My Garmin died this week and can’t seem to find replacement quickly.

I am going to Belgium next week and thought about using my phone to record the rides.

Do I need to have the data on? Or is it just working with GPS.
I’ll be using the Endomondo app.

It’ll work fine with data off. If you need mapping then obviously you’ll want to download that before you go (or on wifi while you’re there, if you have it).

Great thanks.

Data is cheap in Europe now. o2 costs me £2/day I think to use my uk allowance.

GPS on an iPhone requires zero data

Used it all last week (and many times before) with no data service it works fine. Download the maps.me app before you go or load local maps when you have wifi

Don’t need the map as it is a family holiday and just doing short rides early in the morning. Went last year so have vague idea of where I am going.
Taking the London Road This year so I can explore a bit more some off road sections.

Going to De Hann.