I've always wondered how many k's one actually travel when down-winding to scarbs or Trigg. So on Saturday I pushed the phone into a waterproof pouch, and turned on one of the many GPS tracking apps - runkeeper pro.

A bit nervous about the phone, but the bag worked a treat.

So here are a few interesting stats (how I rode anyway)
the ~5km downwinder translatest to 17.5km of distance travelled point to point
Time taken, 1 hr 9 mins (which includes launching and landing). Average speed 15km/h. Max avg speed over 1 min ~38km/h

The log is exportable into Google Earth or industry standard GPS log (.GPX).
For those lucky ones who got into the rotto race, this could be a fun thing to do. I sadly registered too late.

You can see the stats here... runkeeper.com/user/Coertdup/activity/60368505