Very nice bike shop on Atocha. The space is quite large and the staff is very knowledgeable. When I…read morearrived to Madrid, I needed to get a new bike - I went to Calmera and they told me to wait a couple of weeks and they were offering a big sale. Everytime I go back there's more deals to be had.
When I was unfortunately in an accident, I took the bike in to be looked over, and the maintenance repairs cost be 11 euros (including re-taping my handlebars). I think it wouldn't normallly wouldn't be so cheap - maybe taking pity on me.