Deeper 33mm knobs for increased traction in deep mud speed and max traction all in one details use cyclocross size 2834 width 3334 weight 400 gr tpi 300 bead carcass super poly bar 16 3 psi 28 87 innertube latex challenge tubulars hand made all tubular and open tubular produced by challenge are special products machines are not able to produce them and the manual skill required in each step to obtain a good quality standard is very high the casing is produced with the latest techni