yello said:Brave. Seriously. It is certainly one of the tougher 100s in the SE.
Grimpeurs are at the serious end of the scale. 1700m of climbing in 100km is pretty damn hilly. Not impossible at all, but probably not ideal for a first Audax unless you really *REALLY* enjoy lots of climbing.

If it's local to you, you might want to look at the map (on the calendar entry page on the Audax website) and try and work out where it goes and give bits of it a try. That'll give you a feel for it.