"Carbon isn't just for road bikes any more. All the major bike brands have been making carbon mountain bikes have in use for many years. With gravel rides/races becoming more popular gravel specific geometry carbon frames are pretty normal now. The same is true for touring/adventure bikes being built as carbon frames. Just about any frame type you want comes in a carbon version now.The idea of taking a time trial bike and making it a fat bike seems unique but where would you even ride this? Riding a time trial geo frame on gravel would be pretty unstable and riding on the road would just be really slow. It's really just a show bike and it's not the first carbon fat bike. The Trek Farley (fat bike) comes in a carbon version and several of the other large brands have had carbon versions of the fat bike."