At one point, Professor Tree reserved a bicycle full of weed in the Celadon Mall.
As Rusty arrives on the bicycle shop, he tells that the cashier that he'll pick the red bicycle, which costs a million dollars, which had made Rusty believes that this was a Legendary bike, and the cashier says that this was a "one-of-a-kind" bike. As the cashier says that this was reserved for a "very special person". Rusty believes that he was that special customer, and purchases the bike with his father's credit cards (as opposed for using a Bike Voucher).
As Rusty rode his bicycle in a mall, Prof. Tree screamed that he shouldn't use the bike, and tells him that this shop has a Cinnabon. Rusty told Prof. Tree that he can't stay and talk so he can rescue Pikachu while still riding his bicycle in the mall. Prof. Tree later told the cashier that he was supposed to buy the bicycle that he reserved, and he told the professor that he sold it to Rusty.
Rusty used the bike to chase Team Rocket after having a conversation with Julian.
The Newest Member of Team RocketEdit
As Rusty failed to fool Team Rocket for saving Pikachu, one of the members pointed out his bike being full of weed, which the members welcomed him as a member. Rusty also left the bike at the HQ afterwards.
In the altered timeline caused by Future Rusty, the bike was probably never purchased by Rusty due to not stealing his father's credit cards.