Aku Mio GTX Shoe Review

10th Oct 2016

mio gtx

Like many outdoor folk, approach shoes are my day to day footwear choice and yet, until a decade or so ago, I’d never even heard the term.  We used to walk up to climbs and do pretty much everything else in trainers and, although it never did us any harm, approach shoes have certainly improved general purpose outdoor footwear massively - having durable, grippy, snug fitting, water resistant/proof and supportive shoes improves efficiency, safety and comfort.  

Of course there is now a massive selection available with every footwear manufacturer aiming to cater for the growing market, but fortunately, among some fluff, there are brands offering a shoe that has clearly been designed and manufactured to offer the performance you'd value most in the mountains.  

I was recently offered the chance to try some of Aku's Mio GTX shoes and, having loved the Aku Superalp NBK GTX boots I tested earlier in the year (my review is here), I had high hopes for one of Aku's high end approach shoe range.


The term 'approach shoe' seems to have been adopted to cover many variants, but Aku deliberately describe the Mio as a 'multifunctional and multipurpose shoe' which is perfect, they say, for ‘mid-mountain trails and active outdoor activities’.  

With this broad user range in mind, the Mio's feature an air mesh upper reinforced with micro suede and PU, a Vibram sole unit for use on varied terrain, a Goretex insert for waterproofness, stiffened last with softer spacer layer to allow support while still offering comfort and a cushioning felt footbed.  I had been impressed by Aku's attention to detail with the Superalp and the design detail put into the Mio is just as impressive.  The next question was how they'd perform?

In Use

I have been using the Mio for several months in a variety of situations.  The majority of use has been while working on Peak District and Snowdonia climbing courses over the summer but they have also been on a trekking trip to Morocco, used in conjunction with a pair of flat pedals on several mountain biking outings and used extensively as everyday footwear.  This means they have been put through their paces in a wide range of conditions - from the dry and dusty trails of Morocco to wet gritstone and slippy heather and from blocky sandstone to edging on grit Vdiff grade climbs.

mio gtx 2

How did they perform? 

As mentioned above, there are a lot of clever designs features in the Mio - design features that, I'm glad to say, really contribute to ensuring these shoes perform. 

The first thing I noticed, on initial fitting, was how comfortable and yet supportive they are.  Aku have combined a fairly firm last with a softer PU layer and a felt footbed and this is a great combination as the Mio's feel comfortable and yet relatively stiff.  This is then combined with a well shaped reinforced mesh upper to encase your foot superbly.  As with any shoes, I would say that you need to ensure these fit your foot shape, but I have a fairly regular foot and they fit mine perfectly.

In use this snug fit has been a real boon.  The Mio's didn't immediately strike me as a replacement for the 5.10 Guide Tennies that I regularly use for scrambling around on climbing courses, but as I've got more and more confident in their ability, I have comfortably climbed Vdiff to severe grade routes in them as well as finding them perfect for hopping around on crag tops.

Of course, this snug fit wouldn't offer that performance without a suitably grippy sole, but here Aku have again worked wonders.  The Mio features Vibram's S864 Megagrip sole unit which is designed to offer excellent traction on both wet and dry surfaces while providing durability.  The soles really deliver.  We have had a good weather summer but there's no denying that even in a dry UK year you'll always still have plenty of wet surfaces to contend with.  

Again, I wasn't immediately sure how the Mio would cope because on first inspection the sole unit seems to be a pretty hard compound.  A tougher compound obviously helps with durability but I've still found the Mio to perform really well on both wet and dry rock.  The sole also has plenty of tread to help cope with everything from mud to wet grass and loose pebbly ground.  I took the shoes out mountain biking in what turned out to be one of the wettest and muddiest days of the summer and they really delivered because the sole offered the grip and stiffness to cope on flat pedals while still offering the grip needed for the muddy ground.  It's a great multi surface sole. 

Aku have used a felt footbed and softer PU layer combined with a stiffened last.  This combination works really well for walking and climbing plus the stiffer sole is also great for biking.  I imagine it would work well for other activities too.  The shoes initially felt rather hard but I soon got used to the felt footbed and PU layer combo working together.  I don't think the Mio's are ever going to climb as well as a pair of Five Tennies, but as this shoe is designed for multi use rather than a specific task then they do climb very well.

The use of a Goretex insert also offers a highly breathable and yet waterproof shoe.  The breathability helped in the hot and dry conditions of the Atlas Mountains recently and still the waterproofness kept my feet dry on the wet trails or on wet weather climbing instruction duty over the summer.  There are obviously always limitations about how deep the water is that you can go in with a shoe but they do seem genuinely waterproof.  The tongue is stitched high and the membrane also comes high on the tongue which ensures water can't leak in.   It is also interesting that with these inserts the Goretex becomes the liner membrane and so, although I haven't used them long enough as yet to comment on long term durability, they have certainly stood up to everything I've thrown at them so far without visible signs of wear.  

The Mio uppers combine a mesh layer with suede and PU reinforcements.  I have been very impressed with the breathability of this mesh and my feet were comfortable enough in 35 degree temperatures (well, certainly as comfortable as any feet can be in those temperatures that is!).  The mesh would be pretty vulnerable to damage so Aku have added suede reinforcements at all lace points and this extends to make a rand of suede around the whole shoe.  Added to this, the toe and heel are further reinforced by PU sections.  The upshot of all this is that the shoes have had no problems coping with wear on plenty of loose rocky terrain and on many gritstone days out.  Again, Aku seem to have thought carefully about all potential wear points and their planning has paid off so far.

The lacing arrangement is a mixture of tape loops and small metal buckles which the laces get threaded through.  It is a fairly standard arrangement which works well and the loops are low profile enough to avoid them getting caught on anything.  They also seem very durable. 

Aku, like any manufacturer, knows that technical features are only one consideration for potential customers - their footwear has to look good.  The Mio's are perhaps less 'flashy' than some models on the market but are certainly a smart looking shoe.  The ones I have been using are a mix of black and grey with dashes of lime green.  There are other colours available but I really like the look of these.

mio sole


There really isn't anything at all that I feel could be improved with the Mio's.  They are, like the other Aku footwear I have tried, superbly made.  They also, again like other Aku footwear, do a great job of what they are designed to do.  They aren't cheap at around £115, but for that money you are getting a high quality shoe that has definitely proved to be multi-use.  You are also getting footwear that I think will last a long time.  Another great product from Aku.

Posted by Paul

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