I've been using a Magellan Sportrak Map on my bike recently. Kind of
overkill, but it has a moving map display which is actually pretty
nice--combined with street / topo maps. I can come back later and download
the tracks, which is mostly a curiosity, but I suppose I could actually make
my own trail maps that way. Altitude encoding isn't great, but it's not too
bad--I can look at a an altitude profile of my tracks after the fact. It's
surprising how well it does in tree cover--sometimes I lose the signal, but
it seems to hold it better on the bike than when walking. My guess it it's
somehow a kind of 'window fan' effect.

Anyway, here's a GPS track from riding the 'Potowatami Trail' (southern
Michigan) on Saturday. The straight line throught the lake is where I lost
the signal in dense tree cover:

http://www.fototime.com/C232670A6C1B8F0/orig.gif

Mark


"Jim Sherman" wrote in message
...
I have never used a GPS before but would like to get one to calculate
elevation, grades etc especially on hilly routes. My cycle computer
already has speed distance etc. The Garmin Etrex seems to get the most
positive reports. But that's from the general public. How about bikers?

I'm not too interested in preprogrammed routes (though I probably will
after I get it). More interested in downloading data to a computer
after a ride to get a visual display of what I have done. Will it do
this? I expect it must update your position extremely frequently or
even constantly otherwise a slow climb followed by a fast descent would
give a strange readout.

Possible with the GPS or with add-on software?

Mountable on a bike? Can you just carry it in your pocket?

I read someone's post about how he had to edit his route after
downloading as it included his car ride home! I would expect it to have
some kind of mark feature to mark beginning and ends of routes.

Since I'm brand new to these things any advice is welcome. Thanks.