The fore-aft position of the saddle is actually closely related to the knee joint, yet it is often the most overlooked aspect. Many cyclists or bike shop staff tend to decide the saddle’s position based on aesthetics—such as whether it looks “good” or “cool.” This is quite incorrect. The saddle's fore-aft position, just like saddle height, has a significant impact on the knee joint, so it must be set with care.
Setting the saddle’s fore-aft position is actually quite simple: First, sit properly on the saddle, place the ball of your foot on the pedal in the correct position, and pedal a few times. Then, align the pedals horizontally. At this point, the vertical line dropped from the “lower point of the front knee” should pass directly through the center of the pedal (i.e., the pedal axle). Once that’s achieved, you’re done. If the vertical line does not pass through the center of the pedal, you’ll need to adjust the saddle position accordingly. If the saddle is too far forward or too far back, it can affect leg power output during pedaling and is also closely related to knee wear—so it must be handled with caution.
This position, of course, isn’t set in stone and allows for some flexibility: if you move it slightly further back, it can allow for better and more direct power output from the thighs—ideal for high-power riders who prefer a “big-footed” pedaling style. If you move it slightly forward, it can make the rotation of the knees and calves smoother—suitable for those who favor higher cadence (with less pedaling force but faster pedaling speed). However, regardless of moving it forward or backward, the adjustment should not exceed 2.5 centimeters from the standard position. Going beyond that can easily lead to knee or muscle injuries.
The most common mistake made by average cyclists is placing the saddle too far back. While this might make the bike look sleeker and cooler, and may even give a more solid pedaling feel, the long-term result of such aggressive positioning can actually cause damage to the knees.
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