Calibration ruining everything!!

(P Rui) #21

I had experienced the same with my tacx vortex, last week I unfortunately made a calibration from the zwift option tool, and the nightmare arrived. Since that I couldn´t anymore put watts as I had made before, I lost all my references and I burn my legs with a easy workout!!!
I only could fix the problem, more on less with the calibration from the “tacx utility tool”.I have more friends with the same problem and with other trainers like “Elite”, I think, it’s a Zwift problem and it’s relationed with your option to calibrate. Zwift need to do something!!

(Jeff Ludwikoski *USMES* EVR (D)) #22

Purchased my Magnus from Zwift as part of their bundle package. Worked fine for a few hours until I made the error of attempting the calibration.  Is there anyway I can reset to the way was working out of the box?  

(Nigel ) #23

Jeff. Download the free Rouvy app from Cycleops. Do a spindown using that. You’ll find it under “Free ride”. You’ll need to create a free account. You might also find once you’ve loaded up Rouvy and paired your Magnus that there’s a firmware update. Install that if there is one. It will tell you if there’s an update.

(Robert Jensen) #24

We have two Ipads at the house, one with an older software and one with a fresh download Zwift app.

The old app with no calibration feature paired with the Cyclops Hammer has always been a consistent  2-5%  off of our SRM’s which is fine.

Last night I installed the latest version of the app with the calibration feature and the trainer would offer only 100 watts.  after multiple attempts I simply could not get it to work.  Always get’s stuck at 2mph.

Please fix this!

(Eric Oleson [VISION] CVR B) #25

My Cycleops Hammer always fails the spindown test at 2mph on Zwift and of course Cycleops was no help and told me I would need ANOTHER power meter to test it? Has anyone been successful using the Hammer and Zwift for a calibration?


(Nigel ) #26

Only use the free Rouvy app to do a spindown with Cycleops smart trainers. Refer the following knowledge base article:

(Martin Matejsek) #27

I’m having trouble with calibration on my magnus also and honestly not sure I can trust either zwift or the rouvy app. Zwift has a few times completed the calibration for me but only maybe one in 10 attempts. Also I noticed even if it fails to conplete it will still alter the calibration. Almost like it does do it yet it never says complete. The rouvy app calibration seems to produce upwards of 50Watts difference. In other words 130W using the rouvy app feels like 180-190W zwift calibration. I also noticed that using the rouvy app the calibration will change rather dramatically from cold to 10minutes of warm up to 30 minutes of warm up so in order to be accurate you would need to calibrate more than once in a ride. Infortunately once you start a Zwift ride it takes over the trainer and you can’t do a second calibration in Rouvy.

In the end I feel like Zwift is not compatible with Cycleops trainers. This calibration problem is a huge bummer. It should be #1 priority. I really like my zwift but without accuracy within 50W how are you supposed to train properly when 10W is a big deal for FTP.

(Martin Matejsek) #28

One more thing I noticed is once a calibration fails it locks up the ERG or smart functionality. Unplugging the magnus, ending the ride and starting back over is usually needed to reset the trainer back to ERG. This is yet another reason you can’t calibrate in zwift during a ride.

I think the only way to know what is accurate would be to buy a power meter but then you would lose ERG controllable. I wish I new these problems before picking Cyleops for my smart trainer. To make matters worse I bought two. Now wishing I went with Kinetics or Tac.

(Nigel ) #29

“Infortunately once you start a Zwift ride it takes over the trainer and you can’t do a second calibration in Rouvy.”

Sure you can. Stop your ride. Press the A key to get to the pairing screen. Unpair your trainer. Do the spindown using the 3rd party app, Rouvy in this case. Shut Rouvy down then pair your trainer. That’s how I do a spindown on my Cycleops Hammer trainer.

With training it’s consistency in power readings you’re after. The Magnus is rated at +/- 5% accuracy. So long as you do a spindown after warming it up you should get consistent readings from day to day. If you want better accuracy then you need a direct drive trainer, better still a direct drive trainer and a power meter. I find the Hammer is within +/- 3% tolerance Cycleops claims compared to my power meter.

If you believe your Magnus is 50 watts out then you should either take it back for a refund (as I did with a Kickr Snap) or file a support ticket with Cycleops.

If you have a power meter and a smart trainer you don’t lose the trainer being ERG controllable. You have the option of using the power readings from either the trainer or the power meter. If you use the power meter’s power this is used to adjust the resistance of the smart trainer. That’s how I use my Hammer in ERG mode for training. The Magnus is just the same.

