I just started riding again 10 months ago after a 30 year layoff. When I got the new bike in 2007, it was fit to me at the LBS and I didn't have any problems whatsoever until I began putting in mileages of 65 and above.

From what I understand, after riding a while, the body changes and readjustments might be necessary as to fit but I didn't do that, guess I just got used to the initial fit and as long as it felt OK, I didn't give another thought.

Couple weeks ago, I set the seat obviously too high where the hips would rock with each stroke and then I would drop the seat a 1/4" at a time and re-test. Did this until the point where the hips didn't rock at all even at high cadences and it felt good. This new seat height was 3/4" higher than the initial LBS setting many months ago.

But now the question out of curiosity, what mechanics do you think were happening in the legs to cause the aching after prolonged riding? perhaps muscles need to fully extend to function properly? I don't know.

Thanks...knotty