Just fancied it. Running a 1.8 Maxxis Medusa (left over from SS an MMayhem) and getting on with it just fine.

Will try 1.8 NN front - 2.1 RR rear. Depending on the trail conditions locally (dry as I type)and the Viking Challenge on 05th October.

Tim

"Shimano have been making disposable chainrings for years and they're been readily available after market as spares. They finally produce some decent carbon and titanium/steel ones but decide not to sell them."

 They're on the Madison list John, middel ring £95, outer ring £120.