Originally Posted by
Velodad
Just incase people don't realize it. All three of those frames are made of the EXACT same alloy.
4130 is an alloy that various manufacturers use to make tube sets from.
520 is a tube set made by Reynolds from 4130.
Maybe so. However, there are other relevant issues such as forming of the tubing. The 520 tubes are double butted and the top tube is ovalized. This can result in both a lighter and stiffer frame. Since I don't own any BD bikes, I'm not going to go out on a limb and say it's absolutely so, but based on the specs I'd say the Kilo TT frame is significantly better, and worth spending an extra $50 to $70.