First Impressions: Challenge Gravel Grinder Tires

Challenge’s tubular and open tubular road tires are renowned for their supple ride. The Italian company is no stranger to the off-road set, as their Alamanzo and Strada Biancha tires have proven extremely popular with gravel riders. Challenge recently expanded their gravel offerings with the introduction of the new Gravel Grinder model.

The Gravel Grinder is available in tubular ($118.99 MSRP), open tubular ($83.99 MSRP), and clincher versions. Clinchers are offered with 60TPI ($37.99 MSRP) or 120TPI casings ($47.99 MSRP). The tubular and open tubular models are constructed by hand using non-vulcanized construction, whereas the clinchers are manufactured using conventional vulcanized construction. We recently tested the 700×38 clincher Gravel Grinder with the 120TPI casing.

Challenge GG tire

Our Gravel Grinder samples weighed 382g per-tire, which is less than the advertised weight of 402g. At the 80psi maximum pressure, the tires measured 37.5mm wide (on Whiskey’s No 7 carbon rims). The Gravel Grinders could be easily mounted (and removed) without tire levers on the aforementioned Whisky rims, as well as Mavic’s Ksyrium Elite S wheels. Both sample tires mounted without any hops or wobbles.

The Gravel Grinders’ profile can best be described as neutral. The casing lacks the peaks or squared-off edges found on some competitors’ tires. In use, this translates to a tire that handles very predictably on both paved and unpaved surfaces. For mixed-terrain use, we ran the Gravel Grinders at 55-60psi front, and 65-70psi rear. For dedicated dirt and gravel riding, we found that dropping the pressure 10psi worked well. Even at the lower pressures, tire squirm/flex wasn’t a problem (we ran the tires exclusively with inner tubes).

On pavement, Challenge’s diamond-style center tread was surprisingly smooth and quiet. We didn’t notice any excessive vibration, and the tires’ speed was on par with road tires of similar size and weight. That smooth ride also carried over to dirt and gravel. On hardpack, the low-profile tread was fast and predictable. In softer soil and gravel, the tires tracked well, and offered plenty of traction. Cornering with the Gravel Grinders was especially good. There are no dead-zones between the tires’ center and side knobs, so you can lean the bike over without experiencing one of those “Oh shi…” moments.

Challenge GG side - detail

We can’t speak to long term durability just yet, but the Gravel Grinders have held up very well during our testing. Even with 150-200 miles of paved-road commuting use, tread wear has been minimal. Challenge’s Puncture Protection Strip (PPS) has proved effective at fending off both thorns and broken glass, and the 120TPI casing has withstood Colorado’s rocky trails. If you’re looking for a durable tire that won’t slow you down on gravel or pavement, Challenge’s Gravel Grinder is definitely worth checking out.

Disclosure: Challenge provided review samples for this article, but offered no other form of compensation for this review.

First Impressions: Louis Garneau Course Helmet

Every season, the bicycle industry seems to latch onto a particular trend. Recently, companies both large and small have been touting aerodynamics as the next big thing. Whether it’s bikes, wheels, or even helmets, each manufacturer claims that their wind-slicing product will save you time and energy. With helmets, however, those savings sometimes come at the cost of ventilation and cooling. To bridge aerodynamics and ventilation, Louis Garneau developed the Course ($239.99 MSRP) helmet by using a blend of labwork and real-life conditions.


The helmet’s profile and ample vents help channel air over the rider’s head.

At first glance, the Course looks like a conventional cycling helmet. Compare Louis Garneau’s Course (with its 31 vents) to the aero offerings from Giro and Specialized, and you’re probably wondering how much aerodynamic benefit could come from such a well-ventilated helmet. According to wind tunnel testing performed by Louis Garneau, the Course can knock up to 2 minutes and 40 seconds off a 40 km time trial. Increase the distance to 180 km, and the savings bumps up to 14 minutes and 10 seconds (compared to a conventional cycling helmet).

While I may lack the facilities needed to qualify Louis Garneau’s data, I can tell you that the Course’s ventilation is excellent. The helmet’s ample airflow, combined with the X-static XT2™ padding kept me comfortable (and funk-free) during unseasonably-warm spring weather. If you have sensitive skin, or your current helmet’s straps just rub you the wrong way, you’ll definitely appreciate the Course’s ultra-soft straps (which are easy to adjust thanks to flip-lock Pro-lock dividers). To keep the helmet planted firmly on your noggin, Louis Garneau’s Spiderlock PRO II stabilizing system can be adjusted on-the-fly with one hand.


