Check Osage Beach, MO.
Big lake hereabouts.
Also check www.funlake.com
Thanks!
The following web site provides detailed information on different cities. Just type in the city, state, and it will provide all kinds of data.
here is the link for Osage Beach.
http://www.city-data.com/city/Osage-Beach-Missouri.html
You might also want to consider Springfield, MO, or Joplin, MO. Springfield is nicknamed the Queen City of the Ozarks; They are both very nice towns. They are also less hilly than Osage Beach for bike riding.
As an aside, my brother will ride his bike when the temperature is above freezing and there is no snow on the ground. There are usually several days in the St. Louis area during the winter months when he is able to ride his bike.