I’m sorry about my english, is a little bad.
I just finist to build my new carbon fiber seat.
I made it with carbon fiber and has an improvement respest to the others.
I have put two “handlers” back for better handle of the seat. That provides a new form to the sandle.
Weight: 156 gr.
I haven’t tested yet, but I will soon.
Some pictures to see:
A little more about the construction process:
Kypa Nº2 Sillín de fibra de carbono
I clicked on your link to have a look. Did you make that seat base with a fiber-glass core? I think that is what you said but my spanish is even worse than my french. If you did 156g is really light, I hope it holds up.
Cool bikes, I especially like the first one. Have you ever made any unicycle frames?
Sweet! Thats awesome! I used google translator 
That’s awesome, really really light too…
All seat is on c arbon fiber, I only put a layer of carbon fiber in the middle for the thickness, but is insignificant.
I hope this seat will be strong.
About the bicycle my fisrt bike was on carbon fiber because I don’t know welding, and the second one Shark bait I made welding. No very good weldings, but it works.
