Basketball and softball are very common causes for Achilles tendon injuries. Expecially after age 40. The medical community generally recommends against surgery unless it's completely detached, because the scar tissue is stronger if it heals by itself. The bad news is, healing sans surgery takes longer - up to several months for a moderately bad tear. Find out from your doc when you can return to normal activity/do rehab, then work to strengthen the tendon/calf. You can find exercises to do by looking on the Internet. On the bike, you may want to lower your saddle a little bit (temporarily,) spin don't mash, and gently stretch the calf often.