As with anything to do with GPSs, I am confused, Paul. When we bought it in 2011 I was told that the map updates would be free for the life of the GPS. Some websites suggest I need to pay for this, others repeat that updates are free.
I updated (or rather failed to update it) by downloading Garmin Express onto my computer then downloading to the GPS.
I was also told at the time that this was not suitable for motorcycle use (not waterproof, not vibration proof) and yet I have found ball & socket handlebar mounts for this GPS on the Net.
Again, at the risk of being told that what I am about to write is incorrect........
My understanding of Garmin's policy re "lifetime map updates" is that you had to have registered your device with Garmin within a certain time after buying it.
It is not clear if you have either Mapsource or Basecamp on your computer? i.e. do you have a Garmin programme that allows you to create routes on your computer, that you can then transfer to your Nuvi? or do you create your routes on the Nuvi and save them on the device/ i am assuming the latter.
You can use either Garmin Express or Garmin Map Updater to download map updates to your Nuvi. If you just have the Nuvi and do not have Mapsource/Basecamp on the computer, then I would stick with Garmin Express to download map updates to your Nuvi.
You say that you "updated (or rather failed to update it) by downloading Garmin Express onto my computer then downloading to the GPS." So it seems that Garmin Express recognised your Nuvi and also recognised that the device has Lifetime Map Updates otherwise you would not have got through to the screen that gave you the information that the download was complete. if the download had been succesful, the device should have immediately recognised the new maps (I believe it overwrites the old maps). But your device is still showing the old maps, so it would seem that the download was unsuccesful. perhaps the files were corrupted, perhaps if there was an interruption to your internet connection during the download.
So try to run Garmin Express again and download the map updates again. However, I fear that Garmin Express may believe that you have already downloaded the maps, so you may have to go to the "Devices|Reinstall Maps" screen in Garmin Express.
If the Garmin software blocks you downloading the latest update, then you may have to contact garmin Support on the freephone number and explain the situation to them and they will almost certainly amend your online settings so that you can get the download and, at the same time, walk you through he download. It typically takes 20 minutes to get through to them, so do hang on.
Re whether the Nuvi is suitable for use on a motorbike, is on no relevance to updating the maps. If you have a set up that allows you to mount it and use it on the m'bike, then stick with it.
Good luck and let us know how you get on