Richard and all,
I recommended switching to 170mm cranks ASAP simply for the sake of expediency, since 165s are often harder to find. If you can find 165s quickly to match your current cranks, by all means try them. As my friend Jessica Greaux, DC, reminded me, the best option is to have a thorough biomedical exam-- including an analysis of hip and knee flexion, etc.--from a qualified sportsmedicine PT, chiropractor, or physician and start adjusting one's bike with that info.
The subsequent comments regarding adjusting saddle position and height are invaluable as well. As John Muir once said, "Everything is connected to everything else in the universe." (He was a biomechanics expert before his time... :-)
Are there any CR list members near Roanoke, VA, who can help Richard with the names of bike shops that do really advanced bike fitting? The expertise of an experienced and careful bike fitter in a shop may be worth just as much to him as the bike-friendly medical professionals if my own experience is any guide.....
Jon Spangler who is still seeking bike fit answers for his "nonstandard" and "modified" physique in Alameda, CA USA
Message: 13 Date: Sat, 24 Jul 2010 11:28:33 +0000 (UTC) From: damien roohr <email@example.com> Subject: Re: [CR] Old Age vrs Crank Lengths To: RICHARD HOWARD <firstname.lastname@example.org>, Dale Brown <email@example.com> Message-ID: <735327606.351332.1279970913185.JavaMail.firstname.lastname@example.org>
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Richard- I agree with Jon-- - all of his points on bike fit are wise--
Also, do not forget to adjust your seat height accordingly - it should go up as your cranks get shorter - as a base point, that is... because if changing crank length is not the solution, then you might want to fiddle with seat height.. and I mean fiddle, as I am sure you know that differences of as little as 1 mm can have an impact on comfort.
Another thought (yup, Off Topic, but still...)- you may want to try using a pedal that gives you a lot of free lateral movement. I have had surgery on both knees and the original speedplay pedals have been terrific. they feel like you are walking on ice when you first use them, but your knees may like it. when you think about how quill pedals lock the ball of your foot in place, and compare that to how most people's foot twists a little on each step - you begin to see the wisdom of a free floating pedal for some of us.
Also, i do not have links, but Lennard Zinn (velo news, maker of KOF frames) has studied and written extensively about crank length and physiology, etc.
Linda Hudson Writing