Monday, November 25, 2013

Skechers GoRun Ultra: From the drawing board to the display shelf

Skechers GoRun Ultra, fresh off finishing the grueling Hardrock 100.
Skechers GoRun Ultra, midsole-outsole wear after Hardrock 100.

Background and Overview
For over a year and half now I've been working closely with the Skechers Performance Division to wear test, critique and now develop high quality running shoes for road and trail use.  

Disclaimer: I am a potential 2014 Skechers Team member but haven't been compensated in the past in any way by the Skechers Performance Division other than getting to keep the shoes I test. However, I did receive a small monetary compensation for the great deal of insight (time and energy) I provided for the design and function of the GoRun Ultra (far above and beyond what a typical wear-tester would provide). I will stress that as a long time runner (over 22 years) I take my training and racing seriously and if I felt that the Skechers Performance line wasn't up to the task I honestly wouldn't waste my and your time with their products. I really believe the Skechers Performance Division is very serious about creating a line of products that serious runners will like.

Over the summer of 2012, I pitched an idea for a new, high cushion, hybrid road-trail running shoe to the Skechers Performance Division and low and behold I wasn’t the only one thinking the same thoughts as some other Skechers wear testers also made similar, independent, suggestions. The Skechers Performance Division thought it was a great idea for a lot of reasons and so work began in earnest with some of the first prototypes arriving on my door step by mid December. My proposal had ulterior motives, as I wanted to have a shoe that I'd be confident wearing at the grueling Hardrock 100 this past July and at the same time a shoe that would be equally home on long, paved, road runs. Over the next year, after many trials, tribulations and prototypes the GoRun Ultra (GRU) has finally come to fruition! I'm extremely happy to report that this shoe has surpassed even my wildest expectations ( I finished 15th overall with an over 2 hour personal best at Hardrock). 

The key feature of the extremely light, 4mm heel-to-toe drop GRU is that the very slightly concave midsole/outsole is about 1.5 times thicker than a conventional running shoe and significantly softer and spongy yet still retains some "pop" (toe spring stiffness). The end result is a soft yet still springy midsole that absorbs and deflects anything you run over like a fat-tire mountain bike (my other hobby)! The midsole/outsole really smoothes out your run on irregular terrain considerably! At the same time the soft lugged outsole performs quite well in every trail condition and surface I tested it in; from slick southern limestone, roots and mud to the screen fields and slippery high alpine tundra of the San Juan Mountains in Colorado and everything in between. Trust me I really put this shoe through the wringer! I had too. I wanted a shoe that could go the distance at Hardrock without having to worry about changing out shoes. I’m the kind of ultra runner who likes to put on their socks and shoes before the race and not touch anything until after the race. I rarely change socks and almost never change shoes during a race, so I expected the GRU to be able to fit into my race routine as well.

A nice aspect of the GRU is that since it was built as a hybrid road-trail running shoe the lugs are not overly aggressive and are well distributed along the relatively soft outsole. Therefore the GRU feels right at home on the roads; it’s very smooth and natural; the slightly concave and flexible last make this a very quiet running shoe! Even if you're not an ultrarunner, the great thing about the GRU is that it also makes a great recovery shoe since it's so cushy and light. The GRU is a great choice for the day after a tough run or anytime you want a bit more protection underfoot.  

Overall, while the GRU still needs a little work here and there with respect to durability and stability it did perform flawlessly not only during my intensive multi-week elevation gain focused training but also during some pre-race peak bagging and altitude acclimatization sessions and in the race itself. At a relatively low price point compared to other high cushioned, performance oriented hybrid trail-road shoes the GRU is a true bargain and worth the investment.
More Details

Some vital statistics of the Skechers GoRun Ultra:
      Weight: 9.1 oz (M9), 7.1 oz (W6)
      Stack Heights:
o   Forefoot =  23.0 mm
o   Midfoot = 29.0 mm
o   Heel = 27.0 mm
o   Net Drop = 4.0mm
o   Sockliner = 3-7 mm (tapers from 7mm at heel to 3mm at forefoot)
         Nets (footprint width):
o   Forefoot = 114 mm
o   Midfoot = 71 mm
o   Heel = 86 mm
o   Midsole = 41 C
o   Outsole = 60 C

