Any juddering symptoms experienced while using the kit are usually related to an issue within the controller. In order to help our technical team determine how best to fix this issue, you can carry out the below test:
1 - Disconnect the power pack from the bike.
2 - Spin the wheel backwards, taking particular note of any resistance or noise. (Please see attached video for guidance)
3 - Repeat this with the power pack connected to the bracket.
If you notice any excessive resistance/noise coming from the motor or any difference with the power pack connected to the bracket, please open a support ticket - preferably with a video showing this resistance if you are able.
It is also worth checking whether easing off on the pedals temporarily halts the judder symptoms - particularly if you did not notice any excessive resistance in the previous test. In both cases, a replacement Powerpack controller is often the fix here following a chat with one of our engineers.