# Trouble shooting calibrating and what happen to wrench icon **URL:** \ **Category:** General Discussion\ **Created:** [February 15, 2023, 2:50pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354 "2023-02-15T14:50:44Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Gaming\_First\_Respond](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/gaming_first_respond/32/448055_2.png) [@Gaming\_First\_Respond](https://forums.zwift.com/u/Gaming_First_Respond)\ **Post date:** [February 15, 2023, 2:50pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/1 "2023-02-15T14:50:44Z")
Why can’t I calibrate my Zwift and happened to the wrench icon that allows you to calibrate at the beginning when u turn on the Zwift app using the an I phone 10 and updated However I did change my bike chain, and replaced both jockeys and rear derailed cable but why can’t I calibrate my wahoo kicker ---
**Author:** ![James\_Zwift](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/james_zwift/32/467851_2.png) [@James\_Zwift](https://forums.zwift.com/u/James_Zwift)\ **Post date:** [February 15, 2023, 2:51pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/2 "2023-02-15T14:51:33Z")
Use your Wahoo app to calibrate your trainer - it will be more accurate as the manufacturer designed it. ---
**Author:** ![Chris\_Holton](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/chris_holton/32/506684_2.png) [@Chris\_Holton](https://forums.zwift.com/u/Chris_Holton)\ **Post date:** [February 15, 2023, 3:30pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/3 "2023-02-15T15:30:43Z")
the advice is always “use the manufactures app to calibrate your trainer” so why is the option even there in zwift? especially if it is known to be inaccurate ---
**Author:** ![James\_Zwift](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/james_zwift/32/467851_2.png) [@James\_Zwift](https://forums.zwift.com/u/James_Zwift)\ **Post date:** [February 15, 2023, 3:36pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/4 "2023-02-15T15:36:23Z")
Because it’s a.one size fits all solution. ---
**Author:** ![Chris\_Holton](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/chris_holton/32/506684_2.png) [@Chris\_Holton](https://forums.zwift.com/u/Chris_Holton)\ **Post date:** [February 15, 2023, 3:44pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/5 "2023-02-15T15:44:06Z")
not sure i follow what you mean? ---
**Author:** ![James\_Zwift](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/james_zwift/32/467851_2.png) [@James\_Zwift](https://forums.zwift.com/u/James_Zwift)\ **Post date:** [February 15, 2023, 3:48pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/6 "2023-02-15T15:48:34Z")
It allowed people with various different trainers to check their calibration, versus the actually manufacturer creating a calibration tool specifically for that trainer. ---
**Author:** ![Chris\_Holton](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/chris_holton/32/506684_2.png) [@Chris\_Holton](https://forums.zwift.com/u/Chris_Holton)\ **Post date:** [February 15, 2023, 3:56pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/7 "2023-02-15T15:56:34Z")
it doesn’t check the calibration though, it changes the calibration value, if it is known to wrongly calibrate trainers and it is better not to use it then why is it still there as an option? ---
**Author:** ![Paul\_Southworth](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/paul_southworth/32/538336_2.png) [@Paul\_Southworth](https://forums.zwift.com/u/Paul_Southworth)\ **Post date:** [February 15, 2023, 3:58pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/8 "2023-02-15T15:58:56Z")
I don’t mind that calibration in Zwift exists - sometimes it works when the manufacturer’s app does not. But it should come with a warning telling users to always try the manufacturer’s app first and not to duplicate the calibration in Zwift if it succeeded in the manufacturer’s app. This is a common source of confusion for users, who end up either calibrating twice or not even trying the manufacturer’s app. ---
**Author:** ![Chris\_Holton](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/chris_holton/32/506684_2.png) [@Chris\_Holton](https://forums.zwift.com/u/Chris_Holton)\ **Post date:** [February 15, 2023, 4:02pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/9 "2023-02-15T16:02:34Z")
> [@Paul\_Southworth](#): > > sometimes it works when the manufacturer’s app does not. how do you know it calibrates it correctly though? from what i am understanding from the above it doesn’t calibrate it accurately ---
**Author:** ![Paul\_Southworth](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/paul_southworth/32/538336_2.png) [@Paul\_Southworth](https://forums.zwift.com/u/Paul_Southworth)\ **Post date:** [February 15, 2023, 4:10pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/10 "2023-02-15T16:10:22Z")
Regardless of how it’s calibrated, it’s impossible to know if the trainer is well calibrated without multiple ways to validate power readings. I have no idea how accuracy varies across the different calibration methods. Users who can’t calibrate in the manufacturer’s app should probably contact the manufacturer for support, but I have heard from people who can calibrate in Zwift but not using the manufacturer’s app. It’s probably better than doing nothing, especially for wheel-on smart trainers that will probably be wildly off without calibration. 🤷‍♂️ ---
**Author:** ![Gerrie\_Delport\_ODZ](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/gerrie_delport_odz/32/437556_2.png) [@Gerrie\_Delport\_ODZ](https://forums.zwift.com/u/Gerrie_Delport_ODZ)\ **Post date:** [February 15, 2023, 4:20pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/11 "2023-02-15T16:20:00Z")
I don’t think the issue is inaccurate calibration it is more that the Trainer manufacturer will update the trainer firmware and also the calibration process on the app , so using the manufacturer you are sure to have the latest firmware and calibration parameters for your trainer. Zwift may not get the latest values from the manufacturer in time for a update or not get it until someone ask. ---
**Author:** ![Chris\_Holton](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/chris_holton/32/506684_2.png) [@Chris\_Holton](https://forums.zwift.com/u/Chris_Holton)\ **Post date:** [February 15, 2023, 4:29pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/12 "2023-02-15T16:29:34Z")
> [@Gerrie\_Delport\_ODZ](#): > > I don’t think the issue is inaccurate calibration then i misunderstood this > [@James\_Zwift](#): > > it will be more accurate as the manufacturer designed it. > [@Gerrie\_Delport\_ODZ](#): > > Zwift may not get the latest values from the manufacturer in time for a update or not get it until someone ask. what happens in this case? won’t that mean that the calibration values that zwift sets the trainer at will be wrong? and so the power values won’t be correct? or will it just not work? are we to assume that if zwift says “success” it has calibrated correctly or not? ---
**Author:** ![Paul\_Southworth](https://sea2.discourse-cdn.com/gozwift/user_avatar/forums.zwift.com/paul_southworth/32/538336_2.png) [@Paul\_Southworth](https://forums.zwift.com/u/Paul_Southworth)\ **Post date:** [February 15, 2023, 4:44pm UTC](https://forums.zwift.com/t/trouble-shooting-calibrating-and-what-happen-to-wrench-icon/602354/13 "2023-02-15T16:44:27Z")
Zwift also offers calibration for trainers that are not supported for calibration in Zwift. The list of supported trainers is pretty small. I imagine that means calibration is offered even if no testing has been done to discover whether it really works properly.