In reply to taffyboy:
> (In reply to Jamie B) to be honnest im fine with abing. as for backing it up with a safety rope, the answer would have to be no. never found the need to do it.
Err ... this doesn't sound quite in the spirit of your original post. You may be fine with abbing but your mate may well not. It's not much hassle to take a belay next to the ab rope and use the climbing rope as a backup - if only for their first time down.