A good craftsman never blames his tools, as the saying goes. But don't tell that to Chris Horner -- at least not for a couple of days.

The 44-year-old pro road racing cyclist was on his final lap with a chance for a strong finish in Sunday's Philadelphia Cycling Classic. Then the unthinkable happened -- the chain fell off of his bike.

After struggling in multiple attempts to put the chain back on, Horner finally couldn't control his frustration, his bike the object of his wrath.

According to Cycling News, Horner is just starting to regain his racing form after battling a lung infection for two years, so having his chain come loose on the final lap of what could have been a comeback race for him must have just been too much.

Horner finished in 45th place, and was penalized by Union Cycliste Internationale, the governing body of cycling, for "unseemly behavior."

Chris Horner couldn't handle it when his chain came loose. Screen Shot/ibike365