Well...I was thinking about the Tour of Wessex, then I saw this..
The Dave Lloyd Challenge - 140 Miles and 5000M of climbing. It takes in 'Blwch-y-Groes,' but for some crackers reason starts from North Wales....This Dave Lloyd bloke must be a nutter !!
http://www.davelloydmegachallenge.com/
Note that the route has 6 stingers !!
Route Description:
Leave Ruthlin
climb of Bwlch pen Barras
climb of The Shelf
climb of Horseshoe Pass (Back of)
climb of Worlds End
climb of Cymau Hills
Treuddyn Climb
Rhosesmor Climb
climb of Moel Arthur
Denbigh's "Road to hell" to Cerrigydrudion (Could be hardest road in the UK with any headwind).
climb of Foel Gasyth
climb of Bwlch-Du
climb of Llyn Brenig
climb of Bwlch-y-Groes (Back of)
climb of Pen Bryn-y-Fawnog (Climb from Lake Vyrnwy)
finally the"Stingers"
Bwlch Garneddog
Tyn-y-Bwlch
Bettws Gwerfil Goch
Melin-y-Wig
Foel Fawr
Clawdd Newydd
Then downhill after Clawdd Newydd for 4 1/2 miles to Ruthin.