The first TR any Watt Trader offers always is between TR00 and TR49 (inclusive), and increases each day (where TR49 becomes TR00), if the game was saved the day before. Within that domain, each Watt Trader's first TR is seven more than the last one's, in the order shown above; e.g., if the Watt Trader at Meetup Spot offers TR00, the one at East Lake Axewell offers TR07, etc.
Any Watt Trader's stock solely depends on the first TR he offers, in the following way:
The second TR is 24 more than the first
The third TR is 42 more than the first
The fourth TR is 67 more than the first (or, if that would result in 100 or more, 100 less than that)
The fifth TR is 96 more than the first (or, if that would result in 100 or more, 100 less than that)
The Rotom Rally is a competition that requires the player to ride the Rotom Bike and reach the location of another Watt Trader in within a predefined amount of time. The destination can be any Watt Trader the player has previously visited.
During the Rotom Rally, when the player passes through a white balloon, the Rotom Bike receives a temporary speed boost. When passing through a red balloon, there is a time bonification and the road ahead (if any) will be populated with balloons. Contacting wild Pokémon does not trigger a battle but instead causes the bike to spin to a stop, costing the player speed.
After successfully completing the Rotom Rally, the attempt is graded with a score, and the player receives some Watts. For their first successful attempt, the player receives TM14 (Thunder Wave) from the Watt Trader. The eleventh successful attempt will earn the player a Fast Ball. The first attempt with more than 20,000 points is rewarded with TM80 (Volt Switch).
Outfit color change
Watt Traders will offer to change the color of the Rotom Bike outfit free of charge. He will offer colors that match the type or types of the first Pokémon in the player's party, as well as Rotom colors.
Rotom Bike upgrade
Watt Traders will offer to improve the Rotom Bike by boosting its turbo-boost charge speed. They can improve the bike up to three times; they will charge 1,000W for the first upgrade, 3,000W for the second, and 5,000W for the third.