Hi Jen....

For a bike leg of a tri, you are basically doing a TT. Do you already know the course you'll be riding?

Anyway, most, but not all, TT's are taken with a fairly high cadence, say 90-110 in the flats, and obviously lower in the hills.

Not everyone is the same though, as you'll find a cadence that tends to 'feel' better, more natural than others. If I were doing a tri though, I'd attempt to keep it higher than lower in hopes of saving something for the run - rather than pushing a big gear.

A cadence sensor would be useful to tell you where you are though in time I bet you will start to almost know what it is, w/o looking.

Some of this whole desired cadence thing, is practice but some is just mental and being focused.