WTB recently launched a new tread combining elements of their successful small-knob Riddler gravel tire with taller blocky edge knobs for more cornering traction on loose surfaces. “A radder version of our famed Riddler tread pattern,” is how WTB states it.
The tires use the TCS Light/Fast Rolling casing, a single-ply 60 tpi casing WTB uses for all gravel and cyclocross tires throughout its line. Interestingly, while the Riddler comes in 37mm and 45mm sizes, the Raddler’s size range is narrower with 40mm and 44mm versions.
The size and number of side knobs of the Raddler are the greatest within this category for WTB.
The 3mm-tall blocky knobs border the outer edge of the tread, yielding a squared-off tread. The small center knobs are in the same tight configuration, but at 1.5mm, they are slightly taller than the original Riddler. They roll quite well with minimal buzz, but offer better mileage on hard surfaces.
In our experience, WTB tire dimensions run nearly true to size. The Raddler 44 and 40 both ran slightly smaller than labeled when I mounted them on a 25mm internal width rim. I suspected this might be the case with bead-to-bead casing measurements out-of-the-box that were a bit lower than expected for the labeled sizes.
Tire design and manufacturing are more complicated than you may think and WTB advised us to allow the tires to stretch and settle before making a final assessment. We all know that a tire is easier to mount and dismount after stretching on the rim for a day or two. I took the width measurements several days after mounting them, pumped up to 40 psi, higher pressure than I would typically ride a 40 or 44mm tire.
The Raddler 40 has a casing measurement 39mm wide with a tread width of 40mm. The Raddler 44 has 43mm casing width, wider than tread width in this case.
Our samples of the two sizes have remarkably similar weight, 525 grams for each of the Raddler 44 samples, and 515-522 grams for the Raddler 40 samples.
Given the similar weight of the two widths, I opted for the wider of the two for our initial rides. The tread footprint is of the two sizes is similar. The wider tire has essentially the same tread width as the narrower version, so the former puts more of the tread on the ground. The rear tire was set up with a CushCore gravel/CX insert that we favorably reviewed.
This allowed insanely low pressures for the tire size, improving smoothness, traction and handling. The CushCore provided cornering confidence despite pressure in the teens.
I rode the front Raddler 44 tubeless with 20-24psi depending on conditions.
The small, closely packed center knobs roll seamlessly on pavement, fast and no buzz-similar to a file tread. Though the wide casing puts the peripheral knobs in closer contact, there is still a mildly-rounded tread profile keeping the ride smooth when riding straight ahead. Cornering immediately engages the large block side knobs. You can hear them, and feel just a hint of squirm, but still feel planted since the knobs are broad and well supported.
On hardpack, the Raddler 44s are fast and smooth. On a loose surface, as we’re now experiencing with the short California winter this year, the small teeth of the center tread offer enough traction in loam and damp dirt. When it gets dusty and loose, I think the center tread will slip on steep climbs, as I’ve experienced with the Riddler. The Raddler 44 has the advantage of the larger peripheral knobs engaging on irregular surfaces, so I expect it to perform well on most gravel and mixed terrain adventures.
The Raddler is available with a tan or black casing for style. The catalog lists the black sidewall as 12-15 grams heavier than the tanwall. I did not verify this since our samples for each size were the same color.
WTB Raddler 44 Gravel Tire Specs:
Casing: TCS Light/Fast Rolling 60 tpi
Width: Bead-to-bead: 108mm, casing width 43mm/tread width 40.5mm (on 25mm internal width rim @ 40 psi)
Weight: 525 grams (tanwall)
WTB Raddler 40 Gravel Tire Specs:
Casing: TCS Light/Fast Rolling 60 tpi
Width: Bead-to-bead: 96mm, casing width 39mm/tread width 40mm (on 25mm internal width rim @ 40 psi)
Weight: 518 grams (blackwall)
More info: wtb.com