What if a CX frame was made just like a road frame only it had slightly wider clearances, canti studs and a higher BB -- would it break?
Such a frame might weigh a couple ounces more than a road frame just due to the canti studs and the fractional more mat'l required to widen the clearances a few mm's.
What I see on the market for frames in comparable price brackets is that a CX frame of alum, say, often seems to weigh up to a pound more than its road-frame counterpart. The carbon frames often also seem to weigh a fair bit more.
Does a CX fork have to be beefier?
Are there known failure points for road bike frames, forks and parts when used for CX?
When roadbikes were used for CX in the, say, 70's and 80's -- back when CX was much harsher -- were those bikes known to have shorter lifespans? ...And to break in certain known places that we now know to reinforce?
I used to use a roadbike for CX back then and it held up fine until I started jumping it -- then the forks choppered -- but it was fine til then. I never heard of CX 'wrecking' a roadbike or even wheelset. These were 20-lb steel roadbikes with 26-28mm CX sewups.
Do we know better today?
I notice that the Giant TCX SL Aluxx weighs like a pound more than the comparable TCR. That's a +25% weight gain. Where did they put all that material? Can't be just studs and clearances. I don't see their marketing mat'l playing up any known points for reinforcement for CX frames. But that's just one example and it's hard to find exact weight info that always agrees. (It kinda looks like it's a half-lb in the frame and half-lb in the alum fork compared to TCR carbon fork.)