I'm in. Done the 50 and the 80 twice. Time to step up to the big one this year.
Can you still enter the 100 and then ride the 80 if you're not feeling up to it?
There's a substantial difference between the two rides: not that the 100 is
that much harder, but the ascents of Fleet Moss and Park Rash, then the rides down Langstrothdale and Coverdale, and the views on offer, are inspirational. The ride down Wensleydale on the 80 is quite nice, but you're missing out on a lot.
It was complete carnage down Coverdale when I rode, mind - riders were so shagged out at the top of Park Rash that they seemed to lose all judgement, and I thought I was going to see someone go straight on where the road takes a sharp right after the first steep descent.