At a height of 5'4" or 163 cm, the Triumph Street Twin could be a suitable option for you. The Street Twin has a relatively low seat height, which makes it more accessible for riders with shorter inseams. However, it's important to keep in mind that personal comfort can vary based on factors such as leg length, torso height, and riding preferences.
If possible, it's highly recommended to visit a local Triumph dealership or a motorcycle rental service to sit on the bike and take it for a test ride. This will give you a better sense of how comfortable you feel on the Street Twin and whether it accommodates your height and riding style.
Additionally, adjusting the suspension settings and potentially using a lower seat option or adjusting the existing seat can help fine-tune the ergonomics of the motorcycle to suit your needs. Motorcycle gear like boots with thicker soles can also help you reach the ground more comfortably.
Remember, rider comfort and confidence are crucial for a safe and enjoyable riding experience. Taking the time to try out the bike and explore various options will help you make an informed decision that suits your individual requirements.