Adjusting the retention system is easy thanks to the large, indexed dial.

There’s more to the Course than just improved aerodynamics and increased ventilation. For increased protection, the helmet’s in-mold construction is reinforced with ring-shaped plastic at the base of the helmet. Additionally, an internal frame reinforces the helmet’s structure so that integrity isn’t compromised by the large vents. On May 4th, I had the unexpected misfortune of testing the Course’s safety features. I was on a trail that I’d ridden hundreds of times. One moment I was riding along, and the next I was spitting out blood and dirt. I’m still unsure of exactly what happened, but I suspect that the bike’s front wheel washed out, I overcompensated, and then went down (head-first). Thankfully, the helmet took the brunt of the impact, which resulted in a large dent in the foam, and piercing of the outer shell.


Impact damage to the author’s helmet.

The Course complies with CPSC, ASTM, and CEN safety standards, and is available in sizes small, medium, and large. My large sample helmet weighed 324g excluding the Spiderlock Vision LED light. Louis Garneau includes a second set of X-static XT pads with each helmet, as well as two CR2032 batteries for the aforementioned LED light.

Disclosure: Louis Garneau provided review samples for this article, but offered no other form of compensation for this review.

First Impressions: Crank Brothers Candy 3 Pedals

While Crank Brothers’ Candy and Eggbeater pedals may be familiar to many of GRAVELBIKE’s readers, I must admit that I’m woefully late to the party when it comes to the Calfornia-based company’s line of pedals. Recently, however, my curiosity got the best of me when I was looking for a pedal similar to Time’s ATAC, but with less side-to-slide float. Crank Brothers’ Candy pedals appeared to fulfill those requirements, so I decided to give them a try.

CB Candy 3 (03)

Candy 3 pedals in the red anodized finish (also available in blue or black).

In addition to the Candy 3 pedals ($120 MSRP) that I tested, Crank Brothers offers three other models that range in price from $60/pair (Candy 1), all the way up to $350/pair (Candy 11). The model 3 pedals feature needle and cartridge bearings (an upgrade from the cartridge/bushing combo found on the Candy 1 and 2 pedals), and cast-steel retention wings. While the materials used for the springs and bodies vary, all Candy pedals include the company’s premium brass cleats. My sample Candy 3 pedals weighed 318g/pair, with the cleats and hardware adding another 30g.

Like all Crank Brothers clipless pedals, the diminutive cleats can be configured for a 15° or 20° release. To change the release angle, one only needs to swap the cleats from left to right (and vice-versa). Unlike many of their competitors’ clipless pedals, Crank Brothers pedals do not have adjustable release tension (the company claims that their patented cleat design eliminates the need for spring tension adjustment). The stock cleats feature 6° of angular float (aka, rotation), but an optional 0°-float cleat is also available.

CB C3 - cleat

Crank Brothers cleat with the optional stainless steel Shoe Shield.

Clipping into the Candy pedals is easy thanks to the unique, rotating-wing design. In addition to conventional toe-down entry, you can scrape the cleat along the top of the pedal from either direction. I found entry to be easiest when using a combination of downward and forward motion. Once clipped in, the pedals’ bodies provided plenty of support for my cycling shoes’ soles, eliminating any rocking or unwanted flex. This added stability can affect ease of entry, however. For shoes with very deep tread, Crank Brothers includes shims which provide additional clearance between the shoes and pedals. In some rare cases, you may need to sand or trim the tread to eliminate any interference between the sole and pedal body.

As I mentioned above, my desire for reduced lateral float is what originally prompted me to try the Candy pedals. While the Crank Brothers cleats do provide a small amount of lateral movement, it’s less than the 6mm float found on Time’s ATAC pedals. Even with additional stability provided by the pedal’s body, angular float/rotation felt less restrictive than Shimano’s SPD clipless system. Although I was initially concerned with the lack of tension adjustment on the Crank Brothers pedals, I never unclipped accidentally.

CB C3 - single

The removable end caps provide easy access to the pedals’ bearings.

To keep your pedals running smoothly, Crank Brothers offers rebuild kits which include replacement seals and bearings (instructional videos can be found on the company’s website). It’s too soon to report on long-term durability, but I can tell you that the pedals did survive a crash that left me with a cracked helmet and plenty of road rash. If I do have one gripe about the Candys, it’s that they require an 8mm hex key for installation or removal. This is, however, not unique to Crank Brothers, as several other companies’ pedals eschew conventional pedal wrench/spanner flats.

Disclosure: Crank Brothers provided review samples for this article, but offered no other form of compensation for this review.