Achilles tendon

If you want to continue riding/racing and you have explored most conventional avenues, you could always consider midfoot cleat positioning- some down sides:

• you will be out of step with the rest of the cycling crowd
  
• you will need shoes specially modified
  
• you will need to be on speedplay pedals
  
• you will have substantial foot overlap of the front wheel
  
• you will need to reposition your whole body on the bike- ass down and fwd, hands down and fwd probably
  
  

upsides:

• you will probably be able to ride your bike with few or no Achilles and calf problems