Yes, bananas are great fuel for cyclists. Many athletes eat bananas before or during a ride because they contain natural sugars (carbs) for energy but aren’t too harsh on your stomach. Plus, research suggests that bananas contain unique compounds that may improve cycling performance 
One medium banana has 422 milligrams of potassium, an electrolyte that helps with muscle contraction, nerve function, heart rate, and fluid balance, and is lost through sweat. Moderate to intense workouts can affect cellular potassium balance, so athletes are encouraged to eat potassium-rich foods like bananas 
 Nieman DC, Gillitt ND, Sha W, Meaney MP, John C, Pappan KL, Kinchen JM. Metabolomics-Based Analysis of Banana and Pear Ingestion on Exercise Performance and Recovery. J Proteome Res. 2015 Dec 4;14(12):5367-77. doi: 10.1021/acs.jproteome.5b00909. Epub 2015 Nov 23. PMID: 26561314.
 Kerksick, C. M., Wilborn, C. D., Roberts, M. D., Smith-Ryan, A., Kleiner, S. M., Jäger, R., Collins, R., Cooke, M., Davis, J. N., Galvan, E., Greenwood, M., Lowery, L. M., Wildman, R., Antonio, J., & Kreider, R. B. (2018). ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition, 15(1), 38. https://doi.org/10.1186/s12970-018-0242-y