It sure is fun getting off the beaten path on gravel bikes these days. Not only are there more gravel bike options, but there are plenty of great tires out there to suit your favorite terrain. With that, the all-new WTB Raddler 700x40c tires aim to step up the traction game for singletrack or more aggressive gravel — all while still remaining reasonably-smooth on tarmac.
WTB Raddler 700x40c Tire Features:
- More aggressive lugs than the beloved Riddler
- Single-ply 60 tpi. casing
- TCS tubeless
- Available in tan or black sidewalls
- Available with new SG2 casing/puncture protection ($10 extra – not tested)
- Widths: 40 (tested)and 44mm
- Weight: 490 grams (stated)
- MSRP: $59.95

Get “Raddler” on all terrain
I’m glad the term “rad” has made a comeback. From its heyday in the 1980’s to now, when something is rad, it’s something special. With that, one of WTB’s latest additions to their gravel tire line is the Raddler. Available in both 40 and 44mm widths, the Raddler is just that — a tire meant to get radder. I spent a few hundred miles with these tires aboard the BMC URS 01 One and came away impressed.
When it comes to selecting a proper gravel tire, you need to know your terrain and your personal limits. Not everyone is going to get their gravel bike into gnarly 4×4 roads or technical singletrack, but some will. So, I’d suggest choosing the WTB Raddler if you spend at least 60% of your time on gravel or dirt and you value traction above all else.

The little square-shaped knobs down the center are spaced closely enough to remain smooth and reasonably-fast on pavement. They splay outward when cornering and do a great job gripping everything on the tarmac. But, just don’t expect to angulate full-gas like you would on a set of pure road tires. Those front shoulder knobs do have a limit and they will let you know when you’ve pushed them too far on pavement. All-in-all, they do roll well on pavement and are on par with what I’d expect from these tires.
Now, where these little knobbies shine is on dirt and gravel. WTB has come up with quite a versatile tire with the Raddler. Just like the road, each one of those little square knobs bites into the terrain and delivers solid traction. I love how smooth these tires are on fast gravel and my body appreciates how exceptional they corner — even when the terrain starts getting loose.
The Raddler’s have also been a key part of my ability to take the BMC URS 01 into more technical XC singletrack than I have on other gravel bikes. That bike is unique in its ability to transform into a hardtail, but the Raddler’s sure grip made long, windy, singletrack descents an absolute dream. Braking and cornering are always on point.

I was able to seat these tires up pretty easily, using soapy water and the Blackburn Chamber Tubeless Floor Pump to the ENVE G23 wheels. I let them sit overnight, then placed about 4 oz of Orange Seal tubeless sealant in there and never thought about them again. Air loss is what I typically see from most gravel tires (~10 psi. after a week of hanging idle).
At 170 lbs., I kept these tires at 36/38 psi. front/rear. I could sure go lower, but I liked those pressures for road approaches and the mixture of gravel and singletrack I typically ride. Only once did I experience a full-on rim impact and nothing happened. I didn’t experience any burping or leaking throughout my time on the Raddlers. In total, I put a little over 200 miles on these tires and never experienced any punctures or issues.

As far as durability goes, these are wearing pretty well. After 200 miles of mixed riding, the only thing I’ve noticed is that a few shoulder knobs are pulling away. Nothing too terrible yet, but it’s definitely worth keeping an eye on.
Note: On the ENVE G23’s (23mm internal), these tires measure out to 41mm wide.
The Good
- Excellent traction for aggressive terrain
- Reliable tubeless setup
- Grips extremely well on loose climbs
- Pretty smooth rolling on the road
The Bad
- 60 tpi. casing does feel stiff
- A few shoulder knobs on the rear tire are starting to pull away
The Bottom Line: WTB Raddler 700x40c
When getting rad is on the menu, the new WTB Raddler 700x40c tires are some of my favorites. They deliver excellent traction on all types of gravel terrain as well as XC singletrack. I’ve been able to enjoy much more aggressive riding with the Raddler’s, which opens up more terrain on any given ride.
Buy Now: Available at JensonUSA