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Pearl Izumi Syncro Fuel

By Tom Demerly

Pearli Izumi's Syncro Fuel is a pleasant surprise for a great multi-purpose runner for the roads we really run most often.

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Tucson is the perfect place for testing running shoes. We’ve got paved roads, flat packed-earth trails and some of the gnarliest technical trails on earth.  I have my favorite shoe for each.

My new packed trail favorite is Pearl Izumi’s Syncro Fuel . The Syncro Fuel is a “tweener” shoe that isn’t a Brooks Cascadia, Salomon or Montrail technical off road shoe. It isn’t at home on the craggy, broken rock, off angle ankle-twisters. It’s overkill for a tempo run on pavement. It is the perfect “park shoe”, a niche that probably describes the way most people run trails. This is a road shoe built for the street and hard packed trails that are mostly flat with good footing.

Pearl Izumi is, most prominently, an American brand of a Japanese company. Started in Tokyo and named for clear waters where pearls are harvested the company came out of its shell when “The Boulder Crew” of Davis Phinney, Andy Hampsten, Stan Mavis and Hugh Walton bought the trademark from Spyder Ski Company in the early 1980’s. You know Hampsten and Phinney are fathers of the American bike racing, especially in Europe. Phinney was the first American to win a stage in the Tour de France. Hampsten was the first American to win the Giro d’ Italia. The company headquartered in Boulder, Colorado as one of the original outdoor manufacturers that shaped Boulder as the outdoor endurance capital of the U.S.

With conventional drop and geometry the Syncro Fuel will suit the middle 80% of runners accustomed to conventional shoe geometries.

Pearl Izumi was known in the U.S. firstly for their cycling clothes. Their technical approach to fabric, pattern and fit lead the U.S. cycling world into the technical apparel age. Before Pearl Izumi it was wool jerseys and leather chamois.  In 2005 the brand went off the rails when Nautilus Fitness acquired Pearl Izumi and added it to their stable of fitness brands. The brand and distribution were diluted. Nautilus spun Pearl Izumi off in 2008 returning it to its earliest roots in Japan when Shimano bought Pearl. Pearl Izumi stumbled again when an ad campaign that championed their early running shoes featured the catch phrase “We Are Not Joggers” that many bloggers characterized as elitist.

Despite marketing and ownership speed bumps Pearl Izumi has consistently produced solid product in many of their categories. The Syncro Fuel is an example.

The significant curvature or "rocker" of the forefoot section makes for smooth transitions and nice push off. You don't spend energy deforming the shape of the forefoot of the shoe.

You can tell Pearl Izumi designs were influenced by the beautifully groomed trails around Boulder when you run in the Syncro Fuel. The magic of this shoe is the ride: There is just enough stability, just enough cushioning. Many shoes beef up guidance, traction, weather proofing and shock absorption for marketing purposes or the rare super-craggy off angle back country user. They become low top, light weight hiking shoes. They put on weight and lose “feel”. They aren’t running shoes anymore. That shoe has its place but not on the foot of most park-runners. There is a trail version of the Syncro Fuel, but this road version has all the features we needed to take the shoe off-pavement in the park- and it isn’t overkill on the road since it was born a road shoe.

Forefoot details include a demi-toe cap and flex-grooves in the forefoot so the shoe easily conforms over changing run styles and tempos.

The Syncro Fuel lands somewhere between a road shoe and a trail shoe by retaining the cushy midsole but building an upper that resists dust and dirt intrusion and having a lacing system and saddle area that really straps you in for the ride. Add a modest toe bumper and you have everything you need to run in the park off the pavement. They are like a nice looking Jeep Grand Cherokee with a cool stereo but no lift kit or monster mudders.

The first time you run in the Pearl Izumi Syncro Fuel you immediately notice the fantastic forefoot cushioning. It’s a luxury ride. The forefoot has generous cushion and is built stable enough to hit the ground and come up relatively square. There is also a lot of rocker in the forefoot, easing transition off the toe. Pearl Izumi uses Skydex to absorb shock in the heel. Skydex is a patented material tailor made for specific applications. Common uses of Skydex are blast mitigation for military helmets and blast reduction and shock absorption in the floor of armored vehicles. The Skydex configuration for the Pearl Izumi Syncro Fuel provides not only great cushioning but fantastic stability as well. Both the Skydex heel and the cushy forefoot contribute to the luxury ride.

The unique Skydex crash pad is a staple in military applications including the seats of the light scout vehicle on the right and in the ballistic helmets of the operators inside.

Stability is also managed with the Pearl Izumi Syncro Stability Frame in the forefoot. This is a plastic exo-skeleton affair we’re used to seeing in many running brands such as Asics with their “Propulsion Trusstic”. These accessories on the midfoot do seem to resist twisting forces and provide guidance for a shoe. The Syncro Stability Frame extends well up the medial side of the shoe into the heel, offering a nice level of guidance to manage the shock absorption of the opposing Skydex crash pad on the lateral heel. At the back of the heel there is a clear polymer buttress that shores up the heel counter.

A hard polymer stability component/roll bar adds structure to the cushy medial heel. It's just enough ride control.

The outsole on this shoe has enough carbon rubber on it to make it last. Push-off is assisted by a set of grooves tooled into the midsole and outsole called, originally enough, “Forefoot Flex Grooves”.

Geometry of the shoe is a 10 millimeter drop from the 23 millimeter heel down to the 13 millimeter forefoot, a nice ramp and geometry. While designed as a road shoe, if you consider this shoe as a part time groomed trail runner (albeit a light duty one) this shoe runs light, 11.2 ounces measured weight compared to the 14.0 ounce weight of a full feature Salomon XA Pro 3D Ultra GTX and 10.4 ounces for an INOV-8 Roclite 295 at the opposite end of the weight spectrum.

The uppers are beautifully done inside and out. The saddle area takes a cue from Montrail and uses webbing as eyelets with a very wide lacing radius that covers a lot of the top of your foot. The advantage is the laces really control the volume through the forefoot, dialing in fit as you lace the shoes. The top two eyelets use a more conventional eyelet design. Fabric on the uppers resists sand and dust intrusion, a boon here in Arizona.

The interior is a seamless rear ¾ riding over a dual density removal insole. The seamless rear end of the shoe liner gives way to amore ventilated forefoot in the toe box keeping the shoe reasonably cool.

Almost the entire interior of the shoe is seamless for a delightful feel even with bare feet. The lining and outer resist intrusion of dust sand and debris.

The two overriding impressions running in the Pearl Izumi Syncro are cushion and ride. It’s a “floaty” shoe with a lightly armored uppers that strikes a nice balance between the ironclad off road shoes and the light weight, uber ventilated road shoes.

If your running on crushed stone or hard packed dirt park trails I doubt you’ll find a better ride or a more appropriately built upper. This is a great “park” shoe for the type of tame trail running most of us do most of the time. For the few speed bumps Pearl Izumi hit on the way to coming up with this shoe I’ll say it was worth it as this leads the narrow category of civilized trail shoes quite nicely.

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Pearli Izumi did a nice job of nailing a niche-of-a-niche with their light trail use/road shoe Pearl Izumi Syncro Fuel, a great road and groomed trail runner shoe for moderate conditions.