Source for Free Topographic Maps?

[BikinOn]

I've just treated myself to an Oregon 600 GPS and while it will spend most of its time clipped to my bikes it occurs to me that the addition of a UK Topographic Map for the odd hike would be nice, especially since I've got a 4Gb card in it and even with OSM installed it has loads of spare space.

The Oregon didn't want to give me 3D view, so I take it there is little or no Topographic info in the OSM maps. Can anyone suggest a good source for free TOPO Maps of the UK?

[mcshroom]

How about these?
http://www.smc.org.uk/ContourMaps.php

[fuaran]

How about these?
http://www.smc.org.uk/ContourMaps.php

They would give you contour lines, but I don't think they would actually work for the 3D view (or elevation profiles, or hill shading etc). Its still very useful to have the contour lines anyway, it gives you a idea of the shape of hills, so useful for router planning etc.
There are various other free contour maps (usually based on the NASA SRTM data), but I think they would have the same issue. Probably because they don't contain the embedded elevation in the correct format.

I think the only maps with 'proper' elevation data are Garmin Topo GB or Garmin GB Discoverer, which are not free.

[hbunnet]

I have just tried this on my Oregon 550, using an OSM map with contours.  The 3D view works but is not very useful.

IMHO it's much better to read the contours.

The difficulty with maps using NASA derived contours is that the vertical interval is 20m or more so the  resolution is poor. 

[fuaran]

I think some Garmin models (Oregon and Montana) include a worldwide basemap with elevation. So that's probably what it uses for hill shading and 3D view (assuming you've not added more detailed maps with the required elevation data).

[hbunnet]

Yes I have the European topo map but I keep it disabled. (Model is Oregon 550T).

The OSM map I have installed and enabled has NASA contours so I think the 3D data comes from there.  However the 3D display is hopeless even for Ben Macdui!