Shimano GF6 Review

I’ve gone through a lot of non-SPD mountain bike shoes over the last six years, ever since I switched to riding flats on my mountain bike. That’s not something I’m particularly proud of, but fortunately, I haven’t tossed many into the landfill. Instead, I have a shelf in my workshop that’s dedicated to well-worn MTB shoes. It drives my partner Virginia nuts, but I still use many of them, and most still have plenty of life left in them. Plus, whenever my tenure as a professional bike shoe reviewer ends, I’ll have a collection of dirt-dancing footwear that should last me until I’m too old and feeble to pedal a bike. The used shoes I’m particularly fond of are those that show very little sign of wear after a lot of use; and Shimano seems to be pretty good at accomplishing this. So, when they released their new Shimano GF6 (SH-GF600), a top-of-the-line, lace-up gravity shoe, I thought I’d try them out and add another pair to my collection. I was able to pick up the GF6 and put them through all forms of wear and tear in Oaxaca, Mexico, this winter. Read on for my long-term review.

Last year, Shimano unveiled an extensive lineup of new mountain bike shoes featuring both clipless and flat pedal options. As I mentioned in my revamped Flat Pedal Shoes for Cold Weather Roundup earlier this year, the standout was the GF800 GTX. However, I was also intrigued by the GF6 (aka GF600), which has a similar form factor to the GF800 but sits at the top end of their “Gravity Flat” lineup, a subset of the range made for high-speed and relatively aggressive singletrack pursuits.

Like a lot of other gravity-oriented flat-pedal shoes, the Shimano GF6 is made with an EVA midsole, reinforced panels, an asymmetrically raised padded ankle collar, and a synthetic leather upper that comes in boilerplate black or brown color options. However, I realized these shoes are pretty special while putting them through their paces on some of Oaxaca’s finest and most challenging singletrack. One thing that really stood out about the GF6 is how composed and in control they felt while going fast and negotiating technical bits of trail. There are a few things that contribute to this, which I’ll dig into throughout this review, but I think part of it is what’s under the hood. The GF6 is built around an engineered shank Shimano calls the “TORBAL 2.0” torsional plate, which, according to their marketing spiel, “offers just enough outer edge and sole flexibility to provide excellent control on aggressive descents and corners.”

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Those types of statements are always dubious, but I found the GF6 to have nearly the perfect amount of flex and stiffness for pedal feel and control on singletrack. They aren’t nearly as rigid as the GR7 I tried back in 2020-21, but they’re stiffer than other flats I’ve tested, including the GF8 GTX, which is a little too flexy in my opinion. I’d give them a solid medium stiffness rating compared to all the other flat shoes on my shelf. Shimano assigns the GF6 a three in their stiffness scale, for what it’s worth.

Fit and Comfort

Another factor that contributes to that sentiment has to do with how these shoes fit. Shimano engineered the GF6 to have a tighter fit around the ball of the foot and a roomier toe box. I have generally narrow feet and long toes, so both of those characteristics are critical to me and are largely what makes the GF6 one of the better flat shoes I’ve tried. The shoe effectively hugs the mid-foot area and still not cramping my toes. That translates to a very secure feeling on the pedal platform, a characteristic I’ve come to really appreciate the more I ride flats on technical trails.

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Still, I can’t say the GF6 is unbelievably comfy. They’re not uncomfortable, but they’re also not the kind of shoes you put on and immediately feel like you’re walking on clouds. With the lace-up design, it’s easy to even out the pressure throughout the shoe and they feel very balanced. However, they don’t have a ton of arch support. Inserts could fix that if it’s a concern. That being said, they also didn’t bother me on long days. I took this pair on a few bikepacking trips that involved multiple 10-12 hour days and didn’t have any issues with discomfort or foot pain during those rides.

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Off the Bike

The GF6 does surprisingly well on hike-a-bikes and rock scrambles. The deeper lugs and linear-shaped tread at the toe help maintain traction, even up steep and loose rock, which is a common theme in Oaxaca. Similar to the GF8 GTX, it’s not great on wet leaves and mud, but it’s also not that bad. Overall, I think Shimano struck a fairly good balance of pedal grip with front and back traction.

Pedal Grip

It seems like Shimano continues to improve their tread compound. I’ve tried several of their flat shoes over the last five or six years, including the GR7 mentioned above, and they simply keep getting grippier. The Ultread GF (Gravity Flat) compound isn’t the stickiest shoe rubber out there, but it’s pretty damn good. I also really like the smaller lug pattern as it’s generally easy to adjust your foot placement on the pedals, and once you’re moving, the tread provides an adequately locked-in feeling, especially when descending. As I’ve mentioned before on other shoe reviews, one important aspect to pedal grip on bumpier downhills is the midsole. The GF6 has a layered EVA midsole like other gravity-oriented flat-pedal shoes, but it feels pretty well-refined compared to some others and does an excellent job of absorbing hits and impacts, which contributes to the shoe’s solid pedal grip and control.

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Durability

Perhaps the most impressive thing about the Shimano GF6 is how well they’ve held up. As mentioned, I’ve put over 1,500 miles on this pair, much of which was in Oaxaca while bikepacking and trail riding on some pretty gnarly terrain. That included plenty of hike-a-bike escapades and a lot of tough singletrack. First off, I’m amazed at how little pedal scarring there is. This may be one of most hardwearing outsoles I’ve tested. As you can see in these photos, there’s really little wear and tear.

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Second, the upper actually looks better than it did when it was new, although I always think gear looks better with a dirt patina. Dirtbag aesthetics aside, the GF6’s skate-style pleather upper has gone unscathed, and there aren’t really any signs of wear throughout. Perhaps the reinforced rigid toe cap helped in that regard, but it seems like the GF6 is well-built but not overbuilt, which is evidenced in the shoe’s 425-gram form factor.

Unfortunately, I can’t claim that I tested how the GF6 faired with water and rain as I’ve mostly ridden it in the desert, but it seems to be well-vented. The perforations on the sides and forefoot certainly help, and I haven’t really noticed my feet overheating, even during rides in 80-85°F temps.

Sizing

The Shimano GF6 comes in sizes 38-48 that are specified through adaptive sizing, which is a little tricky. I typically wear a men’s US size 9.5 or 10, which usually translates to a EU 42.5. However, the GF6 size US 9 correlates with an EU 43 in Shimano’s sizing chart. That was the logical choice, and fortunately, it fit perfectly.

• Model/Size Tested: SH-GF600, size 43
• Actual Weight (pair): 850 grams (30 ounces)
• Place of Manufacture: China
• Price: $160 at Jenson Backcountry
• Manufacturer’s Details: Shimano

Further Reading

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