Boston the original hotbed of north american cross and home to some of the nastiest courses if youre flying into bostons logan airport you better be ready for rain roots ruts and mud the bos even more aggressive than the pdxm has buttressed side knobs for outstanding traction in super muddy corners and off cambers and centre tread thats all bite when it comes down to a tractor pull key features tubular size 700c x 33cm tractor style tread for the harshest mud buttressed side