Oh, sorry. TT frames have super agressive geometry, so you would expect a longer top tube. It's not really so weird though, because the frames are so short. Imagine in your mind a standard road bike. Keep the crankset and head tube where they are. Then make the seat/seat tube more vertical and move the rear wheel forward. The rider is shoved forward a lot. So for the bike to fit the top tube length in actual measure is shorter than you would think because the bars are meant to be under the riders elbows.

I think I see your confusion. In my post above, I mis-typed head tube, I meant seat tube. I edited the post above.