Thanks for that phmode, I do realise that radiators are susceptible too stone damage but I think there is a quite adequate honeycomb stone guard on there anyway.
I am not a born again biker, I have ridden bikes since I was 16. My last sports bike before the K was a 170 Bhp (at the wheel) 2007 Fireblade, the front guard was shorter and no guard on the rad. I ran it on Pirelli Diablo corsa rosso tyres that were good and sticky.we did well over 30k miles on that bike and never had an issue with the cooling system.
I was an engineer for 50 years and I understand that sticking a 100mm plank in front of the rad would reduce its efficiency. It seems as though quite a few guys have had issues with the cooling system and some have even said they have to pull over till the bike cools, and that's with the stone guard on.
I'm pretty fortunate now in being able to ride when the weathers fine, I also think that's the problem with the bottom corners on the rad, with the fan mount blocking the rad there's no airflow ,the dust builds and Blocks the core then rots it, I might even fabricate a new fan mount and try that.
Best regards. Mick