The provided stem of the CGO600 is fixed. If you would like to raise the handlebar and have another type of riding posture with your CGO600, you can swap the provided stem for an adjustable one. Please kindly select a suitable model, and pay attention not to overly stretch the electric cables or brake tubes. We would highly recommend you complete this modification with the guidance of a professional.If the bike is damaged during the installation of a new adjustable stem, please kindly pardon us for not being able to cover it with the TENWAYS warranty. However, we are still here if you need help, and the rest parts of the warranty will stay intact.