The Challenge Griffo XS 33 is a lovely tyre - while it lasts. Your milage may vary, but mine was about 1500km, which is nowhere near enough for a $A70 pair of tyres no matter how sweetly they roll.
The Griffos are light and supple and smooth and fast but I'm hearing stories about their durability from other rides and now experiencing them myself. On our 60km ride last weekend, the tread started lifting on both of my tyres as shown below. Each had done about 1500km.
|Front tyre showing section of tread lifting.|
|Second area on front tyre with lifting tread.|
|Rear tyres, lifting tread has torn at leading edge.|
With durability issues like this I advise steering clear of these tyres. Admittedly they're puncture resistant and were only just starting to wear on the centre section, so I think would otherwise have been good for around 4000km, but tread problems like this are a safety hazzard.
I suspect the problems I and others have experience is a weakness in the glue used to attach the tread to the casing that the folk at Challenge will get on top of in time. I hope so, because for a while the Griffos seems to have been a solution to the problems raised but not solved by some of the Grand Bois tyres.
(My far more favourable initial impressions of this tyre can be found here.)