Back Soreness

[fourflys]

So thought I would pulse the collective here.. I will say it sucks being off the bike for ~10 yrs and then coming back with all of your preconceived notions of how your fitness, etc should be..

Up front, I will say I realize I need to ride more and gain more core strength..

Having said that, I had an observation that led to a "am I doing it right?" question..

At 5'9" with a true 31" inseam, I have short legs for my height.. most traditional saddle height formulas have me around a 68cm saddle height. When I have my saddle at 68cm, I will typically get soreness in my lower back, right above/at where I bend forward. If I lower my saddle height, the pain goes away..

so that's good you say, the pain is gone! well, at that saddle height I have, what I assume, is too much knee bend at the bottom of my pedal stroke..

could I just have a wonky body mechanics thing going on? Do I just need to ride more and gain core strength and eventually raise my saddle back to ~68cm?

The other weird thing is I tend to have to push my saddle pretty far back on the rails (with a set-back post) to get to a point where I don't get numbness in my hands.. again, I realize some of that is core strength..

Thoughts?