If I were to show up to a mountain bike race on a cyclocross bike would they let me start. I understand the types of terrain on which one is faster and on which the other is faster. I just don't know what makes a "mountain bike" race legal. Oh and it's just for uscf, not uci. Thanks.
I know that they allow MTB's to be used for CX races down here, but I'd think that a CX bike would be at a disadvantage ona technical XC course. Imagine having to portage while the XC boys are cranking away. Right tool for the job is my view
They are legal since 29ers became legal for racing. Not sure it's a good idea though. Last year a few racers decided to try their cross bikes at our provincial championship XC race. The course consisted of 5-6 technical areas, mostly descents with one technical climb, linked by easy trails. Some of these crossers were excelent athletes who would have been competing for the podium, all of them finished well down of where they likely would have on their xc rigs.
I also tried out my Jake the Snake at our local short track XC course the other day. The course has 0 technical sections, but is bumpy in places, I was much faster on my xc bike.
To me the big advantage of a cross bike is on smooth untechnical trails or on grass. The difference between 2.0 race tires and 35mm cross tires in grass is night and day.