In article ,
says...
I added some aero bars to my Trek 5200 a few weeks ago. They really do help
me to ride in a more aero dynamic position for longer times. I'm about 1.5
MPH faster too :-)
However, after riding about 20%-40% of the distance (usually ~40 miles) in
the bars, my legs feel stressed behind the back of the knees and sometimes
below the knee caps. I know better than to ignore these clues.

Do I have to re-adjust the seat or stem now that I'm riding in a new
position?

A lot of people move the seat forward a bit when they use aero bars. It
sounds like you might be stretching your hamstrings a bit in the more
bent-over position. I'll bet your legs adapt to it over time, but
moving the seat might prevent problems in the mean time.

--
Dave Kerber
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