This is a great bike, and our 4 year old son loves it. Assembly is super simple, attached the seat, the pedals, the front wheel, the handle bars, and the training wheels. Assembly takes all of about 15 minutes. The only reason I gave this bike 4 stars instead of 5 is that the plates over the spokes makes it difficult to pump up the tires. There is very limited room to access the Valve stem. I recommend taking the tires off the bike, removing the plates over the spokes, pumping the tires, then reassembling. Also if you have limited garage space, the plates over the spokes prevent you from using the normal bike hooks to hang the bike from the garage ceiling.