pros:
lightweight (on avg you save maybe 1 kg)
stiffer yet comfortable
I think the stiffer and comfortable stuff is largely hype, one feature carbon does have is generally really inconsistant construction. This is because while the surface is really nice the inside is inconsistent endings of the fabric, so you are really unlikely to have anything repeatable that one could claim behaves one way or another.
costs are coming down, especially if you look at the open mold models from a reputable seller
Carbon is getting cheaper, though it varies hugely. I was all set to do a carbon spar when the material costs were lower than wood, then 9/11 and the airbus blew the market up for about 10 years.
cons:
- no eyelets (need p clamps or something for the rack)
- can't weld it like steel
- low impact resistance
- more theft prone
- generally not designed for touring punishment
None of these are for real IF the market demanded touring bikes in carbon.
Eyelets are available on some units like the Tusk fork. But if your rig didn't come with them then it wasn't intended for this use. If you look at compound bows with carbon risers, or Olympic bows, they have all the regular screw-in fittings, and some of them, like the ones that hold on the limbs are heavily loaded.
Can't weld is a nothing, since the better option even for steel is bonding repairs.
Carbon has high impact resistance when properly modelled think arrows.
I don't think it will be stolen more if it is actually cheap. The cheap idea is based on boutique suppliers who are selling low, I don't think there is much evidence real carbon frames will actually be cheap.
Carbon always starts out breaking and being disappointing but if the demand is high enough it eventually becomes rugged, as in the youtube video I shared in a similar thread where they are driving a jeep over the carbon riser of a strung bow.
The real problem with carbon are the alloy fittings, and the lack of custom frame sizes.
now to address the cons..
- can p clamps provide enough support for a 30-40 lb loaded rack? furthermore, can a typical well built carbon seat stay handle the extra weight at the lower seat stay joints? (the answer varies with the build, so let's just make a sensible assumption that the frame is more a cx frame, and not a tarmac, cervelo, cannondale evo, or any of the race style bikes)
- how common are frame damage in a given tour? where are the failures most common? (if it's bb, head tube, or dropouts, it's probably game over)
- carbon fiber frames can be protected. people have used inner tubes, or other polymeric material that disperses the force. are these generally adequate to protect the carbon frame for a long tour?
- I'm sure there are ways to make a carbon bike look ugly (eg. wrap it in inner tube)
- I get it, Murphy's Law.. carbon fiber isn't designed to handle forces equally in all directions. but again, assume that it's a well built cx frame, not a superlight giant propel advanced sl... what are some specific touring scenarios where a carbon fiber frame would be at risk?
Basically these are concerns about your CX frame as a touring frame. These are issues that are made more difficult for being made out of carbon because there is no way of assessing the structure of the bike. Metal bikes are hardly immune to these issues, but to take the high road a properly designed carbon bike is engineered to align fiber with the expected loads. CX load paths are worlds different from touring load paths.
When someone says they like the Surly CX bike for their touring rather than the Surly touring bike(s) they are either making a sophisticated, or more likely ignorant guess about geometry. But the tubing could very well be identical, so you are not going out on a structural limb. The carbon bike should be equally reliable but there is no way of knowing what they did so there is a roll of dice involved.