I want the garmin to grab my info (power, speed, cadence, hr, etc) every second. The problem is that to do that, the 705 will only save 4.5 hours of data. According to the manual, you can (after 4 hours) hold the lap button to reset the timer. My question is how does this affect the data?

Will it then show up as two rides? (For example, when importing into SportTracks)
Or does it show as laps?

Has anyone tried this?

I did a 200 mile ride and did just that. It saved both rides when I downloaded it to the computer a few days later.

It will only show breadcrumbs for the last few hours but it will store all of the data in the TCX file. Don't reset the timer, there is no point.

If you use smart recording how does that affect power data? Just wondering as i'm about to order a power tap.

It does Bad Things™

Really? Are you sure? According to Garmin, if you don't reset the timer, it will overwrite the history from the first 4 hours with the next 4 hours.

You've got yours set to every second and it actually saves the data (altitude, gradient, speed, power, etc) from a 6 hour ride without resetting the timer?

Yes, I'm positive, I do it all the time. Like I said, it only keeps part of the data "in memoy" but it logs all of it to the TCX file. Think of it as the difference between the RAM and the hard drive on computer. You can see this clearly in that the map and the elevation profile screens don't show the full data from the beginning. It also affects what it shows when you look at the map data from the "history" menu option. But again, the actual saved data is complete.

For example, this was a single ride file: https://connect.garmin.com/activity/29311879

Just to confirm, I don't use smart recording, and I have plenty of files over 4 hours.

Fantastic! Thanks to umd as well! I was able to go on a 5+ hr ride and didn't reset the timer but used every second recording.

I'm OK with the on screen elevation not showing the past from 4 hours earlier. Really I'm more interested in the gradient I'm climbing at the moment (which I have to say is one of the coolest GPS-related features of the 705).