fast flight for a 110# bow?

I built several thousand of the original Fast Flight for Ken, Black Widow, in 1990 and 1991.
Don't remember making any larger than 20 strand.

You should be able to find out the breaking strength of a strand of the type of bow string you're using from the manufacturer.  Or, if you already have some of it, you can just pull a strand with a bow scale until it breaks and find out for yourself.  The string should have a breaking strength at least 4X the maximum weight of the bow.

For example, a 100# bow should have a string with a breaking strength of at least 400 pounds.  If a strand has a breaking strength of 50#, then you would need at least 8 strands, or 2 bundles of 4 strands each to get a bow string with a breaking strength of 400 pounds.  Probably you would add a few more strands to each bundle just to have an extra margin and to give a good nock fit.  If you made a 14 strand string with 2 bundles of 7 strands each, it would have a breaking strength of 700 pounds. 

If you decide to make a string with more than 7 strands per bundle, I recommend making 3 bundles with less than 7 strands each instead.  A 3 bundle string with 6 strands per bundle is stronger than a 2 bundle string with 9 strands per bundle.  The 3 bundle string will also look better and have a rounder shape.