Excellent race tubular for very muddy conditions. Deep knobs make this one of the grippiest CX tubulars we've ever ridden.Details:Use CyclocrossSize 28"Width 33"Weight 435 grTPI 300Carcass Super PolyBAR 1.6 3PSI 28-87Innertube LatexCHALLENGE 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 technical materials like Corespun (a cotton and polyester combination). Corespun is a thread from which we obtain a very supple and strong casing with low weights. The casings have a high TPI count that can reach over 300 tpi. Our production process avoids any vulcanisation process to enable all materials to keep their suppleness and flexibility.The tread is slowly hand glued on the casing which is previously mounted and inflated on a rim. By using this method the tread is relaxed on the casing and does not suffer any tension when inflated. The result of this is a lower rolling resistance, increase in comfort, more precise handling of the bike and better grip. Hand made tubulars are well known by professionals and is this type of tire that is preferred for the long stage races.To give the best possible grip in curves Challenge uses the most updated materials to obtain flexibility, suppleness and this results in absorption of irregular surfaces giving to the cyclist the best possible contact patch. The wheel avoids jumping and the tire will deform and absorb the irregularities acting in some way as a shock absorber. A special fabric is placed between the tread and casing to increase puncture resistance PPS (Puncture Protection System) technology.Comfort means reduction of harmful vibrations for the wrists and neck, these vibrations, will end causing inflammatory problems, as a hard tire will transfer all the vibrations directly to the racer body.If you have never tried a hand made product, go to a local shop and ask to see one. Touch the product and look at its construction and the side walls. You will immediately notice the difference.