Sold forza...Is my save safe on the cloud?

Ok guys here is one for you.

I no longer own an xbox one, But will my forza save data be on the cloud if and when i come back to playing forza 5? Will my credits still be there? will my cars still be there?

Pure guess, but I imagine it will be.

Yes, I sold my xbox one 4 months later my mum brought my son one and my game was still complete.

Your cloud saves should be attached to your profile, not the console. That’s how you can play your stuff at a friends house for example. When you get a new Xbox and sign in, there is an option in the settings for “Make this my home Console”. Choosing that should make all your cloud saves synch to the new box and your profile with it.