What do your physical therapist and orthopedist (preferably of the sports medicine certified variety) say? Have you asked them?
Not being an expert, I would swap out those 175s for 170s ASAP. It is a relatively cheap and easily-accomplished experiment. Ask your sports orthopedist or physical therapist for advice. You will want to modify your seat position, too, I would think...
If they are not bike-fit knowledgeable, ask for a referral to a PT or sports chiropractor who is a bike fit expert. If those avenues fail, check back with your local bike shop(s) and ask their fitting experts.
Locally, I would recommend my friends at Cycle Sports bike shop in Oakland or my buddy, Jessica Graux, DC, who does great bike fitting in Berkeley, CA:
You might call or visit other local CR listers and shop owners in VA or thereabouts:
Wayne Bingham at Velo Classique (540-338-8376; PO Box 2069, Purcellville, VA)
or Dale Brown at Cycles de Oro (1410 Mill Street, Greensboro, North Carolina 27408; 336-274-5959)
(These are the only two references I can think of that are in your "neighborhood," but I'm in Alameda, CA and on the wrong coast to know who else might be closer to you.)
Jon Spangler who has less-than-pristine hips in Alameda, CA
Message: 5 Date: Fri, 23 Jul 2010 05:04:34 -0700 (PDT) From:RICHARD HOWARD <firstname.lastname@example.org> Subject: [CR] Old Age vrs Crank Lengths To: email@example.com Message-ID: <firstname.lastname@example.org> Content-Type: text/plain; charset=us-ascii
I am 65 years old and have been using 175 mm cranks since my first real bike in
1967. I have had a total knee replacement and lost enough range of motion in
the affected knee that it impacts on my ability to ride smoothly. The problem
is mostly at the 12 o'clock position of the affected crank arm. It is a struggle
to power over the top. I am thinking about switching to 170 mm cranks or even
165mm. Considering the skeletal shrinkage that also automatically comes with old
age, I am thinking that 165 may be optimal. Has anyone else had a problem
similar to this? Did you create any new problems for yourself while solving the