fortius (head unit model 1932). Am amazed by the amount of features you guys have build into this tool!

After some struggles in setting it up (running on a clean Windows 10 x64 machine, had to manually install the libusb drivers and certificate) I managed to get everything working...I thought.

GC starts fine, I can go into train mode and select a workout. The workout seems to control the resistance of the trainer and I get visual feedback on power delivered, cadence and speed. However, after an arbitrary number of minutes, the Tacx parameters (power, speed, cadence) stop updating. I can feel that resistance is still being controlled but values are not updated in GC anymore. So it seems like the connection to the Tacx is still present and GC is controlling it's resistance but GC is not reading values anymore.

I tried changing USB ports, disabling virus protector, etc. but no luck. The only way to resolve seems to be to stop GC, power off on Tacx and power back on again. Then start GC again...

Any clues what is going on?

Btw, unplugging the head unit during a training session shows the "connection failed" message but I cannot get rid of that anymore when plugging back in. Have to stop the GC application via task manager for that.

Best

Pim

[Evan Walpole]

I too have a Fortius Multiplayer (T1932 head unit, T1941 motor brake), and use it regularly with GoldenCheetah on Windows 10 x64.

This may help:

1) Disable Windows USB power management. Start —> Settings —> System —> Power and Sleep —> Additional Power Settings —> Change Plan Settings —> Change Advanced Power Settings —> USB Settings —> USB selective suspend setting —> Setting: Disabled.

2) Check the Power Back / Motor Break lead wires are properly secured:

http://www.mediafire.com/file/h21nonzdnj2/information%20cable%20check%20T1941.50.pdf

3) Check head unit cable connections. The USB Type B female connector on the T1932 is fragile and the vibrations from trainer use can often dislodge the male USB lead momentarily. Generally I would refrain from removing the USB lead from the head unit altogether, as it appears the connection was not designed for more than a few hundred insertions. Permanently mount the head unit from the handlebar to the bottom of the trainer frame. 

Even with all those fixes, expect about 1 in 10 training sessions in GC to crash with Fortius. If this happens your train session data will not be saved, and the program will need to be killed via Task Manager. You should also know that the power output numbers are wildly inaccurate. In my case, the GC calculated Fortius Power Output is ~2x what my PowerTap hub shows. 

If you don't own a power meter, and want accurate power numbers (within ~5%), I would suggest installing a 32-bit version of Windows on a Virtual Machine and use the old free Fortius Software which can be found here:

http://www.lunicus.org/tacx/Fortius.htm

Alternatively if you have two spare ANT+ USB sticks lying around, you could also try a version of the Antifier project as mentioned here: https://support.zwift.com/hc/en-us/community/posts/203861465-Support-for-Tacx-older-smart-trainers?page=7#comments

Hope that helps.

[pim555]

Thanks Evan,

I will definitely try disabling USB power management.

The other suggestions make sense as well but my set-up is working with the free TTS software you refer to below so I assume that hardware connections are ok.

Power numbers do not seem to be that much off. I dont have a power meter but from the sessions I have done so far, the power numbers displayed seem to be higher than what I am outputting (or my power output has gone through the roof recently which I dont expect:-)) but I dont think it is 2x as high. Probably more in order of 20-30% higher.

The antifier is next on my list to see if I can get that working on a raspberry PI and connect to a PC running Zwift.

Best

Pim

[Evan Walpole]

My ANT+ Powertap vs GC modelled Tacx Fortius (T1932 head unit, T1941 motor, 220v Power Back):
https://15413409396008878136.googlegroups.com/attach/955dd0565475e/Picture1.png?part=0.1&view=1&vt=ANaJVrGjgpRfTOH9MnVuXa6TKp6LeGgPSS-W-knxRoBfFs-s-XnpV4imom23ILk8_MehJYp-tunXNiVE4htz95myqBRCI3IiKQi_WNxYLR0AQ7C0r58WNPA

You can use Antifier on the same PC running Zwift! However Antifier was coded in-mind for the wired eddy-current resistance unit Tacx trainers (iFlow, iMagic, etc). Fortius support is kinda flakey - iffy power numbers and the erg mode is prone to wind-up locking. But slope mode works just fine in Zwift, Road Grand Tours et al. It's an ideal solution if you also have a power meter installed on your bicycle. 

[pim555]

Seems like disabling USB power management is improving stability but will need to further test this.

if you run antifier on the same PC, would you need to ANT+ dongles in that same PC? 

[pim555]

Unfortunately it still doesn't work reliably. GC parameters are still freezing up after a few minutes of riding.

Best
Pim