I get a bout of coughing (for 30 min) after biking, esp when i start talking, is it asthma ? happening for a year now.

Exercise asthma: Exercised-induced asthma is asthma. Everyone who has asthma has symptoms with aerobic exercise like cycling. Those with intermittent asthma may only have symptoms like coughing when they exercise. A bronchodilator like albuterol is often all that's needed. If exercise triggers coughing occasionally use albuterol when symptoms occur otherwise use it before exercise to prevent coughing. It works!

Could be: Coughing after exertion can be a sign of asthma. However, it is best that you discuss your symptoms with your physician so that other causes can be ruled out. If asthma is the most likely disgnosis, they can prescribe you an inhaler medication that can help with your symptoms.