Originally Posted by
sstorkel
Remember: the frame is only one of the many parts that affect how a bike feels. Things like wheels, tire pressure, fork, crank and handlebars also play a substantial part. As an example, I own an aluminum-framed touring bike which is every bit as comfortable as my high-end Cervelo RS road bike. How is this possible? The touring frame is riding on high-volume (700x35mm) touring tires inflated to a relatively low pressure (65psi vs. 100+psi). By the same token, the ride on my Cervelo RS is now somewhat less comfortable than it once was. Why? I switched from light-weight (read:flexy) 16- and 20-spoke wheels to stiffer 24- and 28-spoke wheels.
A truly great idea if you can do it, is to ride each bike with the same wheelset on. This will throw away the different feel of the different wheelsets that come with each bike and give you a true indication of how each frame feels. Of course the contact points will change characteristics somewhat, but not so much as what wheels will.