Before we go any farther, let’s be clear about what this tire is, and what it isn’t.
First, it’s not a purebred cross country tire. It’s too wide and too heavy.
Second, it’s not an apples-to-apples replacement for a meaty, knobby tire like, for example, a High Roller II. The HR II has a bunch of big paddle-y knobs that do a really good job of slowing you down. The Riddler doesn’t have those, and so, unsurprisingly, doesn’t do a particularly good job of slowing you down.
What the Riddler does have are pretty good cornering knobs mounted on a relatively wide casing that also rolls really quickly. For a rear tire, this is an attractive option for a lot of people – you can still go around a corner pretty quickly, but the tire will carry a lot more speed on flatter bits of trail where a fully knobbed tire isn’t necessary.
(Note: I only rode the Riddler as a rear tire. You could certainly run in it on the front as well, but personally I think that’d give up too much ground in the braking department. Also, most of my time on the Riddler was in fairly dry conditions in Montana: some hardpack, some duff, a little bit of gravelly stuff, but not much in the way of sand.)
Now, there are obviously some trade offs.
First, I think I’ve dropped enough hints already that these things don’t do all that much when you hit the brakes. More accurately, they skid and slide around all over the place. Those little center knobs do their best to slow you down, but if you’re used to a knobbier tire, these will feel pretty skittery and loose. But the more uniformly hard packed the trail was, the less I noticed this to be a problem.
Second, climbing. Again, on reasonably hard packed trails, they do pretty well; the little knobs dig in a bit better than I was expecting. But on steep, loose climbs, there’s still no substitute for big blocky paddles like on a High Roller.
In return for accepting those tradeoffs, what you get is a really fast rolling tire.
The tire I had mounted up prior to the Riddler was a Continental Trail King, and while that’s certainly not a particularly fast rolling tire, just swapping to the Riddler on the rear made a very noticeable difference in rolling speed (even with a Trail King still mounted up in the front).
It’s tough to quantify how much faster it is, but it’s a far more noticeable difference than any tire swap I’ve made in recent memory, including tires like a Schwalbe Hans Dampf, a Continental Trail King, or a Maxxis HR II. This shouldn’t be too surprising since those are all pretty knobby tires, but the Riddler rolls a lot faster than any of those.
But it’s the Riddler’s cornering that probably has most people interested.
Most XC tires roll fast but corner like junk, and the Riddler was designed to solve that little conundrum. And indeed, it does corner pretty well. It’s an interesting feeling, because the tire is super loose and drifty until you really lean it over. And then, all of a sudden, it hooks up.
The side knobs aren’t quite as tall as some other knobby tires out there, and they’re relatively closely spaced. They are also a bit angled, which I’ve been trying to wrap my head around. It seems that those angled knobs present a bit more braking edge to help maintain traction while on the brakes and leaned over. Those angles seem like they potentially give up a little bit of lateral grip, though.
Here’s a picture with a Schwalbe Hans Dampf 2.35”, the Riddler 2.4″, and a Maxxis High Roller II 2.4.” As you can see, the side knobs aren’t quite as large as on the Hans Dampf or the HR II. It’s also worth noting that the side knobs on the Riddler are smaller than a Specialized Slaughter, which is more of a comparable aggressive semi-slick tire.
On the trail, the Riddler’s side knobs yield fairly solid, predictable cornering traction. They’re not as locked in on corners as something like a High Roller II, but all things considered, they corner pretty damn well.
Compared to a more knobby tire, the Riddler seemed to do a bit better on harder-packed corners, where some tires feel squirmy. I’m chalking that up to the slightly smaller, more tightly spaced side knobs that offer more support when they can’t really sink in.
As I noted above, the Riddler bears a lot of similarity to the Specialized Slaughter, but unfortunately I don’t have any time on the Slaughter to really comment on that comparison. I’d venture a guess that the Riddler would roll a bit faster (due to smaller, more tightly-spaced center knobs), but not corner quite as hard in soft dirt (since the Slaughter has larger side knobs).
On my home trails, I really liked the Riddler. It doesn’t give up too much ground in the corners, and I definitely appreciate having a lot less rolling resistance. Since these are trails that I know really well, having a bit less stopping power was manageable, and I’ve been ok with the tradeoff.
Riding new trails that I hadn’t been on before, the Riddler occasionally added an extra bit of excitement to the ride. Last minute panic braking when the trail took an unexpected turn was certainly less controlled than on a knobbier tire. I had to either come into corners a lot more cautiously, or deal with hacking the bike sideways so that I could get the side knobs engaged.
Perhaps the most accurate way to describe the Riddler is that it’s less forgiving. It can be cornered hard, which encourages you to enter corners at higher speeds. But if you mis-judge the corner, the lack of center knobs on the Riddler means that it’s a lot harder to correct your mistakes and you’re going to have to deal with some loose driftyness while you get back on your line.
On the plus side, it’s kinda fun that when the rear end gets all loose, you can always just lean the bike over and engage those side knobs to regain a bit of control.
I don’t have enough time on the Riddler to really accurately assess long term durability, but so far so good. I’ve spent time on other WTB tires with the same “TCS Tough” casing, and I’ve had good luck with them.
The tread on the Riddler seems to be wearing about average. I haven’t torn any knobs off, and they seem to be rounding off at a rate that’s in line with most other tires. Judging from my past experiences with other WTB tires that have the same compound, I’m not expecting any untoward deterioration out of the Riddler, although I expect that lots of hard, drifty riding will likely take its toll on those little center knobs.
I’ve heard about some issues with flats on semi-slick tires, presumably because of the lack of rubber down the centerline of the tread. I was running the Riddler at my “normal” pressure, which is between 28-30psi, set up tubeless.
I didn’t have any issues with flats or burping in my time on the Riddler. If that is an issue you’re concerned about when choosing a semi-slick, I’d venture a guess that the Riddler might work a bit better than other options due to the beefier casing.
The WTB Riddler probably isn’t a tire I’d recommend to a beginner or someone who isn’t reasonably comfortable with significant lean angles in corners. It’s also not a tire I’d pick for riding super steep trail, or in loose soil where solid braking performance is important, or for places where you have to deal with a lot of mud.
But if you’re pretty comfortable on a bike and you’re looking for a way to cut down on rolling resistance without giving up too much ground in the cornering department, the Riddler is a great option. Particularly for day-to-day riding on trails that I know well, I’m a big fan of how this tire makes the climbs and flat bits easier while still retaining solid cornering performance.