In reply to hindu: I take a 30 but I' considering getting a 40m.
2 weeks ago, if you read my heavily dog-eared and annotated guide to La Grave and the surrounding area you would have read the following sentence:
"Climb up 10 m to the ab (bolt in corner) 2x 30m ropes required, 2 x 40 better."
It now reads:
"Climb up 10 m to the ab (bolt in corner) 2x 40 m ropes
required "
I'll leave you to fill in the gaps.