Is Shimano's GF800 GTX finally the flat pedal winter boot we've been waiting for?

Rich Owen has been testing Shimano's new flat pedal winter boot to see if it measures up

A pair of Shimano flat pedal winter boots
(Image: © Rich Owen)

Early Verdict

While they're comfortable, grippy and protective, the GF800 GTXs aren't quite fully waterproof, but they keep the your feet drier than any other flat pedal MTB footwear we've tested and have become my go-to riding shoes for foul weather.

Pros

  • +

    Foul weather resistant

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    Decent pedal grip

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    Comfortable

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    Sturdy toe and heel

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    Easy and quick Boa fastening

Cons

  • -

    Not fully waterproof

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    Snug fit makes putting on an effort

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    Slightly baggy ankle cuff

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    Not ideal for shorts devotees

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Shimano announced the launch of a new range of trail/gravity orientated MTB shoes a few months back and one model that caught the eye was the SH-GF800 GTX – a winter boot for flat pedals enhanced by Gore-Tex protection. As I (mostly) ride on flats, this model piqued my interest, as while there are plenty of winter MTB boots for clipless pedal riders, the list of foul weather footwear options designed for flat pedals is very short. Arguably the best previously existing option, the Five Ten Trailcross Gore-Tex, isn't really a winter boot at all, and we didn't really rate the Leatt 7.0 HydraDri boot.

A single Shimano flat pedal winter boot viewed side on

A Boa fastening system is an upgrade on laces – particularly in foul conditions (Image credit: Rich Owen)

Design and specification

The GF800 GTXs feature Shimano's newly reformulated Ultread rubber outsoles in a compound called GF which is specially formulated for flat pedal shoes. Shimano say the GF rubber used for the GF800s is different again, and has been specifically designed to deliver "optimal performance in cool and cold weather, enhancing pin engagement and shoe-to-pedal connection". The hexagonal tread is tightly spaced near the arch of the foot, but the spacing gets roomier nearer the toe and heel for improved walking grip.

The outsole of the Shimano flat pedal winter boot

While there's more testing to do, I've been impressed with the grip from the Ultread sole so far (Image credit: Rich Owen)

While the stitched and glued upper panels are designed to keep the worst of the weather out, there are ventilation holes in the toe section and outer face of each shoe. A waterproof flap partially covers the 'lace' section, but rather than laces the GF800 GTXs have been specced with a wired Boa closure system – which Shimano says was selected for easier operation with gloved hands.

A Gore-Tex 'sock' lines the interior of the shoes which is designed to help keep the elements at bay as well as giving maximum foot comfort. There's insulation between the sock liner and the outers which should help keep things warm when temperatures start to bite. The interior of the ankle section gets extra padding with an extra padded lip above heel to help stop feet from lifting. The ankle section finishes with an elasticated cuff (designed to keep the heat in and splashes out) with looped pullers at front and rear to make getting the shoes on and off easier.

Upper view of the winter boot

A stretchy waterproof flap covers the lower part of the 'lace' of the lace section, while trail pants cover the ankle cuff (Image credit: Rich Owen)

Performance

As things stand, the temperatures haven't dropped low enough to test the GF800 GTXs in a proper winter conditions yet and I want to put more time into testing them before giving them a full review. However, it has been ridiculously wet of late which has given me plenty of opportunity to see how they measure up on sodden rides with trails with the consistency of watery blancmange.

My size 43 EU (US 10, UK 9) test boots were an accurate fit for me. But despite my fairly narrow feet, getting them into the GF800 GTXs on was a bit of struggle right from the off. Handily, the pull loops at the front and rear of the ankle make the job do-able. Once on and Boa-ed up, the Shimano boots immediately felt snug and comfortable – just what you need for foul weather riding – though the cuff wasn't tight enough to fit securely around my ankle.

On the bike, pedal grip felt secure and vastly improved from previous Shimano flat pedals shoes I've ridden in (their GR9 shoes have a good reputation for grip, but I've not tested them). I've only ridden my local trails in the boots so far which rarely test the need for secure pedal grip. However, with trail conditions have being properly nasty during all my testing so far, the GF800 GTXs have performed very well despite pedals and boots being hit with all manner of trail slop.

While we're on the subject of slop, the boots did a sterling job of restricting mud resembling all seven types found on the Bristol Stool Scale to the outsides only and despite my efforts to smash through every puddle I could find, only minimal amounts of moisture found its way through to my feet. I wore trail pants rather than shorts for each ride, but none of pants I wore were designed to be completely waterproof.

A very muddy boot on a very muddy trail

Despite being outwardly covered in gunge, my feet have remained comfortable inside the GF800s through all my testing so far (Image credit: Rich Owen)

First ride verdict

My testing so far has been exclusively on rides in conditions when I was peering out of the window really questioning whether heading outdoors really was a good idea or not. However, after the first ride in the GF800 GTX boots I knew at least my feet would still be comfortable throughout even if the rest of me was sodden and covered in crap.

A small amount of dampness did find its way through to my feet, but as yet I'm not sure if it was via the somewhat baggy ankle cuff, directly through the seams, the ventilation holes, or perhaps all three. My feet remained warm though and not too hot even though temperatures were around 53.6 F (12 C) degrees.

I will be updating this article once I've tested the shoes in full blown winter conditions and on tougher trails, but so far I've been impressed with the GF800 GTX boots.

Tech specs: Shimano GF800 GTX winter boots

  • Price: $220 / £219 / €219
  • Weight: 890g per pair (size 43 tested)
  • Sizing: EU 38 (US 6, UK 5) to 48 (US 13.5, UK 12.5)
  • Colors available: Black, Khaki
Richard Owen
Editor, Bike Perfect

Rich has been riding mountain bikes for over 30 years and mostly likes hitting flowy yet technical trails that point downhill. A jack of many trades, he has competed in cross-country, enduro and long distance MTB races, not to mention also now adding gravel to his riding repertoire. A resident of North Devon, he can mostly be found pedaling furiously around his local trails, or slightly further afield in the Quantocks, the Mendips or Exmoor. 


Current rides: Merida One-Forty 6000, Banshee Paradox

Height: 178cm

Weight: 68kg