In reply to JAnders48: If you're going to do the big routes round Ailefroide, you'll really need two ropes for abseiling. Some routes are set up for 30m abs, but often you'll need 2 x 50m.
The guidebooks we were using showed the abseil abseil points and generally they were 30-40m apart. I remember the Orage d'Etoiles, for example, had long abs.