Saddelrörsvinkel

Saddelrörsvinkel, often referred to as seat tube angle in English, is a fundamental geometry measurement in bicycle design. It describes the angle between the seat tube of the bicycle frame and a horizontal line. This angle plays a significant role in how a rider is positioned on the bike and consequently affects pedaling efficiency, comfort, and handling characteristics.

A steeper seat tube angle, meaning the seat tube is more vertical, typically places the rider further forward relative to the bottom bracket. This position can be advantageous for climbing and aggressive riding, as it allows for more direct power transfer and a more aerodynamic stance. It can also lead to a more forward-leaning posture.

Conversely, a slacker seat tube angle, where the seat tube is more reclined, positions the rider further back over the rear wheel. This geometry is often found on mountain bikes designed for descending and rough terrain, as it can improve stability and control when going downhill. It can also offer a more relaxed and upright riding position for endurance or touring.

The saddle height and fore-aft position also interact with the seat tube angle to determine the rider's precise position. However, the seat tube angle itself is a primary determinant of the rider's weight distribution over the wheels and their biomechanical relationship to the pedals. Different riding disciplines and rider preferences will favor different seat tube angles.