Super Fast, Out of Control! - Louis Sachar - Bog

Suicide Hill is the ultimate test of bravery. Few have conquered the treacherously steep slope without completely wiping out - or so the legend goes. And rumour has it that Marvin will be taking it on. Only Marvin isn't so sure. His new mountain bike is enormous - he can barely climb up on to it. And changing gears is out of the question.