(Martin Matejsek) #30

Thanks Nigel, very helpful. I bought two magnus trainers one for myself and one for my girlfried and we both have experienced problems with Zwift’s calibration. The other day she tried to recalibrate and it failed to complete then she was getting really high wattage reading. She rode hard and at the end of her ride Zwift noted she had a FTP increase from 256w to 325W! She just increased from 240 to 256W a week ago so I know it was a bad calibration. I ran both of our trainers through the Rouvy calibration and she said she was having a hard time producing 100W, failed her workout yesterday and just gave up. That was hard to take considering she was doing so well up to that point.

I don’t think it is a cycleops problem as both of our magnus trainers seem to have the same or similar problem with Zwift. I’m just not sure wirhout a power meter which calibration to trust. Rouvy seems to produce an overly difficult wattage where Zwift is probably too easy. I suspect the Rouvy calibration may be more accurate or is allt least more consistent, but I see roll downs that vary feom 3.74s to 4.5s from cold to hot so I think it is pretty important to calibrate regularly and it is a real pain doing so outside of Zwift while on a zwift ride.

I think a power meter may be a solution that would avoid all of the warm up change problems and improve accuracy but I expect Zwift calibration tools to work as well. I do think I get decent consistency if I just leave it alone but it bothers me not nowing if the wattage produced is accurate or I’m working out and my FTP numbers are all off from bad Zwift calibration.

Will consider a power meter in the future.

(Olaf Kowalik) #31

I got an email from Zwift saying “don’t forget to calibrate your trainer!” last week so that’s what I did (I have a wheel-on Wahoo KICKR SNAP). Here’s what I learned:

  1. You have to calibrate every. single. ride. I calibrated via the Wahoo iOS app when I got the unit and assumed the calibration was a persistent setting. Having gone through the process a few times it now makes sense that your tire pressure and (with a wheel-on smart trainer) the number of times you turn the tensioning knob will affect your power on each ride.

  2. Calibration made a gigantic difference for me. I thought that calibration was a fine-tuning process which would adjust your power by 10% or so. Not the case with me. My power dropped by nearly 50% after calibration (estimated FTP went from 220 to around 120; PRs were almost double previous; average watts on my ride went from 180 to around 100). I saw a couple comments above where people had a hard time holding 100 watts after calibration–that is certainly true for me now.

3. I don’t know which numbers are right. Since I don’t have a power meter on my bike, I don’t know my actual power in real life; therefore, I don’t know which set of numbers to trust (pre- or post-calibration). Post calibration feels more accurate (just comparing my average speed in Zwift with my average speed in the real world), but I don’t have a real-world measure for comparison.

4. What to do about previous Zwift data? I have been on Zwift only for two months, but the calibration, if accurate, has completely invalidated all my prior data (i.e., I am not going to double my FTP, average watts or PRs any time soon). So I can’t use the previous data as a baseline to measure progress and improvement. I’m going to contact Zwift support to see if they can reset my account back to zero so I can start riding at my new, and sadly much, much lower power.

(T he Rock 58yoL32) #32

had the same problem as started in this thread… at the end I believe all is ok now and here is what I did:

  1. Made sure the Cycleops hammer Firmware was up to date. Loaded Powertap to my smartphone. Made sure the trainer was awake… Opened powertap and selected Update firmward from the menu… It now shows no update needed.,.31.036(27.031) which is the latest according to cycleops.

  2. Loaded Rouvy to my computer (same one that Zwift is on ). Now this is a COLD calibration but it got things close to being right but read on… So In rouvy go to settings and make sure you have cycleops hammer selected and all your sensors- connected…  go to Free Ride.  On the top right corner it shows Calibrate trainer… Mine showed ride to 20-25 MPH… Once I got there I could feel Rouvy controling the trainer, it got real easy to maintain 25 mph-- almost no pressure on pedals… Then it said stop pedalling… It never stopped spinning totally but it came back and said calibration succesful and spin down time was like 19.8 seconds…

3 I then went to Zwift (DO NOT CALIBRATE IN ZWIFT)-- you just calibrated your trainer in rouvy… So I rode around in Zwift for about 20 minutes… The control on the trainer was not back to something normal… HOWEVER i wanted to make a hot calibration… So after 20 minutes of riding in Zwift I closed it up… Went back to my Rouvy app on the PC.-- Went back to step2 above and calibrated again in Rouvy but this time the trainer was warmed up… This time it did the spindown in 21.9 seconds and was successful again…  back to Zwift I go and it feels quite good now… I can not say exactly how accurate the power is now, but for all practicle purposes I think the trainer is working again.!!! yeh!!! 

(Martin Matejsek) #33

Thanks T Rock for the PowerTap firmware update pointer. Both of our magnus trainer firmwares needed updating. The update noted that it adds cadence sensing which it did! I already bout wahoo cadence but the magnus now also does cadence nicely. In addition the magnus firmware noted improved roll down calibration. Upon updating the firmware both trainers were able to get one Zwift calibration to succeed but only the first time. I’m not sure it is right or better than rouvy but it got both of our trainers back to the calibration we were used and per what our FTP was set so we are back to normal and happy. I’m a little affraid to try Rouvy calibration again and just going to leave them as is for a while unless something feels wrong.

