A carcass is essentially nothing more than a fabric weave. Depending on the requirements for the respective carcass type, this is folded into several layers in such a way that a wide variety of applications are optimally covered. Visually, the different carcass types cannot be distinguished, as they are hidden under the rubber coating of the tire. Technically speaking, however, they can vary greatly in terms of weight, puncture protection, and tire stability. Single-ply carcass A layer of rubberized nylon fabric is wrapped around the two tire bead cores and overlaps at the top of the tire under the tread. This means that the sidewall consists of two fabric layers and there are three layers under the tread. This is the standard construction of a bicycle tire carcass, which is supplemented by additional layers in many tires to optimize performance in terms of puncture protection, airtightness, rolling behavior, or other performance characteristics.
Two-ply carcass
Two layers of fabric are combined and wrapped around the bead cores. The finished carcass then has four layers on the sidewalls and as many as six layers under the tread. Maxxis downhill tires with the designation DD (Double Down) are manufactured in this way, for example.
Fabric density
The number of carcass threads per inch (2.54 cm) of tire fabric is specified in TPI (threads per inch). Low numbers indicate heavy and stable fabric. The higher the TPI value, the better the tire adapts to the ground and the lighter it is. This varies from 27 to 170 TPI. Tires with a high TPI number are more complex to manufacture, making them higher quality and also more expensive than those with a low value.
Wide Trail construction from Maxxis
For a few years now, many tires have had the suffix WT for "Wide Trail." This refers to tires that are optimized for use with today's wider rims. Traditional tires were developed for narrow rims and take on an overly angular shape on wide rims, meaning they do not perform optimally. Trail and enduro tires with the WT suffix are optimized for an inner rim width of around 30 millimeters, but work very well on rims with a rim width between 30 mm and 39 mm. Even though the trend in XC is also towards wider rims, these are still relatively narrow compared to trail and enduro rims. That's why Maxxis has designed its XC tires with Wide Trail technology to be optimized for an inner rim width of 30 mm, but they also work very well on rims with a width of 25 mm to 30 mm.
Seawastex nylon is made from fishing nets
Many Maxxis tires with EXO carcasses use nylon threads made from recycled material. The company Seawastex completely recycles old and defective fishing nets into nylon granulate and spins it into high-quality nylon threads that have exactly the same properties as the new material. This protects the environment and ensures that the carcasses are manufactured in a resource-saving manner. In summary, the carcass is just as important as the tire tread itself. Two-ply carcasses offer more protection against punctures. A high TPI value means that the tire adapts better to the ground, but also makes it more expensive. Those who use wide rims should opt for WT carcasses, and those who care about the environment should keep an eye out for Seawastex nylon when making a purchase.
