GPS devices are available with accurate speed, and after a couple weeks with my new Garmin Fenix 2 GPS watch I believe it's accurate. It's the first GPS watch Garmin has made with a mode specific skiing, so folks here might be interested.
I'm very confident in its speed because:
- it has 1 sec recording and 3d speed correction from a barometric altimeter,
- I've ridden my bike with it and it very closely matches my calibrated cyclocomputer,
- I've run with it and it quickly picks up very small changes in my pace, and
- there are online tests of similar garmin devices showing them to be highly accurate, like here and here.
I have yet to hit 40mph according to the watch, and I (of course) think I ski fairly fast. Here are my runs with the three fastest top speeds I've recorded in three days skiing:
Copper Mountain - Steeps on Spaulding Bowl to Bumps on Sawtooth
That 39.3 mph peak is the fastest I went in three days skiing with the watch. It was tucking on the runout at the bottom of Spaulding bowl to get up the little hill on the cat track to get over to Sawtooth. It's also interesting how my speed in the bumps really slowed at the bottom as the bumps got bigger and firmer (and I got tired).
Copper Mountain - Cruising Andy's Encore to Oh No, then Bumps on Far East to Too Much
I hit 34.3 mph straight lining it (no tuck) down the top of Andy's Encore on my way to the A lift bumps. It was a completely empty run, and I was moving fast because I had 10 mins and a mile of bumps to ski to get to the Alpine lift before it closed.
Mary Jane - Top of Eagle Wind lift to Sterling trees to Rifle Sight trees
I hit 37.4 tucking before the uphill side-step to get back to the Jane from the top of Eagle Wind. That's my second fastest speed in three days skiing, and the only other time I tucked. Based on all that, I have a hard time believing one can hit much more than 40-45mph without tucking.
I'm on 111mm Rossi Sickles and wearing a baggy jacket with a hood for all those runs. I wasn't trying to set speed records, rather I was just doing my normal thing on the hill, and lucky enough that meant really nice soft snow
Are these 50-60mph speed demons tucking down groomers to see how fast they can go, like the radar guys at Snowbird? If that's the case, I think it's possible they are hitting those speeds. If not it's more likely the app is telling them a spurious max speed.
If anyone really wants to see how fast they really ski, get one of these watches and get rid of the app. And.... rather than going for max speed, see if you can beat my time down a mile long bump run