Yup... I'm like Eden... try and lurk at or above my LT.

Typical HR pattern in a TT as follows...

In a TT I usually leave with such a rush of adrenilin that my HR seems to spike up to about 168-175 which is approaching my max, but after about 500 metres it settles and I then I wind myself up til it is sitting on 156-158bpm
158bpm is my lactate threshold as measured in a sports lab in 2007.

At the turn-around, or the half-way point in distance, I wind myself up more. I know I can sustain a good power output several beats above my LT for about 10km or 18mins and if my body is responding well I try to keep my HR at 162-165 for the last half of the course.

In the last 2kms I try to lift the speed/power output more and my HR often sits at about 168bpm for the last 1km of the ride - thats 10beats above my LT.

My distances for TT are between 18km and 25km long. 18-20km TTs are ideal for me, but I am still having trouble pacing myself over 25km... that extra 5km makes a significant difference.