&gt;  I suspect the long-term problems with biking are more 
&gt; because bike designs often maximize performance over 
&gt; long-term joint health.<p>Eh, yes and no. The modern road bike geometry looks the way it does because of the rules in the governing body (the UCI). Up until very recently, they were more interested in keeping tradition, then technological improvements. Think of a bike geometry and design much like an F1 class of race cars.<p>A faster bike on the road would be a recumbent, and by quite a bit, as recumbents are much more aerodynamic. An added benefit to some is any saddle issues could go away, as there&#x27;s no saddle, just a seat.<p>I could also see that the aggressive posture needed to maximize aerodynamics on a regular road bike in an attempt to squeeze out the maximum amount of aerodynamic advantage on a platform that&#x27;s really not all about that could cause problems in some people, and relaxing this would be more comfortable, without a doubt - exactly like you have observed. You do need an amount of strength and flexibility to stay in those aerodynamic postures.<p>I&#x27;ve had minor knee issues with riding bikes (and I ride a lot of them!) I was fearing the worse - overuse sounded plausible. Rather, it was simply a muscle imbalance from riding so much, which was pulling me knee in funny ways. PT, stretching, and specific exercises - as well as getting <i>fit for my bike correctly</i>, I&#x27;ve cleared that up, and since have ridden thousands and thousands of miles.