No, cyclists don’t need protein supplements such as protein powder and premixed protein shakes
protein powder and premixed protein shakes, but sometimes they can be helpful. It’s possible to get plenty of protein from food, however, protein supplements can be a convenient way for cyclists to meet protein needs.
Protein is a macronutrient that is found throughout the body in muscles, bones, teeth, hair, and organs. For cyclists, protein is important for muscle growth and repair after a tough workout as well as glycogen repletion.
The International Society of Sports Nutrition recommends a range of 1.4-1.8g/kg/day for cyclists, or 0.6-0.8g/lb/day 
Protein is abundant in animal foods, like meat, poultry, fish, shellfish, dairy, and eggs. It’s also found in plant-based foods, such as soy, legumes, beans, nuts, and even small amounts in vegetables. Cyclists who eat animal products can usually get adequate protein through food alone. However, vegetarian and vegan cyclists
vegetarian and vegan cyclistsmay find it difficult to hit the recommendations since plant-based foods often provide less protein per serving.
Many protein supplements are convenient-- just dissolve a powder in water -- and serve upwards of 20 grams of protein. After an intense session on the bike, you may find it easier to down a protein shake than put together a protein-rich meal.
 Kerksick, C.M., Wilborn, C.D., Roberts, M.D. et al. ISSN exercise & sports nutrition review update: research & recommendations. J Int Soc Sports Nutr 15, 38 (2018). https://doi.org/10.1186/s12970-018-0242-y