We have a local TT that we do which is about 20 km and has 600 feet of
climbing in it with several sections of approximately 6% for more than
100 yards both going up and coming down. My best time is around 35
minutes for an average of 20.5 mph.

I've done this on a TT bike and on a normal bike and SURPISE! a normal
bike is faster. At speeds below 25 mph a TT bike adds almost nothing to
your speed. The difference in drag is almost indetectable and TT bikes
are generally heavier and accelerate slower.

Moreover, unless you spend countless hours on a TT bike the position is
foreign enough that you put out less power in that position.

Are you saying that 25 mph is the speed?

-RJ