Yes, if you are a regular coffee drinker, then it can be beneficial to have a cup before cycling. Studies show that consuming caffeine prior to exercise may improve performance, speed, power, and endurance capacity [1,2].
The recommended intake of caffeine for an ergogenic benefit during exercise is 3-6mg/kg of caffeine for a total of no more than 400-500mg/day (4-5 cups).
That said, if you’re not already a coffee drinker, adding caffeine to your routine can lead to GI distress and jitteriness. If you’d like to experiment with caffeine, try it out on rest days and start with half a cup of coffee to see how you feel.
For more information on cycling nutrition, check out our ultimate guide here.
 Jonathan D. Wiles, Damian Coleman, Michael Tegerdine & Ian L. Swaine (2006) The effects of caffeine ingestion on performance time, speed and power during a laboratory-based 1 km cycling time-trial, Journal of Sports Sciences, 24:11, 1165-1171, DOI: 10.1080/02640410500457687
 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