When adjusting a bike at home, the amount of saddle drift is often an overlooked factor, and many people adjust it arbitrarily to bring the handlebars closer or farther away without considering the impact this has on riding and controlling the bike.
1. Saddle drift and perfect balance
In traditional bike adjustments, people usually only follow the principle that "the knee should be in front of the pedal axis". However, the saddle drift has other effects that are not usually considered, and like all bike adjustments, it may determine whether you can ride comfortably for hours instead of making riding a torture.
When adjusting the saddle drift, the first thing to consider is that it will change the rider's position on the bike. This affects the weight distribution between the wheels. Keeping the right balance on this adjustment is crucial to achieving smooth handling of our bikes, especially when going downhill.
If the rear wheel bears too much weight, the front wheel will lose grip, resulting in a strong feeling of insecurity at every turn. On the contrary, if the front wheel is overloaded, although it will enhance the grip of the front wheel, too much load may make it difficult to lean the bike when turning, not to mention that we need to change direction frequently when turning continuously. In addition, if the road surface is dirty or wet, the grip of the rear wheel will also be weakened.
The rearward displacement of the saddle also has an impact on pedaling. If we deviate from the vertical position when applying maximum force, it may cause excessive loading of the meniscus. Excessive rearward displacement also affects the degree of flexion of the hip during each pedaling, causing the leg to be too close to the body. We must consider that when flexion is excessive, the extension force we can generate will be significantly reduced, which will significantly reduce the efficiency at the beginning of each pedaling.
In addition, when we adjust the rearward displacement of the saddle, it will also change the relative position to the handlebars, which may make us overextend or put too much weight on the wrist. Fortunately, this adjustment also has a certain margin of error. In any case, the body itself will try to find the ideal position by moving on the saddle to find the best pedaling posture, although it may cause discomfort.
2. Measurement and adjustment
When adjusting the rearward displacement of the saddle, we must consider several parameters. The first and most important thing is to measure the amount of saddle setback. Traditionally, this is usually done by dropping a plumb line from the front of the saddle and measuring the horizontal distance to the pedal axle. However, modern saddle designs often feature short noses, which changes our reference points.
Obviously, there is no substitute for fitting when it comes to making precise adjustments, but we are still faced with the problem of how to measure this parameter so that we can transfer it from the measuring device to the bike. Although there are many standards, for most saddles on the market, a generally effective and acceptable method is to mark the midpoint of the saddle and use this as a reference point, which, incidentally, must also be used when adjusting the saddle height.
When measuring, we still use the regular plumb line method, but we must be careful to ensure that the plumb line does not touch any part of the bike to avoid affecting the measurement. If we have a laser level, then things are much simpler and it is easier to get accurate measurements.
To facilitate further adjustments in the future, a good method is to mark the position on the saddle rail with a bit of tape, so that if the saddle moves or we make other modifications, we have a clear reference to the amount of change.
When adjusting the setback of the saddle, don't forget that this adjustment affects the height of the saddle relative to the pedal axis, because the adjustment is made along a straight line rather than an arc. Therefore, once the saddle is adjusted, if we move it forward, we may need to raise the height by a few millimeters; if the adjustment is to increase the setback, we may need to lower the height.
3. How to judge whether the setback position of the saddle is properly adjusted
We once again mention the effectiveness of biomechanical analysis, which can ensure that all our measurements on the bicycle, including the setback position of the saddle, are appropriate. However, at home, we can start to check from several aspects, the first of which is to check the distribution of the center of gravity of the body on the pedals. We need to take into account that when we pedal, the center of gravity is usually located approximately near the vertical line of the shoulders. With the help of others, we can check whether the upper part of the shoulder is as close as possible to the vertical line of the pedal axis.
With the saddle in this position, it is important to check whether we are too extended or too compact on the bicycle. The former is easy to find if we have to grab the handlebars with fully extended arms or cannot easily hold the curved part of the handlebars, which means that we may be too extended. The latter often causes discomfort in the upper back and is particularly noticeable when the elbows are bent too much.
However, the key to verifying that the adjustment is correct lies in the ride itself. If we can ride for a long time without moving in the saddle, the adjustment is successful. If we tend to move forward or feel that the saddle is too far away from us, this indicates that we need to re-examine the setback adjustment of the saddle, although as we mentioned before, any adjustment may affect other parameters.
