|For most people Merrell is often seen as a fashion brand, found in any number of high street shoe shops, but less seen in dedicated running or outdoor shops. It’s probably a fair comment to say that their previous ‘running’ shoes were distinctly more about form than function, though I have had good experiences with some of the trail walking shoes in years gone by.
This then is probably Merrell’s first real go at producing a performance running shoe and in an effort to get it right first time this was designed in conjunction with top American adventure racer Robyn Benincasa of Team Merrell Wigwam.
Starting from the ground up, the Overdrive features a Vibram Full Speed II sole, renowned for their durability and traction on all manners of terrain. The tread itself is moderately aggressive but definitely more trail shoe than fell shoe, particularly in the heel area. A one piece TPU polymer midfoot and heel shank provides good torsional and bending stiffness. The heel section in particular is interesting, consisting of a series of five horizontal ‘tubes’ which allow a small amount of compression when subject to a heel strike (aided by the cutaway section of the sole in the middle of the heel), but resist twisting of the heel for example when running off camber.
The midsole of EVA foam is of dual-density but symmetrical throughout leaving the one-piece TPU shank to effectively control over-pronation.
The midsole is a reasonable thickness in the heel for cushioning, without being too soft or too high off the ground which can cause instability off road. The forefoot section is thinner allowing for a closer ‘feel’ of the ground but still offering enough cushioning to keep things comfortable. There are some flexion areas designed into the sole in the forefoot which make it very agile and quick to conform to the ground.
The supplied insoles feature a raised grid pattern on the underside of the mid and forefoot areas, providing ventilation to the sole as well an extra bit of cushioning.
The upper is a fairly open mesh with a number of supporting ribs from the lace eyelets to the sole. There are four eyelets on each side and the lace is of the Kevlar quick-lace style that many are familiar with, though notably they come with an extra set of regular laces in the box too.
Once tightened up, the excess lace can be tucked into a garage in the top of the tongue. All in all and effective and secure lacing system, even if my test pair squeaked like a mouse for about two weeks of bedding in.
The heel has a pull loop and various bits of reflective detailing for 360o visibility.
On the whole, the sole was good, and contact points are still wearing well, however, traction could be intermittent on some surfaces. It took three weeks of sprinting down the back lane trying to get the bin out for the refuse lorry and falling on my face each time, to realise that the Overdrive is not the best performer on wet, mossy slabs. Some may say that nothing grips on those conditions, but I’ve certainly used better.
The stiff-in-the-back/flexy-in-the-front-nature of the midsole worked well and allowed the shoe to feel fairly stable on most trails when striking heel first but pretty fast and nimble when running up on the toes. A really good combination.
Throughout the hot summer, the open mesh upper was excellent, allowing excellent ventilation that negated the need to reach for the sandals or flip flops. When used for crossing rivers or kayaking of any sort, water drained extremely quickly and with the overall mass so low, these were great for races when shoes had to be carried and were my first choice of footwear in the Rat Races this year.
However, when the terrain was any rougher than a maintained trail I found the Overdrive less than ideal. Particularly when the terrain was tussocky, rocky or just generally rough, then the combination of a midsole stiff in torsion and a very lightweight, flexible upper failed to hold the foot in position. This caused my foot to roll around a lot within the shoe as well as just flexing the upper and letting my (notably wide) feet roll over the edge of the sole. On a number of occasions this led to me deliberately falling in an effort to avoid twisting my ankle. The upper foot would perhaps be more securely held with another lace eyelet and some stiffer, or more, supporting ribs from the lace eyelets to the sole.
If you are looking for the ideal adventure racing shoe, for use on rough terrain over extended periods then I think you can do better at the moment. However, if you’re looking for a fast, lightweight, shoe for use on trails, particularly in the summer, then I wouldn’t hesitate to recommend the Overdrive.
Available in Mens and Womens specific versions with a range of colour options.
For more details please visit: http://www.merrell.com