US President George W. Bush, for the second time in two months, took a tumble on his mountain bike while riding on his Texas ranch, a White House spokeswoman said on Monday. "During an 18-mile ride, as bikers often do, the president took a minor spill and scraped his knee," spokeswoman Claire Buchan said.
She said the president did not require medical attention after the spill.
Bush had a similar mountain bike mishap at his ranch in late May, when he toppled over while riding downhill on soil loosened by rainfall, and suffered minor cuts and abrasions.
Last year, he toppled off a high-tech Segway scooter at the Bush family estate in Kennebunkport, Maine
The president is spending this week at his ranch, while Democrats hold their convention in Boston to give Senator John Kerry their presidential nomination to oppose Bush.