One common issue parents find with kids is they often rely heavily on training wheels, and of course the training wheels wear out. This is a natural reaction; training wheels have a level of assurance that helps raise confidence. Another way to raise onfidence is by lowering the height of the seat. Initially us parents will think this makes the bike seem too small. That is partially true but the advantages are greater. By lowering the seat the child sits deeper into the wheels and this help lower the medium height for balance. Plus the child will feel safer because they can easily touch the ground, they will feel more secure. Better still, take off the pedals and the trainers and turn the bike into a short term "balance bike", like the ones without pedals (E-200L Balance Learner Bike or E-250L Balance Learner Bike as an example). This way training wheels become only part of the development, not the main thing.