Highest I've seen my heart rate go on the monitor is 195. On a moderately fast-paced ride, it usually hovers around 160-165, higher on hills. In a time trial (8 miles) I kept it at about 180 with a couple spikes in there for inclines. When I know I need an easy, recovery ride, I try and keep it 130-140 range.
Max heart rate is such an individual thing. All the charts can do is give you a starting point, but I don't believe any chart can tell you what your own max really is. I've got to get going now, later I'll find the site that tells a way to find your max heart rate while out on a bike ride. (Or if you live somewhere where they do testing, lucky you!)
annie
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived." Captain Jean Luc Picard