Trainer reaction time

Hi, this is my first post and I am new to Trainerroad. I have looked through the forum to try and find an answer to my problem but I can’t find one that answers my problem. I have sent an email to support in which their reply was they are really busy at the moment so I thought I might try on here also, I hope that’s OK.
I have just signed up for trainerroad and installed the app on my Android phone and desktop Windows PC. I have the Tacx Ironman trainer.

I can get my phone to control the trainer really well and pretty much following target wattage perfectly. Unfortunately the same cannot be said when trying from my pc. The order of events as follows,

Installed Trainerroad on computer.
Paired power meter, heartrate and tacx.
Loaded a workout, it worked but it seemed to take an age for the trainer to adjust resistance to target wattage. Large swings of power above and below target wattage.
Calibrated tacx with tacx utility and made sure it’s firmware was up to date.
Googled my problem and found I should have preformed a Trainerroad spindown calibration
Tried but it kept failing/timing out.
Googled and found I could try altering my trainer resistance pressure.
This didn’t work and thought I had a problem with my trainer.
Loaded trainerroad app onto my Samsung galaxy.
Performed spindown calibration via the phone and it works. I made sure the trainer was being controlled on ANT+ just like my pc.
Tried to perform a spindown calibration again on the pc and this time it worked.
Tried a workout and I could hardly spin the cranks and my wattage was sky high, the trainer took forever to lower the wattage and I couldn’t sustain the workout.
Tried to re-calibrate but I keep getting calibration successful even though I haven’t even pedalled, or failed calibration timeout.
Uninstalled Trainerroad pc.
Installed Ant+ usb and Trainerroad again.
Trainerroad still remembers the spin down calibration from before and fails everytime I try to recalibrate.
Restarted pc but still the same.
Tried Trainerroad again from my phone and it works perfectly.
I tried forgetting trainer device on pc and trying again after they were paired but still no joy.
I have a usb ext cable so my ant+ dongle is just above my crank, in my mind close enough to my trainer.
I have unplugged my sonos wireless wireless speaker.
Tried again and with no joy.
I uninstalled trainerroad and the usb drivers again and then reinstalled.
trainerroad still remembers the last spindown calibration and the first time I try a recalibration after reinstalling trainerroad immediately comes up with successful calibration dialog box before I’ve even pedalled.
Again tried Trainerroad from my phone and it works great.

I cannot think of anything else to try. I would like to start again but a normal pc uninstall doesn’t seem to wipe away everything as trainerroad remembers the last spindown calibration. Is there any way to accomplish this? Any other suggestions?

Please help,

many thanks in advance,


This may sound dumb, perhaps worth trying different port/pc, just to eliminate this as a possibility…

Also, the primary software, say TR, must have an exclusive access to the trainer to control it correctly, worth checking that it is not paired or controlled via another software, say phone app. This is possible because there are 2 channels to communicate with the trainer, via ANT+ or/and BT, perhaps ANT+ allows multiple pairing as well…

Check this ^. Turn off your phone just to be sure, then try your PC again. If your PC still doesn’t work, just use your phone.
I run TR from my phone, and it works great. Easy to mount the phone on your bars for access to pause, +/-, etc.

Hi @nordic , I had already tried swapping the Ant+ dongle to a different port but I forgot to mention that part ,Sorry. I will try with phone switched off.

Today my bled112 arrived and I tried controlling my trainer through that. In devices I forgot the ant+ trainer and paired the bluetooth version. A dialog box came up recommending a spindown calibration. It failed every attempt.
I tried a workout and it let me ride but like my very 1st ride the trainer response was very up and down, above and below target wattage. I reversed what I had just done and when I tried again on ant+ it was again nearly impossible to turn the cranks.
Ahaa I thought, I again reversed the process and sure enough I could ride again with power above and below target wattage. Also spindown calibration failed. This time I had saved the workout so I could show my fluctuations. I then closed down TR but the computer was still on. I collected my phone from downstairs so I could have another go with the phone.
I then tried via my phone and TR said do you want to continue workout? Perfect now I can compare. Unfortunately this time the phone control seems to fluctuate just like my pc. As I didn’t save anything yesterday I cannot compare but I’m confident yesterday the phone controlled the trainer perfectly.
So to some up, I can now ride via my phone and pc on bluetooth with the fluctuations/slow trainer response speeds.
I cannot perform spindown calibrations on my pc with Ant+ or bluetooth. I haven’t tried again on my phone and didn’t before this last test. Maybe that’s why the phone didn’t control like last time. I’ll have to go and try again.

All this leads me to other questions. I want my power graph to be like a friends, he uses a whahoo kickr. His power lines follows target power perfectly.
1/ Can wheel on trainers like my tacx ironman do that and therefore I was mistaken in what I thought my phone control was like.
2/What wattage drift is acceptable above and below target wattage?

Thanks again,

I have just tried to calibrate again with just my phone. I tried ant+ and bluetooth, this time it failed every calibration.
The successful calibration on my phone yesterday had an offset of 43 whilst the pc offset was something like 65, I don’t know if this means anything.
Maybe I do have a trainer problem. Does anyone else have a tacx Ironman running on TR?


I have a tacx igenius wheel on trainer that originally wasn’t “smart” until I purchased the add on a few years ago. I think your trainer is essentially a rebranded igenius ??

