Riding from UCONN to East Hartford along rt 44 I think. Longish descent, tucked, pavement had some slight undulations. At slower speeds it'd have been fine; at 50 mph or so it caused me to thump my chest on the bars. I hit the tire with my chin. The shock slammed my teeth together - I was lucky I didn't have my tongue out. I didn't realize until later that the raw spot on my chin had scabbed over.

My bars sit relatively close to the front tire because I have short legs. My bike at the time pictured below.