Board Thread:Social and Race Teams Threads/@comment-27109924-20160710043457/@comment-28412524-20160727094224

you can get 1-3 gold on every TimeTrial repeat when you have series exactly on any of completion rewards (25%, 50%, 75%, 100%). You just click reset time trial, hard-reset application (killing it competely) and after restart you will see your completion percetange below the previous percentage. After finishing time trial you will get small reward for recompletion of the progress. Repeat for all series you can and you can get few hundred GCs easily.

BEWARE: when you reset time trial and don't ride it you will be unable to do cloud save (sometimes on app start you will be asked to restore from cloud as progress stored there is bigger than the one on the device)