When I reviewed Teravail’s Rampart road-plus tires last summer, I didn’t anticipate that they would become my go-to tire for mixed surface riding. The 650B x 47 tires’ ample volume offered plenty of flotation (and comfort), but with much of my commute now taking place in the dark, I found myself wanting more traction and control than the Ramparts’ minimal tread could provide. As luck would have it, however, Teravail began offering their Cannonball gravel tire in 650B sizes, so I decided it was time to give them a try.
Designed for gravel racing, the Cannonball features a directional, tightly spaced center tread pattern. According to Teravail, the tire’s tread pattern is optimized specifically for gravel riding, and helps shed dirt and debris. Like the company’s Rampart model, the Cannonball is available in 650B and 700C sizes, in widths from 35 to 47 millimeters (depending on size). Both the durable and light/supple casing options are tubeless compatible, and tan-sidewall versions are available in select sizes. Prices range from $40 (650B x 40, light/supple casing) to $65 (650B x 47, durable casing).
Teravail’s target weight for a light/supple 650B x 47 Cannonball is 515 grams, and my sample tires averaged 513 grams. Mounted on Zipp 303 Firecrest carbon rims (21 mm internal width) and inflated to 50 psi, the tan-sidewall Cannonballs measured 48 mm wide at the casing, and 49.5 mm knob-to-knob. Like the Ramparts that I previously tested, the Cannonballs set up tubeless using only a floor pump. Unlike some companies’ tires with lightweight casings, I didn’t notice any weeping after injecting each tire with 2.5 ounces of Orange Seal Endurance Formula sealant.
The first ride on new tires is always interesting, and my shakedown cruise with the Cannonballs was no exception. The tires rolled smoothly, but they were anything but silent. The noise, however, wasn’t the result of friction between the tread and pavement. Nope, it was the sound of hundreds of tiny pebbles flinging off the tires and ricocheting against my Vaya’s metal fenders. As the tires’ mould release wore off, however, the pinging subsided, and the bike’s quiet ride returned. A quick gravel-path detour confirmed the Cannonballs’ increased traction compared to the well-worn Ramparts that they replaced.
After spending many years, and thousands of miles commuting over the same route, I’ve developed a good feel for how different tires can affect riding speed. Using the Ramparts’ pressure as a baseline (23-25 psi front, 28-30 psi rear), the Cannonballs felt sluggish on pavement and hard-pack dirt roads. “Cannonball and Rampart tires share the same casing, so the Light/Supple constructions should have comparable sidewall stiffness,” offered Teravail’s Zane Bushey. “The Cannonball is a bit stiffer, though, as the tread (pattern) is thicker on the outer shoulder of the tire. The tread is also much deeper, and while the irregular surface area is great for providing traction in loose conditions, it’s inherently slower rolling on smooth surfaces.”
Bumping the Cannonballs’ pressure up to 30 psi in front and 35 psi in back, made a noticeable improvement in the tires’ performance; both on- and off-road. Braking and cornering in loose dirt and gravel proved to be extremely predictable. I was able to detect a very slight difference in traction when transitioning between the smaller shoulder tread elements and the side knobs, but only when I really leaned the bike over. Unlike some tires with widely spaced side knobs, though, the Teravails didn’t exhibit any tread squirm during hard, fast turns on pavement. And at the risk of angering the tire gods, I’m happy to report that Cannonballs were puncture-free during my four-month test period. Tread life was also better than expected, with the front tire showing virtually no wear to the shoulder and side knobs.
While I still prefer Teravail’s lighter Rampart for pavement and hardpack dirt roads, the Cannonball has proven itself to be a solid performer in loose, unpredictable conditions. The only area where the tire suffers is in very deep (fine) gravel, but the same can be said for other, similarly sized tires. And if you haven’t yet made the switch to tubeless, the Teravails’ effortless setup may just get you to ditch inner tubes altogether.
Disclosure: Teravail provided review samples for this article, but offered no other form of compensation in exchange for editorial coverage.