I haven't ridden a TriCross, but I have looked closely at them with an eye towards buying a bike I can use for cyclocross and also for major hill climb road rides.
I think that either the specialized or the trek cyclocross bikes would be an EXCELLENT choice for you.
They are sturdy and designed to take abuse, but they are still VERY road worthy bikes. Replace the slower CX tires with some road slicks appropriate for your weight, and go for it.
RE: Can I take a cyclocross bike on a 50 – 70 mile ride, and keep up with the road bikes (15-25 mph) without killing myself?
As for keeping up with roadies, your weight and fitness will be the only factor. And at 270 lbs there's a good chance the more upright position will be better for you too.
And yes, you can do 50, 70, even 100 mile rides on those bikes. I was thinking specifically of a CX bike for a 130 mile ride with 14,000 ft of climing, some on gravel roads.
If you buy either the specialized or the trek cyclocross bike, you will never actually "need" another road bike. Although you might eventually want one.
Last edited by nycphotography; 08-15-07 at 05:38 AM.