The Upper
From the onset of the GRU project I insisted that the net volume of the upper and heel collar be enough to accommodate my Superfeet arch support insoles (with the included sock liner removed). I also lobbied to ensure there would be enough room in the toe box for proper toe splay. While the GRU is no Altra Running Shoe with its awesome anatomical fit, the GRU isn’t bad; certainly a lot roomier than a lot of shoes I’ve worn over the years and even a big improvement over some of the early Skechers GO line I wear tested. I found the upper to be reasonably breathable even during the hottest summer months. The upper also seemed to drain reasonably well after many soaking from mud, creek crossings and the occasional monsoon thunderstorm. All through my months of training and testing the GRU I had zero blisters or chaffing issues. 

The Midsole-Outsole
The midsole-outsole of the GRU uses a unique combination of extremely soft “Resalyte” in the midsole (41 C) and more firm “Resagrip” shell in the outsole (60 C). Resalyte  is a very lightweight, injection-molded compound with memory retention and Resagrip is similar to Resalyte but has as stickier feel.  In my experience the midsole felt very cushy yet still had a bit of spring or “pop” to it much like my experience with the Hoka Bondi B or Hoka Stinson Evo. The GRU, like the entire GO performance line, has a slightly concave bottom that is supposed to promote more of a mid-foot strike zone and more fluid stride according to Skechers.  The curve is hardly noticeable on use; from the heel which is 27.0 mm thick the curve peaks at 29.0 mm thickness at the midfoot and then tapers off to 23.0 mm thick at the forefoot.  The end result is that this shoe has 4mm of drop from heel to forefoot.  What really sets the GoRun Ultra apart from the Hoka line is that the midsole is far more flexible.  

**UPDATED 27-NOV-2013**
Unlike the Hoka line which features a bathtub like midsole that wraps around the foot (particularly around the heel) the GRU midsole does not have this recessed type fit. Good or bad, the recessed bathtub fit of the Hoka line adds a considerable amount of bulk to the shoe that the GRU lacks. My own personal experience from running in Hokas for several years is that the extra bulk didn't seem to contribute much to the overall function, stability or cushioning of the shoe, rather they seemed unnecessarily clunky and unorthodox on the trails. However, I think the GRU could stand to benefit from making use of a slightly recessed midsole fit to some degree to add slightly more stability to the shoe. By the same token, as the GRU doesn't have near the same stackheight as most of the Hoka line, stability issues are not near as crucial.

Some folks have asked about the trademark midfoot "hump" that was very prominent in the original Skechers GoRun. The GRU does not have a noticeable "hump" in the midfoot. If you look at the detailed stackheights listed above, it's true that the midfoot stackheight is the thickest part of the shoe compared to the forefoot and heel stackheights. I ran in the original GoRun and did notice the midfoot "hump" that everybody talks about, I haven't noticed the "hump" at all in the GRU so no worries there.
As of this review I’ve easily put in well over 1000 miles in the various prototypes and final production versions of the GRU. Take it from me, the shoe has come an amazingly long way from the first prototype I received to the final version you’ll soon see in stores (see the "graduation" photo at the bottom of this post). Since my main goal was to have a shoe that I could trust to get me through the Wild and Tough Hardrock 100 in the San Juan Mountains of south-west Colorado, I put all the GRU prototypes through very harsh testing to simulate conditions and terrain I'd face in the race

