I ride a 2008 LeMond Poprad Disc on longer "non-competitive" gravel rides:
Gallery: LeMond Poprad Disc Review - BikeRadar
First Impression: LeMond Poprad Disc | Commute by Bike
Update: Lemond Poprad Disc | Commute by Bike
LeMond Bicycles Poprad Disc Cyclocross Bike Reviews
The frame is made of True Temper OX Platinum steel (
OX PLATINUM Bicycle Frame Tubing by True Temper Sports ). and way nicer triple butting than any 4130 steel CX bike that I have seen. 40c is the largest size tires that will fit in the rear. I don't see that as a problem though; as I do (in addition to gravel) single track on it very effectively.