My doctor said if it is in your head you can ride, in the chest stay home. I on the other hand cannot ride with a sinus infection or head cold, I am too miserable to sit upright and too out of it to be safe on the road. I can handle a low intensity hike and that is all. I was cleared to ride with bronchitis after it calmed down. Bronchitis lasts 4-6 weeks so I rode with it when the weather was warmer and at a low intensity. HOWEVER at the start I would not ride since my own brother worked hard with bronchitis and had it turn to full blown walking pneumonia which put him in bed an entire winter break from his senior year of high school. Maybe try a short easy pace ride and judge your own body.