What are the best maps for MTB’ing and road cycling in the UK.
Is it worth buying the garmin discoverer maps or just going with a free open source version?
Didn’t get any maps with the device only the bog standard one, i.e. just follow a line.

Give the OSM ones a go and see if you like them, they’ve free.

Openstreetmaps here

Get yourself a micro sd card and try these first for free.

If you want more detail off road the OS maps are available online from Garmin – Birdseye imagery – £20 per year for basic package (gives an area of map to download, its up to you where you chose).

Great thanks, the Garmin maps are really expensive!

Anyone use the Birdseye maps?

Yes I downloaded some to go to France recently and they work really well. You can view on computer screen via Basecamp too. Not particularly costly at £20.