I've seen a few pictures of Slipstreams Felt's with PT on stem and a blue sensor on the chainstay, that would seem to be a cadence or speed sensor, but not like any Saris cadence/speed wireless unit I know of. Any ideas what they are?

Most likely, they're the transponders used to time and classify the riders.The units transmit an identification code to a detection loop taped across the road surface.The loops are connected to a decoder which puts an accurate timestamp on each rider. Because many riders cross the finish line at almost the same time, the transponders are attached to all bicycles at the exact same spot—1.20 meter behind the leading edge of the front tire.

That makes sense, I was thinking/hoping that Saris may have been putting out some new technology. Like a PT compatible with the Garmin 705

I was thinking/hoping that Saris may have been putting out some new technology. Like a PT compatible with the Garmin 705

I have no idea what you're talking about, but I'm old and still use downtube shifters to shift with and Tressostar to wrap my bars with. :D

I have no idea what you're talking about, but I'm old and still use downtube shifters to shift with and Tressostar to wrap my bars with. :D

PT = powertap

HTH