Kickr Core applying brake in workout
Discussion
Evening PH’ers,
Have recently got a new Kickr Core and I love it. Using with Zwift and it’s night and day compared to my dumb trainer. I do, however, have a query when it’s in a workout. I’ve only tried this twice, the first was an FTP test and the second was a Zwift workout event this evening. During both sessions, when being told to put more power on, the brake came on so hard I literally couldn’t turn the wheel. If I stopped trying it free’d up but did it again a few times to the point I bailed and just free rode.
I have googled it but can’t seem any answers so before I go to Wahoo or Zwift support thought I’d see if there were answers here. I’ve done a spin down - twice!
Cheers
Have recently got a new Kickr Core and I love it. Using with Zwift and it’s night and day compared to my dumb trainer. I do, however, have a query when it’s in a workout. I’ve only tried this twice, the first was an FTP test and the second was a Zwift workout event this evening. During both sessions, when being told to put more power on, the brake came on so hard I literally couldn’t turn the wheel. If I stopped trying it free’d up but did it again a few times to the point I bailed and just free rode.
I have googled it but can’t seem any answers so before I go to Wahoo or Zwift support thought I’d see if there were answers here. I’ve done a spin down - twice!
Cheers
Erg mode can be like that depending on how big the step is. You need to start to start spinning up before the step, especially if you are at a low rpm.
If you wait until the change then it can be like hitting a wall, you'll struggle to accelerate, eventually go into a death spiral and grind to a halt.
If you wait until the change then it can be like hitting a wall, you'll struggle to accelerate, eventually go into a death spiral and grind to a halt.
Yes, IIRC it was when going from say 150w to over 300 and I just couldn’t move it. Will try again tomorrow and spin up sooner. Wonder why it does what I’ve experienced as the Zwift instructions are most insistent on keeping to the power until told to change?
Don’t think it’s a pairing type issue although it’s connected to my phone and iPad.
Don’t think it’s a pairing type issue although it’s connected to my phone and iPad.
Yup, I have a Tacx Neo and when going from something like 150 to 300W if you aren't spinning fast at the start of the change you will definitely get into the "death spiral" and end up pushing through treacle. If do you miss a change up in power you can sometimes catch it by pushing very hard and recover. I think it's just to do with the way ERG calculates the resistance needed, they could smooth it out over a longer period, but it would cause a lag the other way.
Edited by Gareth79 on Tuesday 13th October 00:23
If it's purely at a significant power increase then your cadence will typically want to increase. This means you often need to "overshoot" your power target to get to your desired cadence, otherwise you can "bog down".
Try shifting up into an easier gear JUST before the power change. This will keep the flywheel spinning at the same speed but your cadence will increase. When the interval is over, go back into the gear you were in.
Try shifting up into an easier gear JUST before the power change. This will keep the flywheel spinning at the same speed but your cadence will increase. When the interval is over, go back into the gear you were in.
Gareth79 said:
Yup, I have a Tacx Neo and when going from something like 150 to 300W if you aren't spinning fast at the start of the change you will definitely get into the "death spiral" and end up pushing through treacle. If do you miss a change up in power you can sometimes catch it by pushing very hard and recover. I think it's just to do with the way ERG calculates the resistance needed, they could smooth it out over a longer period, but it would cause a lag the other way.
Also get this on Tacx vortex with Zwift. Basically treacle effect kicks in. Most annoying and very very very frustrating.Edited by Gareth79 on Tuesday 13th October 00:23
It takes about 3 seconds for Zwift to communicate the change in wattage to your trainer and for the trainer to shift up or down to that load. As soon as the interval changes, you need to spin up or down to the required cadence as the wattage adjusts. This only happens in ERG mode, too.
If you go from a small wattage to a high wattage and you don't get that cadence increasing fast enough, then the way the trainer calculates the resistance means the slower the flywheel turns, the harder it gets. If you are getting tired and sloppy, you can get into the "spiral of death" where your cadence slows and the resistance increases, further pushing your cadence down and making the resistance go yet higher, normally caused by not getting the cadence right as intervals change.
I found that as my fitness improved, I'd hit the spiral less and less on Zwift workouts, or only on the harder workouts, when I'd been going for longer and I was really starting to run out of gas. Then I'd do an FTP test, which changed my power figures for the intervals, and I'd start struggling much earlier into workouts again. The easiest way to avoid getting stuck in the spiral is to keep the cadence high, but you can't do that all the time, as sometimes the workout will force you to do FTP-15% at 55rpm and then ask for FTP+15% at 95rpm and when you've been going hard for a long time and you're deep into the session on tired legs, those big changes can really catch you out.
If you go from a small wattage to a high wattage and you don't get that cadence increasing fast enough, then the way the trainer calculates the resistance means the slower the flywheel turns, the harder it gets. If you are getting tired and sloppy, you can get into the "spiral of death" where your cadence slows and the resistance increases, further pushing your cadence down and making the resistance go yet higher, normally caused by not getting the cadence right as intervals change.
I found that as my fitness improved, I'd hit the spiral less and less on Zwift workouts, or only on the harder workouts, when I'd been going for longer and I was really starting to run out of gas. Then I'd do an FTP test, which changed my power figures for the intervals, and I'd start struggling much earlier into workouts again. The easiest way to avoid getting stuck in the spiral is to keep the cadence high, but you can't do that all the time, as sometimes the workout will force you to do FTP-15% at 55rpm and then ask for FTP+15% at 95rpm and when you've been going hard for a long time and you're deep into the session on tired legs, those big changes can really catch you out.
This is a good video that explains the "Spiral of Death.
https://www.youtube.com/watch?v=LbeliW8uObk&fb...
https://www.youtube.com/watch?v=LbeliW8uObk&fb...
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