I had a urethroplasty almost 4 weeks ago, and asked my surgeon about biking because I also biked a lot prior to my surgery. Post-op instructions for me were similar, saying no bikes/motorcycles/horseback riding after surgery. However, in my conversation with my surgeon, and his fellow, it sounds like they recommend no biking for at least six months but after that I can try to resume. They make it sound like it’s all about my level of comfort/discomfort while biking. The key issue is that you don’t want to do anything that blocks blood flow to that area, ESPECIALLY during your recovery period.
I plan to try and get back on the bike come spring-time… depending on how my recover continues to go! I already was using one of those seats designed to not cause damage to key blood vessels, but might look into something even more dedicated to that end.