Hopefully the next firmwarw or Zwift update will polish off the last of the cycleops bug. For now I am sticking with Zwift calibration after firwarw update feom powertap and just leaving it alone.

(T he Rock 58yoL32) #34

Today is  Dec 21… Been about 11 days since I calibrated my cycleops  Hammer in Rouvy (Again do NOT calibrate it in Zwift-- calibration does not work for the hammer in Zwift). Seems all continues to run fine… The only problem I still see is CYCLEOPS  still has a SW bug.,. I saw this when I first got my trainer and had not updated the SW… When there is a steep change in incline-- for example going down and hill and then a hard transition up a hill, originally the hammer would just go to ZERO. I would be standing on the pedals putting out 500 watts , but ZERO MPH. My avatar would stop just after the transition going uphill and unclip , and then get going again after a second or two. Then I made the SW update to the Hammer with the POWERTAP APP on my Iphone… So Updated to that Sept release… Now I never just stop to 0 MPH… But I can still see people blow past me when I hit these changes in elevation- going from downhill to uphill.   SO I still  stand on the pedals, put out 500 watts., and  the system just slows me down a little, so every body still passes me but at least I dont stop any longer… Probably just lose a little speed and then it comes back after a few seconds…  Quite annoying if one is trying to race…but at least it does not go to ZERO MPH any longer… I hope they- Cycleops / Saris etc fix this bug soon…

(T he Rock 58yoL32) #35

Dec 23— Just saw Cycleops  released a new update for the Hammer Smart trainer… Just used Powertap Iphone app and made the update to 31.040 Dec 19 release… It says it made this zero power  and power dropouts better.  I hope this works… Will ride 40 miles today in Zwift and see what happens!!!    Fingers and toes crossed!!!

(Tim McCarthy) #36

i was having the same trouble with zwift with my new magnus.  it seems rebooting the apple pro may have been the key move, AFTER the magnus firmware update. 



(Tim McCarthy) #37

thanks Trock T rex 


(Martin Matejsek) #38

Thanks T Rock, I checked powertap and see there is another magnus firmware update available as well that notes the same dropout improvment.

I’m sticking with my set it and forget it routine for now though. I have a trainer tire on and check my pressure at 140psi, I also do not remove the bike from the trainer so my tension knob setting is a constant. I’ve been doing a lot of SST workouts and feel my FTP climbing so I don’t want to mess with the calibration. I’m still thinking a power meter is the way to go to avoid the calibration issues.

(Brian PDX Kruse) #39

So like in the real world when a vulnerability gets exposed, the hole gets plugged.

With this calibration problem on my Magnus I was able to unlock the 1000 watt achievement with about 200 watts of real effort (my guess).

Here’s what I did:

  • Entered workout mode for “The Gorby” in ERG mode.
  • During the warm up around 9 minutes I decided "hey this would be good to calibrate this new trainer of mine and it said to do it after a warm up period.
  • I clicked “Menu”
  • Clicked “Pair devices”
  • Clicked the little wrench next to the power meter that’s paired

Now it says “Pedal to 23 mph”.  So I begin but it fails, stopping at about 4 mph.

I figure maybe I have the tension knob too tight, so I loosen it a half turn.  

I start the wrench thing again and while I’m pedaling toward 20, I get an “Achievement” unlock…600 watts.  Hmmm

The spin down stops at 2 mph.  I figure I’m onto something.  I loosen the knob another 1/2 turn.

 Wrench thing, 700 watts unlocked, spin down to 1 mph.  Whew I figure, almost there. Loosen 1/2 turn.

Wrench thing, speed up 1000 watts unlocked. Spindown to 1 mph.  Shrug, oh well this isn’t working.  Back to the work out.

Cadence now 70ish and no effort…300 watts!!  Uh oh.  This ain’t right.  Unplug and reboot everything.  Still no effect.

I read about needing to recal with Rouvy.  I do that.  Back to normal…well almost normal.  Now I realize that I had out of the box about 25% too low of power readings!! No wonder I’m last in D!!  

Zwift:  You’re going to have guys with correct weight and heart rates within spec (cuz they’re doing push ups on their bars) and they’re crushing 6.0 for an hour.

Good news for me though, recalibrating is going to keep me in front of some folks.  All this work thinking I’m at a plateau is going to really pay off now!!  Cheers.

(Nigel ) #40

Problem is most of the guys with miscalibrated trainers don’t know they’re miscalibrated. They just assume because they’re reasonably fit that the 350 - 400 watts they can hold for an hour is correct since they have nothing to compare to.

Anyway glad you’ve got things sorted.