My bike is going on a carbon diet. Through a friend, who spends weeks every quarter in China doing supplier assessments for his employer, I have been “gifted” a carbon fiber steam and seatpost for my evolving gravel grinder. It seems that once his contacts at various manufacturers in China learned he was a cyclist they fell over themselves to present him with manufacturing samples that just happened to correspond to his chosen hobby. No one has gone so far as to present him with a carbon fiber frame, like the ones you might see on eBay, but I have no doubt the day is coming in the future when he returns with one of those.
Carbon fiber was a miracle material when I was in high school. Bikes made of carbon fiber, especially the Trek OCLV models in my local bike shop, seemed like space ships compared to our TIG welded steel bikes. Now it is everywhere and TIG welded steel bikes are the objects of desire due to their rarity. How times change, eh?
When compared with the OEM aluminum alloy stem and seatpost that were replaced the weight savings were nil to meh. The stem was a wash compared to the alloy version it replaced at 4.8 ounces. The seatpost weighed ~3.7 ounces less. I probably have that much variability or more in my own weight depending on whether or not I have taken a leak before going on a ride. This was definitely not going to be about a weight reduction.
What I was looking forward to was an increase in comfort. I put in a lot of miles on buzzy asphalt and gravel trails. After about two hours in the saddle the transmission of road buzz on your rear end gets old. With about two hundred miles on both parts I can safely say that there is a noticeable reduction in buzz. Nothing crazy, but every little bit helps when you are staring at putting on successive days in excess of 100 miles later in the summer.
Some of the comfort derives from the fact that I replaced a 6 degree rise stem with a 17 degree rise stem of the same length for a more upright position. I think that this has made a world of difference for my hands by taking some pressure off.