Originally Posted by
big john
Most bicycle wheels are aluminum but more and more carbon rims are becoming available. Some of the lightest wheels on the market, and most expensive, are carbon tubulars.
The downside of carbon is they require special brake pads and don't stop as well as aluminum, especially when wet. Another issue is carbon overheats on some of the smaller wheel manufacturers although the big companies like Zipp seem to have overcome that issue now.