"Darby's Wheelie Big Problem" is the first segment of the forty-first episode of My Friends Tigger & Pooh.
Following a particularly messy case, the Super Sleuths find that their scooters need a good cleaning. With the scooters out of commission for the time being, Pooh and Tigger substitute bicycles. Both are very fast on them, but Darby's still using training wheels. She'd like to be able to go as fast as the others, but is scared that she's going to fall.