Michelin have finally retired their long-running "Dry" tread pattern for 2011, replacing it with the faster rolling yet more versatile Wild Race'R design. BikeRadar headed to Oak Mountain State Park near Birmingham, Alabama for a few hours of early testing. So far, the new Wild Race'R seems to maintain all the benefits of the old design – namely exceptionally traction on hardpack – but with a wider usage range and more forgiving characteristics at the limit.
Michelin have abandoned the old Dry's tight array of dash-shaped knobs in favor of hollow, square-shaped and tapered center knobs that are more widely spaced but also bridged together. There's just a hint of knob deformation when accelerating or braking – with seemingly about the same levels of rolling resistance to the old design – but far better straight-line grip in trickier conditions like loose-over-hardpack where the predecessor would sometimes skitter helplessly across the surface.
Though definitely not intended for wet conditions, the more open spacing, the 45-degree orientation of the center lugs and slightly tapered shape should clear mud much better than before – though admittedly, it would have been hard to find a tire more poorly suited to muck than the old Dry.
The biggest changes come further out at the edges, starting with paired transition knobs that fold over less under heavy load when initiating a turn for a sharper feel and less squirm. The new triangular shoulder knobs are much taller – roughly 5mm vs 3mm – and far more bolstered than before but a bit smaller in terms of surface area contact, so they're better able to bite into the ground assuming the conditions allow.
Tire profile is more squared-off than the old Dry on account of the progressively taller outer knobs but the overall shape is still gently rounded with a pronounced shoulder. As a result, quick transitions from edge-to-edge, as are commonly found at Oak Mountain, were smooth and intuitive but there's still a distinct, firm shelf you can lean hard on when laying the bike over through a corner.
Traction breaks smoothly and progressively and even comes with an audible warming, so based on this preliminary test – we're heading home with long-termers for a more proper beating – it doesn't seem like the new Wild Race'R will abruptly dump you if pushed too far.
Michelin will offer the Wild Race'R in standard and more race-oriented Advanced versions for 2011, both with nylon casings carried over from the previous generation. Standard models are built with a 60 TPI tubeless ready casing and foldable aramid bead, capped with an all-new single 63a hardness tread rubber compound.
There's a wide range of sizes, with 26in tires available in 2in (540g), 2.1in (600g) and 2.25in (735g) widths, and 29in tires in 2.1in (660g) and 2.25in (730g). Retail price is US$49.99 across the board, with the exception of the more heavily reinforced 2.25in model that adds but a single dollar to the bottom line. UK prices are still to be confirmed.
Advanced-level Wild Race'R tires will all use more supple 127 TPI nylon casings and an additional, harder 68a strip beneath just the center of the otherwise identical 63a tread cap for slightly faster rebound and lower rolling resistance but without affecting cornering grip. Tubeless-ready sizes are 26x2in (495g), 2.1in (530g) and 2.25in (580g). UST options are 26x2.1in (710g) and 2.25in (750g). All Advanced-level Wild Race'R tires will retail for $64.99.
The UST versions have airtight layers applied to the outside of the casing – essentially an extension of the tread rubber down to the bead – instead of the usual inner layer of butyl rubber. According to Michelin mountain bike tire product manager Rudy Megavand, this so-called "gumwall" construction lends a livelier feel and lower rolling resistance on account of the tread rubber's higher rebound characteristics while also improving sidewall protection.
New Protek Max inner tubes offer a unique approach to puncture protection
Michelin also showed off their new Protek Max inner tubes, which use a uniquely bumpy surface and square-shaped cross section that's claimed to be much more resistant to punctures – or more specifically, losing air pressure due to punctures – than standard inner tubes. According to Megavand, the Protek Max's bumpy surface creates a compressive force in the tube wall, in contrast to standard inner tubes where the tube walls are stretched upon inflation.
This means that small punctures which would typically enlarge with conventional stretched tubes instead tend to self-seal. In addition, the curious square cross-sectional shape is said to ease installation by maintaining the correct orientation when inserted into the tire. Michelin still equip each Protek Max tube with some sealant to finish the job, and they claim a two-fold improvement in air retention relative to other pre-sealed tubes.
The Protek Max tubes will be offered with either Presta or Schrader valves in two sizes: 700x35-47c (200g) and 26x1.4-2.125in (260g). Suggested retail price is a surprisingly reasonable $8.99.