With the new range of Maxxis road and MTB tyres filling the shelves here at Stirling Cycles, I thought it would be a good idea to delve into the features and technologies you can expect to find in the different tyres and just what all those symbols on the side wall actually mean! Since Maxxis are one of the worlds largest tyre manufacturers (Lego are actually the largest!) there’s a lot to explain, so I’ve decided to split the posts up into a sort of mini-series, each covering a different aspect, starting with the make-up of a Maxxis tyre, then looking at the various levels of puncture protection and finally the compounds on offer.
Tyre casing comes in two options; Single-ply Casing and Downhill (DH) Casing. The former is as it sounds, a single layer of nylon wrapped between both beads. It’s light and can distort easy to conform to the terrain below. Downhill casing is made up of two layers, again wrapped from bead to bead. By doubling the layers, Maxxis can increase the protection on offer – ideal for downhill applications or rougher trail conditions.
Tubeless MTB tyres are constructed in a similar way, but include a butyl insert in the side wall to add support and increase protection of the rim to allow the tyre to run at a lower pressure. Road tubeless tyres differ slightly, the use a carbon fibre bead (explained below) with a bead cushion for security and come with a puncture protective layer directly below the tread to reduce damage from road debris. All Maxxis tubeless tyres must be used with a liquid sealant to prevent loss of air pressure.
Next up is the TPI or Threads Per Inch. This is essentially the same as the TPI on your bed sheets. The higher the TPI, the more individual threads cross through one square inch of one layer of tyre casing. Lower TPI is heavier but lends to better puncture protection and improves the cut resistance of the tyre. A higher TPI is lighter (smaller, finer strands weigh less than fewer, thicker strands) and gives the tyre a smoother and more comfortable ride by increasing the tyres suppleness. Maxxis tyres come in 27, 60, 120 and 170 TPI. Maxxis TPI ratings are the treads per inch of a single ply casing, this differs to some competitor TPI ratings like Continental whose 180 TPI on Protection Apex tyres is actually just three layers of 60 TPI placed on top of one another. This produces a heavier tyre which is not as supple as a single layer of 180 TPI thread.
Holding all that together is the tyre bead. This is the ridge that runs around the bottom of every tyre (held inside the bead cushion) and is what locks against the inside hook of a clincher rim to secure the tyre in place. Maxxis offer three different bead options; wired, foldable and carbon fibre. A wire bead is as it sounds, a solid wire running through the tyre. It’s heavy and doesn’t fold. A foldable bead is lighter, made from aramid or Kevlar fibres and can be easily folded. Finally, a carbon fibre bead increases in strength to withstand the forces of high-pressure road tyre and is also foldable.
With many rim and wheel manufacturers moving towards rims with wider profiles (30 – 35mm), Maxxis have re-engineered a number of their tyres to address the problem of an altered tyre profile (the narrower rim made the tyre profile ‘squarer’) when running tyres originally intended for rims between 20 – 25mm on today’s wider wheels. Branded as Wide-Trail (WT) Maxxis have increased the distance between the bead and altered the profile of the tyre, so when used with a wider rim, the side knobs remain in the same position as they would with a narrower rim, therefore retaining the same level of traction and feedback.
Maxxis also offer a number of tubular tyres within their road range. A tubular tyre differs from a traditional clincher tyre. Tubs incorporate a tube and tread into one, by sewing both parts together. It is then fixed to the wheel (which also differ from clincher rims) by either tub glue or tub tape.
Next time, I’ll talk about the many different puncture protection options available. But if you can’t wait til then, head over to the new Maxxis website which does a good job of explaining the range!