So, if you can't keep your HR low... maybe its just you?
Maybe you just naturally have a higher HR?

I don't know these things.

You seem to have a good cadence going... I find when I mash, my HR goes up now... it was the other way around when I first started cycling.

Spinning would send my HR through the roof - but I have been working specifically on cadence over the past 6 weeks or so because I have finally understood (after two years!!!) the advantage spinning in a race can be...

So now my body is used to, spinning does not push my HR up? Perhaps this has something to do with it? Are you getting your body used to higher cadences?