Speaking of arthritis and knees (I know this thread addresses more performance)....my 4 bikes focus on keeping knees flexible and maximum range of motion at 71 years old, 6'4 and long inseam. I do 4 short rides a day. Start with lower handlebars and 165 cranks....then higher position and 170, then higher and 175 and finally cruiser position and 180 cranks. Gradually increases range of motion throughout the day. I cobbled together a 195mm set (fabricated from 2 cranksets) but had knee pain with these. Actually, would like to try these again with more conditioning and reduced knee stiffness (with diet, weight loss and supplements to reduce inflammation).