I run the trainer via Bluetooth to the iOS trainerroad app exclusively.

Make sure the trainer isn’t connected in your phones Bluetooth connections.

I would install the tacx utility on your phone and check the firmware on the trainer is up to date. Then pump up the tyre and note the psi down as this will be your go to pressure in the future. Then calibrate the trainer in the tacx utility and again make a note of where your line is set after adjusting as necessary and make a note when happy. Shutdown the tacx utility.

Run trainerroad and connect to the trainer and do the spindown in there. I have had issues at this point myself. Sometimes have to be carefully not to apply too much pedal force to get the spin down started. Sometimes if it keeps failing I power cycle the trainer. I think my spindown is about 6s normally in trainerroad.

Even when I have had issues with the trainerroad spindown so long as the tacx calibration was ok trainerroad has been fine and responsive in erg mode (I never use resistance).

I’ve never bothered with trainerroad on the PC with ant+ but I have used zwift and TTS in the past and early on I learnt never to have garmin express running as it would interfere with then as it was using the ant+ dongle.

@SeeEl thanks. My trainer firmware is up to date and I had done a calibration with the tacx utility.
I have just tried again after reading Tacx warranty pages. I found out I had been running the alignment tool in the tacx utility wrong, I had left the wheel connected previously. This time I aligned with the wheel off.
I tried a spindown calibration again on my phone with my pc OFF After a couple of attempts it calibrated and when I ran a workout the wattage fluctuated +/- 1-2 watts , which considering the fluctuations of what a power meter gives out anyway, perfect.

I switched the phone off and started my pc. I tried a spindown calibration a few times and eventually got success. I can’t remember whether it was ant+ or bluetooth, oops.
I ran a workout and the wattage fluctuation was slightly worse than the phone, so easily accurate enough for me.

Your point about not starting the spindown with to much force rings a bell. That’s exactly how I have to perform a calibration using the tacx utility.
So hopefully the alignment and an easier spindown start is the way forward. I plan on actually doing a full workout tomorrow so I’ll keep you all posted.

Thanks very much for taking the time to respond.

Well done being persistent to figure this out! Sometimes BLE/ANT connections can be a pain to figure out.

Once you get it right, use a consistent approach each time and things should work in a repeatable way.

Sounds like your issues may have been a mix of incorrect alignment, and multiple devices trying to connect to/control the trainer.

With alignment right, then just make sure only one device (either PC or phone) is running/controlling your trainer. And one way to do this is to turn the other device off.


Here’s my latest workout and you can see the power fluctuations are minor. The power spikes lining up with cadence drops are just me getting out the saddle.

@SeeEl , nice graph.
Earlier today my phone would have been close. I tried again on the pc early this evening thinking I had it cracked. Unfortunately I couldn’t get a successful calibration either ant+ or bluetooth no matter what I tried. My graph doesn’t look that clean.

I’ll try again tomorrow.


You are getting there, it doesn’t look bad. I recall a lot of thrustration myself first few weeks until me and equipment found a way to work together. It’s not perfect, there is always something. It’s more about finding consistency so workouts are done as intended and progress can be observed. Once you are happy with calibration, I would recommend to leave it there, it is not so important to read accurate power, consistency is. If you plan to race on zwift, then perhaps, worth asking someone to lend you an external PM to calibrate trainer occuracy. I think none of trainers have real PMs.

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Nordic makes an excellent point. I ride a Tacx Vortex Smart and my graph looks about the same as yours. I have noted that it often cranks up the resistance initially if it is cold out, and sometimes the TrainerRoad and Zwift battle for control of my ride. It sounds like you are making great progess troubleshooting and while messing up workouts is incredibly frustrating you will reach a balance point where you are satisfied with the quality of the ride and can get it working 97% of the time. When the other 3% pops up, restart everything, have a beer and try again in later.

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@nordic, oops as I thought the spindown calibration was to do with how TR interacts with my trainer, Like a PID loop in instrument control, I didn’t mention that I am running an external PM and have an option (can’t remember it’s name) ticked/on/selected. I thought I had TR adjusting my trainer resistance (Output) depending on what my power meter is reading (Process Variable, actual) compared to the target power (SetPoint)


Cheers @PirateHoy, my ocd just wants a perfect graph but maybe I’ll end up with a compromise of consistency. I appreciate you telling me your graph is similar to mine as I thought everyone had perfect graphs that followed target power.

Hi Simon,

I’m a Customer Support Team Lead at TrainerRoad, and I wanted to follow up with you on your issue. We want to make sure you’re able to perform your calibration and workouts without any issues moving forward. I’m also sorry we came off as too busy in any way — we want to help you get to the bottom of this as soon as possible!

One of our Support Experts, Tucker, followed up with you in your original email request. To try and keep our conversation as organized as possible, I’m hoping you wouldn’t mind if we continue our conversation there.

We’ll look forward to hearing back from you. Also, big thanks to everyone who added their input here!


Hi @nick,
thanks for the follow up. I received an email from Tucker yesterday. It was actually 2 emails with the 1st email dated the day I put my support request in and tagged onto the second email. For some reason I didn’t receive the first email the first time round.
Anyway today I planned to try what Tucker suggested and then report back to him.
Thanks again,

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Stoked to hear you and Tucker have been able to connect to get to the bottom of this!

We’ll do our best to make sure you’re back on the bike without any issues moving forward. :metal: