WTB Nano 700x40C Gravel Tire Review

Disclaimer: This post contains affiliate links, through which we earn a commission.

As I've written at length in a previous blog post, tire choice is critical when planning for a gravel ride. Not only does the correct tire choice play a role in the comfort and handling of the bike, it also dictates the tire pressure that can be achieved with a particular set-up. 

Tire choice is in large part a fairly individualized preference and the type of terrain you ride on most frequently will certainly influence the type of tire you require. Loose, rocky gravel single tracks will require a completely different tire when compared to a smooth hardpack gravel road. There are, of course, a few trade-offs that applies as you cater your tires for specific uses.  While 32-35mm tires with a smooth rolling surface will fly along over easy-going surfaces, it might not get you (comfortably) through a technical riding section along single trails. The opposite side of this logic also applies, in that a chunky 42+mm tire can easily scale various gravel surfaces, but in turn will slow you down when it comes to paved roads or smoother gravel roads. 

Shortly after I received my 3T Exploro gravel bike (review here), I had to consider what tires would work best for the kind of riding I do most often. The 3T Exploro came fitted with the WTB 37mm Riddler tires as the stock option. While the original tires might have been great for the regular gravel roads in my area, I knew that I would frequently venture into a nearby state park for my gravel riding fix. The state park includes a much larger selection of fire roads, as well as both wide and narrow trails and most importantly a few steep climbs covered with loose gravel and leaves. I needed a tire that could easily roll over the paved roads on route to the park, but at the same time also master the more technical sections that encountered throughout the park.  

Swapping out the Riddlers, I fitted the WTB 40mm Nano tires to my bike and have been extremely pleased with the decision. Let’s take a look at some of the key take-aways that I’ve encountered during the last 4 months (~1000 miles/1600km) while riding the WTB Nanos.

Tech Specs:

No review will be complete without a quick look at some of the technical specs that you will find with the WTB Nano tires. I’ll focus my review on the “TCS Light/Fast Rolling (tanwall)” version, but you can find a detailed spec breakdown for all Nano variations (4 in total) on WTB’s website.  As the aforementioned name suggests, I opted to go with a tanwall version of the Nano 40mm tire. The claimed weight for this version is stated at 497g and comes in slightly lighter when compared to the non-tanwall version (530g), which offers some more sidewall protection.  I specifically wanted to run these tires as a tubeless set-up and therefore did not opt to go for the lighter “Race Tube-Type” version that does requires an inner tube.  

Minimum achievable tire pressure was another consideration in regard to picking the tubeless version over the tubed version. Because my regular riding terrain includes some technical sections with minor rocks and tree roots, I need the ability to push pressure as low as possible when necessary. The stated pressure range for the tubeless version is listed at 25-50psi, while the tubed version of the tire has a range of 40-70psi. Having experimented a great deal with the tire pressures, I have come to find that 35psi is the sweet spot for the more technical terrain, while a pressure of 40psi gives me a good rolling resistance on days when I only ride on regular hardpack gravel roads. While these numbers work well for my setup, your bike design and body weight will, of course, alter the required tire pressure. 

Paved Roads vs Gravel Roads:

I was pleasantly surprised at how well the Nanos performed on paved roads. After riding with the narrower WTB Riddler tires for a few rides before switching over to the Nanos, I could almost not tell that there was any significant additional rolling resistance. In fact, the Nanos even excelled on the paved roads in comparison to the Riddlers. The fast rolling is due in part to the raised center tread, which gives a very fast profile, with minimal rolling resistance. They are, however, not the same as a pure road tire and you will definitely feel a slowdown when compared to other tires that were designed for road use. The tire pressure is a deciding factor when it comes to the paved road experience. If you run them too soft, they will feel sluggish, as the side knob pattern on the tire comes into greater contact with the road. 

Because the intended use for these tires is not paved roads, they truly come into their element on the dirt roads, particularly dry, hardpack surfaces. The company’s website claims that these tires are “FAAAASSSTT!!!!!” and I will 100% attest to this statement. On a regular gravel road, you can certainly feel what they are capable of. The praise for these tires doesn’t stop with pure straight-line performance. The very thing that appealed most to me when opting to switch over to these tires was their ability to handle more rugged terrain. I needed something that could get me through rides with lots of loose gravel and steep hills, without any tire slip – something that I experienced a few times with the Riddlers. The thread pattern layout of the Nano tires provides excellent grip. The correct application of force through your pedal stroke is, of course, still important as a jerky pedal stroke will result in some tire slip when going up the steeper climbs.  

_CBP9827.jpg

Single-track trails & Extreme Cornering:

In making my tire selection, I also considered the ability to corner down steep descents with stability.  Over more technical off-road terrain, the Nano 40mm tires did not disappoint. The mountain biking history of this tire definitely shines through when it comes to tougher terrain. The legacy predecessor to the Nano 40mm gravel tire can be found in the Nano mountain bike tire. The gravel version comes with slightly shorter knobs, but it certainly retains its heritage, with the ability to withstand trails and more chunky off-road surfaces very well. The side knob pattern helps to provide a great deal of confidence when leaning into corners and also gives excellent traction when braking hard. 

Having tested these tires extensively throughout the more technical sections, the extra grip in the corners especially blew me away. In the past, I've used a mountain bike with 1.95inch (50mm) tires over many of the same technical sections, but these 40mm Nano tires still inspire more confidence around the sharp and rocky bends. When it comes to the technical off-road, I can certainly give these tires my sign of approval. 

_CBP9832.jpg

Dry vs Wet Conditions:

On WTB’s website, they state the intended conditions for use as “Hardpack / Dirt / Gravel.” The keyword in that statement is hardpack. These tires perform significantly differently under wet and dry conditions. On dry surfaces, the Nanos do a great job, but the same cannot be said for wet and/or muddy conditions. I've experienced a noticeable amount of additional rolling resistance on days when the trails and gravel paths were wet and muddy. As stated above, the tires certainly hold the ability to be extremely fast along a dry and hardpack surfaces, but the side knobs on the thread pattern certainly add some resistance when the ground is soft from any moisture. If you are planning on doing a gravel race in which you expect to encounter a great deal of mud, then you might want to look elsewhere for a tire that would be better suited for wet and muddy conditions. 

Wrap-Up:

Other than the drawback of slower performance in wet conditions I really can’t find that much wrong with the WTB 40mm Nano tires. They have been a joy to ride and truly provide a peace of mind that comes with knowing that no matter what unexpected road surface awaits along your route, you will be able to handle it with these tires. If you are in the market for a 700c gravel tire, then the WTB Nano 40mm tire is a great choice. Whether it be hardpack gravel roads, loose gravel or single-track trails, the Nanos will provide the perfect balance of speed and handling to make for an enjoyable ride.

Check out the video for this blog post here! Let us know in the comments section what you like most about your Nano tires or why you think there are other tires that can do a better job. Thanks for reading!

-Wiehan




Sign up to receive news and updates!

* indicates required
Mountain Road Newsletter