The optimum height for a rider on a motorcycle like the Triumph Bonneville T100 can vary depending on personal preference and riding style. However, as a general guideline, riders with a height ranging from 5 feet 6 inches (167 cm) to 6 feet (183 cm) tend to find the Bonneville T100 comfortable.
The Bonneville T100 has a seat height of approximately 30.5 inches (77.5 cm), which allows most riders with an average height to comfortably reach the ground when seated. However, it's important to note that motorcycle fit is not solely determined by height but also by leg length, torso length, and personal preferences for riding posture.
Ultimately, the best way to determine if the Triumph Bonneville T100 is suitable for you is to visit a dealership and sit on the bike to gauge your comfort level. Additionally, taking a test ride can provide valuable insight into how the motorcycle handles and feels for your specific height and body type.