What forces are acting on a stationery bicycle?

What forces are acting on a stationery bicycle?
At rest, the bicycle is unstable because it has no base of support. But when the bicycle is heading forward, it automatically steers its wheels underneath its centre of gravity. Every cyclist has to overcome wind resistance. Most recreational bicycles have very poor aerodynamics. Newer bicycles are being designed with better aerodynamics in mind. The human body is simply not well designed to slice through the air. Bicycle racers are aware of the problem of wind resistance and over the years have developed techniques for reducing it. Bicycle designers and inventors have experimented in developing alternative bicycle designs and HPVs (human- powered vehicles) with an emphasis on better aerodynamic performance.
One force on a bike is Wind Resistance

Every cyclist who has ever pedalled into a stiff headwind knows about wind resistance. It's exhausting! In order to move forward, the cyclist must push through the mass of air in front of them. This takes a lot of energy. Aerodynamic efficiency (a streamlined shape that cuts through the air more smoothly) enables a cyclist to travel heaps faster, with less effort. But the faster the cyclist goes, the more wind resistance the experience, and the more energy they must apply to overcome it. When racing cyclists aim to reach high speeds, they focus not only on greater power, which has its human limitations, but also on greater aerodynamic efficiency.
Aerodynamic drag consists of two forces: air pressure drag and direct friction (also known as surface friction or skin friction). A blunt, irregular object disturbs the air flowing around it, forcing the air to separate from the object's surface. Low pressure regions from behind the object result in a pressure drag against the object. With high pressure in the front, and low pressure behind, the cyclist is literally being pulled backwards. Streamlined designs help the air close more smoothly around these bodies and reduce pressure drag. Direct friction occurs when wind comes into contact with the outer surface of the rider and the bicycle. Racing cyclists often wear "skinsuits" in order to reduce direct friction. Direction friction is less of a factor than air pressure drag.
On a flat road, aerodynamic drag is by far the greatest barrier to a cyclist's speed, accounting for 70 to 90 percent of the resistance felt when pedalling. The only greater obstacle is climbing up a hill: the effort needed to pedal a bike uphill against the force of gravity can offset the effect of wind resistance.
Although there is ways Reduce resistance
Frame builders and designers have been working on creating more aerodynamic designs. Some recent designs have concentrated on shifting from round tubes to oval or tear-shaped tubes. There is a delicate balancing act between maintaining a good strength-to-weight ratio while improving aerodynamic efficiency. Improvements to wheels have made perhaps the biggest impact.
While improvements to frames have improved aerodynamic performance, the cyclist is the largest obstacle. The human body is not very streamlined. Body positioning is important; some cyclists use "drop bars" to allow themselves to reduce their frontal area, which helps reduce the amount of resistance they must overcome. Reducing the frontal area helps riders increase their speed and their efficiency over time. In addition to positioning, small details like clothing can also make a big difference in reducing "skin friction." Tight-fitting synthetic clothing is worn by almost every professional rider, both road and mountain. Many recreational riders are also wearing bicycle clothes for the improvement in aerodynamics as well as comfort.
It can be tough being a cyclist but we have made many improvements since 1817. The Bicycle faster than walking but can be very frustrating knows all these forces are holding you back.