The bulk of my testing was simply including the GRU in my pre-race training; mile after mile of steep, off cambered trail runs, often in very wet, muddy and slippery conditions. Around where I live a big trail hazard is wet limestone rock; I’m convinced this is some of the slickest stuff on the face of the planet! Very few shoes I’ve worn have been very effective on this type of terrain mainly because most trail shoes are very stiff (mainly because of full length, inflexible rock plates) and don’t use a sticky rubber outsole. Shoes that I've found to be very effective on wet and slick surfaces have either used very sticky rubber compounds on the outsole or had outsoles that featured significant sections of a soft, porous midsole exposed. The only line of shoes that I’ve used that have consistently been moderately effective have been the sticky rubber line of Inov-8 trail shoes. However, the problem I’ve had with the Inov-8 line is their limited underfoot protection and lack of ample cushioning that I believe is necessary for marathon or longer distance trail runs. Ironically I've had pretty good success on slick wet rocks while running in Nike Lunaracers or the Hoka Bondi B which both have almost no true outsole but have huge areas of exposed midsole EVA foam. While these shoes were great at sticking to the wet rocks they failed horribly in the mud and that exposed EVA really wore out quickly on rough surfaces. The GRU marries the above two features: sticky outsole compound and porous midsole. The GRU works so well on wet rocks (especially lime stone) I believe because of two factors: 

1) The midsole-outsole, while thick, is amazingly flexible and deformable which allows the runner to get a good, solid full footprint on any surface; something a more rigid trail shoe cannot do. 

2) The relatively porous Resagrip compound used in the GRU , like a deck shoe, the Resagrip compound seems to stick to wet surfaces. Ever notice how a sponge can grip pretty well to a wet counter top? That’s how the Resagrip outsole works. Seriously. Not only is the stuff porous but it’s fairly sticky as well which add another degree of traction through friction. I’d put the sticky Resagrip compound on par with the stuff Inov-8 uses in their sticky rubber outsole, with Resagrip being quite a bit softer.
In the mud, the GRU 's triangular shaped lug pattern has proven to be very effective. While the lugs are closely spaced which in a more traditional, inflexible, trail running shoe might cause excessive clogging of mud, the GRU benefits from having an extremely flexible midsole/outsole which works to “shed” any mud build up between the lugs.

On the road
While most of my testing of the GRU was offroad, I still did cover a substantial amount of mileage on pavement; especially before and after my Hardrock 100 training block. On the roads the GRU is very amply cushioned without feeling too squishy; a common problem of overly cushioned shoes. I used the GRU for several speed and tempo running workouts and felt the shoe had plenty of "pop" or spring. Unlike previous speed work I've done in Hokas, the GRUs didn't feel like I was fighting the shoe. That is, I've noticed that when I'm really trying to run fast and am up on the balls of my feet, the Hokas, because of their lack of flexibility feel a bit awkward underfoot and have even caused some slight underfoot discomfort. On the other hand, the GRU despite being thicker than a typical running shoe is A LOT more flexible and so feels much more natural underfoot. 

The closely spaced, flat profile, triangular shaped lugs on the road feel right at home; in fact you can’t feel the lugs underfoot which is a good thing and what makes this shoe an effective road-trail hybrid.


From my review so far one might think that I couldn't find fault with any aspect of the GRU. Unfortunately that's not the case but frankly it's not surprising that a first edition shoe might have some issues. The following is a list of shortcomings I and several other wear testers have noticed:

1) Midsole-Outsole roll stability.
While it hasn’t been a major issue, we’ve noticed that if you are a pronater then the current construction of this shoe won’t reduce that tendency. On the roads hardly anybody could sense any excessive pronation, but on the trails we all noticed that we tended to pronate a bit more. I think the cause here is the relatively narrow heel foot print. When you increase the overall stack height of a shoe you also need to increase the size of the footprint of the shoe to maintain overall stability. I don’t think we quite dialed in this stack height to footprint size ratio; but it’s close. I think the GRU will benefit greatly from having the overall heel outsole width (foot print) increased several millimeters. 

**UPDATED 27-NOV-2013**
I also recommend modifying the midsole-outsole mold design slightly to not only add several millimeters to the heel footprint width but also wrap the midsole-outsole around the heel of the foot a bit more giving the shoe more of a recessed, bathtube-like fit for the heel. I believe this modified design will add a lot more roll stability to the shoe. 

