I know it has to do with stiffness - but I don't know the technical word for it.
My commute to work involves about a mile long downward slope riddled with uneven pavement and potholes. This is why I'm getting a cyclocross.
While test riding several bikes, I noticed that some were more fun than others.
Whenever I make for the long descent - I've notice that some bikes respond more pleasantly. They have a 'bounce' which make for an awesome fun ride - whereas some bikes cause unpleasant vibrations and feel brittle and fragile.
Please enlighten me if you know what I'm talking about. To date, the bike that was the most fun through all the potholes and uneven pavement was the cannondale XR7.
If you can help me figure out what to look for when looking for a fun ride (weight considerations be damned) please respond to this post, and I will love you forever. Are aluminum frames better than steel frames for this type of riding? Was cannondale more fun because of higher quality aluminum? or what was it?
"Spring" is a somewhat ephemeral ride quality, and there's lots of debate on the different components that go in to that. I'll say only 2 things.
First, tire width and quality has a lot more to do with it than anything else.
Second, the boys and girls at Cannondale do have alu pretty well dialed in. Not sure what it is, but I felt a similar snappiness with my CAAD7 road bike, when compared with other aluminum frames set up similarly.