Hi guys I’m after a gps watch. Preferably with the afore mentioned. Can anyone reccommend. Also is to have this function the only way to see metres climbed during riding ?

Cheers

Garmin 910xt has it, also older 310

You need it for instant read out, but the non barometer ones correct once you upload using the map data.

Depends what you need really. By the way non baro ones do attempt this, but gps not good for this..

Suggest googling dcrainmaker if you have aan hour or so..

IMO a gps watch is inferior to a dedicated gps unit. Aside from less functionality it obviously has a much smaller screen. Why a watch ?

Cheers for the responses guys. Needs to be a watch as I ell use it for running and walking every now an again

Why are the gps watches etc no good for altitude? When I fly, they are as accurate as a barrometric altimeter, and more so at the end if the day when pressure at sea level has often changed from when it’s set.
OP, this isn’t to say that your asking the wrong question, I’m just intrigued.

Why are the gps watches etc no good for altitude? When I fly, they are as accurate as a barrometric altimeter, and more so at the end if the day when pressure at sea level has often changed from when it’s set.

Yes, GPS is pretty good for your current elevation (assuming you have a reasonable view of the sky) – usually within 5m or 10m.
The problem is it can fluctuate. ie even if you are cycling along a flat road, the elevation can go up or down by a few metres. And all of these little variations can add up over a ride, so the total ascent/descent will be inaccurate. Plus if you briefly lose the GPS signal, you can get spikes in the elevation, of up to 50m or more.
The barometric altimeter should smooth out these variations, to make the total figure more accurate.
Or you can smooth the elevation in software after downloading from the GPS. Though this may smooth out actual small hills that you cycle over.

As for a GPS watch with barometric alitmer, also worth a look at the Garmin Foretrex 401. It is fine for walking, or easy to strap to the handlebars for cycling. Though maybe a bit big for running.

Garmin 910xt has it, also older 310

310 doesn’t have it – only 910. That’s one of the main differences between them. Calibration was a bit rubbish initially on my 910 – resulting in some awkward step changes in altitude in recorded data as it sorted itself out – but that now seems to have been fixed in a firmware update. AFAIK apart from 910, the Suunto Ambit is right now the only available option for an all-in-one GPS watch with baro altimeter (though Polar and Suunto do ones with a separate GPS unit you wear on your arm). Check out the reviews of dcrainmaker to compare, but I have to point out that I disliked the software available for the Suunto watch I had before, and prefer that for the Garmin, and it seems you can only display 3 data fields at once on the Suunto which would be a downer for me – on the other hand there are things I dislike about the 910 firmware which the Suunto seems to do better!

IMO a gps watch is inferior to a dedicated gps unit. Aside from less functionality it obviously has a much smaller screen. Why a watch ?

It’s not inferior if you want to use it as a speedo for running as the OP has answered – it provides much more functionality in terms of tracking your performance. Also handy for all sorts of other sports use where a normal GPS is awkward (I also use mine for unicycling, rollerskiing, kayaking etc.). Exactly what functionality are you missing anyway – my 910XT will provide a continuous location display, a map of your progress and follow a track.

Why are the gps watches etc no good for altitude? When I fly, they are as accurate as a barrometric altimeter, and more so at the end if the day when pressure at sea level has often changed from when it’s set.

What are you comparing with and to what level of accuracy? I’m assuming with an aircraft altimeter you’re measuring 1000s of feet, so only comparing to within 100ft. Instantaneous GPS altitude is fine to within ~20m accuracy, but there’s no way you even get to the 5 or 10m accuracy Craig suggests reliably as the geometry of GPS means that the vertical accuracy is far worse than the horizontal. As Craig says, you also get a lot of variation which really messes with ascent calculations. With a calibrated baro altimeter you can get precision to within 1m and you don’t get variation when you’re not ascending or descending. If you’re doing sports such as running (biking, skiing etc.) up and down hills/mountains where the amount of ascent is a significant feature then such accuracy/precision is important.

The bonus with a watch like the 910XT though is that it has both GPS and baro altimeter – it uses the GPS to calibrate the baro altimeter, so you get the short term precision of a baro altimeter combined with the long term accuracy of GPS (if you average GPS altitude over long enough you do get accuracy down to <1m). Hence getting rid of the issue of changes in pressure on a baro altimeter. I have to admit I’m still to be totally convinced by how well this works with my 910XT – the early firmware was poor at this, and I’ve not had a chance to fully evaluate since the latest firmware updates, though it certainly seems to perform a lot better than it did. Though I certainly expect Garmin to get this working well at some point – the accuracy of the altitude on my very old Etrex summit which used a similar combination of sensors and calibration is superb.

As for a GPS watch with barometric alitmer, also worth a look at the Garmin Foretrex 401. It is fine for walking, or easy to strap to the handlebars for cycling. Though maybe a bit big for running.

Though apart from being a bit big for sports use on the wrist, it also doesn’t have all the sports specific functionality of the Forerunners.

I’m comparing a glider altimeter (barometric) with a gps liked to a c3 glide computer and a palm pilot runnin xc soar. I’ve never ever seen a spike, the gps altitude is down to single feet and follows the barometric pressure precisely. A spike of 50m would make a final glide calculation more than a little scary! I suppose that the speed of flight could well mean than spike are ironed out before the spike actually shows as there has to be a delay, as there is with the barometric.
Sorry op, this still doesn’t help you!

The GPS altimeter accuracy will be affected by the number of satellites in view, so in steep sided valleys and under heavy tree cover the accuracy will be reduced.

the gps altitude is down to single feet and follows the barometric pressure precisely

There’s no way that sort of altitude precision is physically possible from pure GPS altitude (not unless you’re averaging over far too long a period for the numbers to be any use to you for gliding), so there must be something else going on there. Are you sure that isn’t something else apart from GPS providing altitude information?