Does the big to big plus 1 complete link still stand on a full sus.

The reason I ask is I’ve just fitted a 1×10 drive-train with a Zee rear mech, a 11/36 cassette and a 32t chainring to a Blur LTc and did the big to, well big, while the rear was at full travel which seemed to be where chain growth was the maximum and when uncompressed just adjusting the B screw can change the chain from nice and tensioned to flopping around like something very floppy.

Have I missed something or is this par for the course.

for 1x I used to take it to the longest length in the travel and then pull the mech nearly tight and chop there.
I would also have a chain device to take up slack with.

I thought on a full sus it was big to big +2 links with suspension fully compressed?

There cant be a hard and fast rule as different suspension designs have different chain growth.

Compress the shock to the maximum extension, shift onto big/big, pull the mech to almost fully extended, split the chain.

OK, how far is it safe to extend the cage on a rear mech, any photos would be helpful?

how far is it safe to extend the cage on a rear mech

Until it is nearly flat, maybe 20 degrees off flat.

The best way, IMO, is just to take the spring off or empty the aircan and cycle it through the travel. (you can just undo one end of the shock but a lot of frames can travel a fair bit further than the shock will let them so it makes more sense to do it with the shock in). Nice and simple, and foolproof.

I just went through this.

I put the chain on big to big then removed all the air from my shock and fully compressed it, then pulled the mech forward until it was at about 45degress (no protractor was used so maybe +/- 5) and then linked the chain at that point.

After my first ride I still had to take out another 2 links. Rides well now

HTH