Funny you posting that - I saw a Tiger 800 going along with a broken strap just like this only a few days ago. It was wobbling up and down alarmingly, and that was just gently bimbling along a normal London street, going to work. Wouldn't fancy being directly behind him on a faster or bumpier road... I guess there is quite a bit of stress on those straps.
I also have an SC low carbon - I'm going to check my strap tonight.