2) Upper durability. 
Several of the prototypes I tested had issues with the the upper fabric ripping right where the upper attaches to the midsole-outsole around the metatarsal flex area. This area of any running shoe has always been a weak link for me. Perhaps it’s how and where I run, but every running shoe I’ve ever owned that used an all mesh upper ended up tearing right where the bulk of the shoe flex occurs. The GRU was no exception and was frankly a bit disappointing. I figured that the relatively soft outsole would wear out much quicker than the upper but I was wrong. On several prototypes I tested (including the final version you’ll see in stores) it was always the upper that wore out first; totally blown out! However, this rapid upper wear has only been noticed by myself and one other wear-tester (that I know of) and not by the other wear-testers so perhaps it’s not a universal experience. I’ve friends who’ve worn the same all mesh trail shoes as I and never blown out the uppers like I have so who knows? I suspect the fact that I wear SuperFeet insoles in all my shoes could be the culprit as the relatively rigid insole does seem to protrude into the sides of the upper perhaps causing the excessive wear at that contact point? The “fix” would be to do a more traditional randing around where the upper fabric is bonded to the midsole/outsole. In shoes that do this, such as the Inov-8 X-Talon 212, I’ve yet to blow out the upper while the X-Talon’s cousin the Bare-Grip 200 (unranded) I blew out in less than 100 miles! 

3) Midsole-Outsole durability.
Since there are no high-friction patches or buttons used on the GRU I’ve noticed that the outsole does tend to wear relatively quickly, especially with use on the roads. While we do have very rocky, rooty and technical trails around my neck of the woods in the deep south, what we don't have are extremely abrasive trail surfaces such as rough granite. However, I did thoroughly shred the relatively soft midsole-outsoles like cheese through a grater after a couple of San Juan peak bagging scrambles over rough and sharp granite talus.  Still, overall, the wear rate is better than other Resalyte only outsoled shoes I’ve tested (GoRun line, GoRun Ride line, GoBionic line etc…) but the GRU would benefit greatly with the inclusion of some high-friction compound patches and inset buttons in the typical high wear areas of the heel, midfoot and toes.


Overall, despite its minor shortcomings, the GRU is a real bargain and I strongly feel it's a great product that will work well for a lot of different runners for lots of different reasons.  The GRU worked extremely well during the many months of training leading up to and including my goal race the Hardrock 100 this past July. For a first edition, high cushion hybrid road-trail shoe, something completely new and different for the Skechers Performance Division, I think they did a very good job. Some of the Skechers Performance Division folks commented near the end of this journey that this was one of the most thoroughly tested and re-tested first edition shoes they’ve ever worked on. I think a lot of first edition shoes end up being beta tested by consumers themselves and are then improved drastically in subsequent generations of the shoe. It’s my belief that most of that beta testing has been adequately handled by myself and my fellow wear-testers. We shredded the early prototypes so you, the consumer, won’t have to! 
So who is this shoe for? The show is for anybody that’s looking for an affordable, super cushioned though highly flexible shoe. It’s a great shoe for putting in the long miles when you need more cushioning for your legs and feet. It’s also a great recovery run shoe for after a hard workout. It's also very comfortable to just wear around town, to work and play.

Odds and ends
Skechers GoRun Ultra, lifestyle model with faux suede "Leatherex" upper.
In addition to the performance minded Skechers GoRun Ultra, a lifestyle or everyday use version is also available. The "Leathertex" upper material is sort of a feaux suede leather and looks really sharp. 

Graduation Photo: Skechers GoRun Ultra class of 2013. Just a subset of the many GoRun Ultra prototypes I tested (a few didn't live long enough to graduate). From left to right is roughly the prototype progression, right most is the final production model.

Any further questions about the Skechers GoRun Ultra? Please feel free to contact me using the form at the bottom of my blog. Thanks!