A recurrent disc herniation probably is still present but not compressing the nerve root as significantly as the initial herniation was. Flexion (bending forward) will tension the nerve root over the herniation. This is most likely why cycling aggravates the nerve but weight lifting (where you keep your body line straight) does not cause as much aggregation.
If this is the case, an epidural steroid injection might be helpful.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.