If you would have told me a couple of years ago that I was going to ever run almost 2″ wide tires and 650b wheels on a road bike of my own volition, I would have promptly laughed it off. And I’m already a proponent of never riding anything smaller than a 28mm road tire. Sure, there were rumblings around the Cannondale Slate that made waves when it was debuted with its fat road tires, but it was probably the arrival last spring of these supple, grippy Horizon tires from WTB that have made the Road Plus standard actually viable with a high quality, high performance tire for all types of road surfaces. We’ve been riding the Horizons through the fall, winter & into the spring and can comfortably say that we are now believers…
First to get it out of the way, we aren’t going to ditch fast rolling narrow or even aerodynamic tires for their own correct applications. For fast riding on smooth tarmac a more narrow tire is hard to beat. And after some time last week in the wind tunnel, we’ve seen some interesting results of how much of a difference he correct tire can have in either getting the most out of a deep section wheel or losing the benefit altogether.
But in the meantime from our EU HQ in Prague, we do a lot of mixed surface asphalt, cobblestone, gravel & dirt road riding that really benefits a wider tire that you can run at low pressures for both added comfort and the extra grip of a large & wide contact patch. That’s where the Horizon shines, and where we’ve been putting it through its paces over the last half year – from daily commutes to bikepacking adventures, and everything in between.
We first got a preview and went into the details of the Horizon last February when it was launched. The Horizon is a lightweight folding casing tire in a 47c width for 650b wheels. Ours measured up dead on at 47mm true to size, mounted to a set of 3T Discus Plus alloy wheels with a 24.5mm internal rim width. The tires use a dual compound tread with a smooth center section and a more grippy rubber for the fine chevrons that make up the shoulders.
The natural rubber sidewall Horizon gets a TCS casing that means it is tubeless compatible, but needs to be run with sealant. We rode the tires both with middleweight tubes and with Stan’s sealant installed. WTB has a cheaper, heavier non-tubeless wire-bead version of the tire. But after setting these up tubeless and with such an improvement in ride we wouldn’t be likely to even give those a try.
WTB claims a weight of 515g, with our set coming in just a tad heavier at 520g after having seen a little time in the dirt. The Horizon retails for $68 and has recently been joined by a sibling with the exact same construction (and pricing) called the Byway that just adds shoulder knobs for more riding off-road in loose conditions.
So what swayed us about riding these tires? To be fair we are kind happy to ride any good quality wide road tire in the dirt, and most do surprisingly well. Coming from a mountain bike background, a bit of good bike handling goes a long way and drifting slick tires through turns can be a blast as long as it is expected. But what first really sold me personally on these tires was their unexpected grip riding through the winter. I had been commuting through snow & ice on the Exploro above (yeah, I know that is a nutso commuter; different story, coming soon) riding daily over an ice covered spiral ramp here in Prague without a care in the world. Then a warm(ish) rainy day made me pull out my commuter with full fenders and 28mm tires that I have always been happy with. I almost crashed twice on the way to work, trying to guess what was going wrong. Same thing happened on the ride home, so I grabbed the Horizon-equipped Exploro and gave it another go. No problems. The low pressure, wide contact patch, and subtle tread just hooked up on the icy path littered with bits of gravel/grit that the wide 700c road tire didn’t even come close to sticking to.
Sure that really only applied to a very specific condition, but it clued me into how much extra grip these tires had been hiding. Since that winter I have transitioned the same grip in loose over hardpack performance to a number of other surfaces – loose gravel roads, dirt roads with the occasional loose bits, and unexpected washed out sand & gravel in asphalt corners. Every time the Horizons have offered more grip than expected.
Our other testers here backed me up on the idea centered around the ability to run the Horizons at crazy low pressures without tubes. On 25mm road tires at 100psi it is hard to quantifiably perceive the difference of going tubeless or not. Sure, the lab data show clear reductions in rolling resistance and if you pay close attention riding the same routes back to back, with and without tubes you can feel it. But here with Road Plus it truly is a whole other world. With tubes you aren’t going to make it very long at 25-30psi without a rash of pinch flats, but with the Horizons set up tubeless we spent months at those low pressure without incident, even over 500km of loaded bikepack touring over hill and gravel dale. Tubeless road is simply better for this type of riding off the beaten track.
The 47mm Horizons are very much a mountain biker’s road tire, no surprise coming from an off-road focused company like WTB. If like us you are the type of rider who gets back from road rides covered in mud, or just feels the need to ride off on any dirt or gravel track that you pass, the 650 Road Plus concept has some merit. While previous tires like the once that came stock on the Slate were underwhelming to us, the supple WTB casing has seemed to offer a just right balance of low pressure grip and rough road comfort that has held up so far to our gravel road and dirt trail abuse. And it’s been convincing enough that we’ll keep looking for a chance to stick Road Plus 650b tires into whatever frames we have that will fit them. We’ll look forward to getting the Byways dirty too.