SHIMANO GR903 FLAT PEDAL SHOE REVIEW

Words by Robert Johnston
Photos by Bike Connection Agency – Mirror Media

Shimano’s GR9 shoe has been the flagship model in their range since 2018, receiving a couple of updates along the way to keep it relevant. With the release of their new in-house performance rubber sole, ULTREAD, Shimano refreshed their mountain bike shoe line up and delivered the third generation of GR9 shoe: the GR903. We’ve been hammering a set for the last couple of months, and it’s time to share our thoughts.

THE LAB

The highlight feature of the GR903 shoes is Shimano’s new ULTREAD gravity mtb shoe technology. ULTREAD is a brand-new sole with a proprietary ULTREAD GR rubber blend and precision engineered tread design, claimed to offer “superior durability and extraordinary grip”. Underneath the toes and heel are zones designed to offer the best purchase on the terrain when walking. The rest of the sole features a hexagonal design with relatively deep recesses to allow pins to sink in deep, while retaining the freedom of movement to reposition the foot when required. The width of the tread is increased considerably under the arch compared with many shoes, offering up increased real estate for the pedal in the most favorable zone.

The main body of the shoe is constructed from synthetic leather, with mesh portions added to key areas and perforations made in front of the tongue to improve ventilation. An asymmetric design with strategic padding offers increased coverage on the inside of the ankle, keeping overall weight low without sacrificing protection. The toe box gains some extra volume to ensure things remain comfortable, and the wider fit of the toe through to the midsole ensures gravity riders are catered for. Under the foot there is EVA foam and a shank plate to add stiffness and damping where required. Moving further up you’ll find the Volume Tour last which defines the overall shoe profile, and their Volume Tour insole to give the final under-foot fit.

A gaiter is added to wrap around the ankle and keep the loam out while improving the stability of the shoe in use, and there’s a toe box included to offer protection from rocks and stumps on the trail. The GR903’s use laces to secure the fit, with metal eyelets added to all holes for durability and an elastic lace tidy built into the tongue. Offered in a choice of white or black colorways, the GR903 shoes are offered in Shimano standard sizes from EU38-EU48 (US 5-15), weigh in at 854g for a pair of EU45’s, and retail for $170/£139.99/€149.99.

THE DIRT

I (Robert, European Tech Editor) had the good fortune to make the journey to Massa Marittima in Tuscany, Italy, for the Bike Connection Agency Mountain Bike Connection 2022 event in February. During this time, I met with a bunch of cool and interesting European companies to learn more about their product ranges, and managed to get a small sample of trail time on board most of them to report back with my initial impressions.

Shimano was showcasing their updated shoe lineup, with a particular focus on their new ULTREAD sole tech. Following a short presentation on the tech, they supplied me with a set of their GR903 shoes to test along with a pair of XT M8040 flat pedals, and sent me on my way to hit the nearby Massa Vecchia trails. I was riding a Canyon Spectral 125 at this point, and it was to be my first run down the unfamiliar trails on an unfamiliar bike, so the last thing I wanted to think about was my feet.

Unfortunately, the XT pedals were supplied with the short pin option, which only protrude 3mm or so from the platform. This could be enough to catch reasonable purchase on a select few shoes, but when combined with the GR903’s hexagonal ULTREAD sole the amount of grip on offer was minimal. After a tumble thanks to my feet blowing off in a rut on the first run, it was time to go back to the drawing board. I managed to secure a set of Saint PD-MX80 pedals that were equipped with longer pins and theoretically should have provided a match made in heaven. Things did improve, but their smaller platform was dwarfed by the huge usable tread area on the GR903’s and so the true potential was yet to be unlocked – that would have to wait until I returned to the UK and got on board some of the better flat pedals in my repertoire: DMR’s Vaults and the OneUp components Alloy pedals. What my time in the heat (for my Scottish blood) of Massa Marittima did tell me was that the GR903’s are a nicely ventilated shoe that let a notable amount of air flow through when on the move. Additionally, even with a smaller pedal that could risk some foot pain on the extended descents, the shank and EVA foam underfoot combined to offer enough cushion to keep things comfortable.

Back home and on a set of worthy pedals, the GR903’s improved further, but didn’t reach the grippy heights of the best of them. There was a definite bedding in period, during which the sole softened ever so slightly to improve the feel underfoot and the rubber became slightly tackier. But unfortunately, the maximum grip on tap never stacked up to the likes of FiveTen’s Stealth rubber, sitting at a solid 8 on my scale to the FiveTen’s 10. That said, on a pedal with pins that sit nicely in the recesses in the ULTREAD sole the grip was tolerable in all but the muddiest conditions. The rubber is a little on the hard side, but there’s reasonable mechanical grip generated by the physical locking of the pins in the sole. The positives of this are an impressively wear-resistant sole that’s easy to reposition on the pedal, showing only minor wear after a lot of trail time. Thanks to the incredibly generous real estate for the pedal to sit, you can make use of different parts of the foot to weight the pedal differently, too.

Walking in the GR903’s is reasonably comfortable, thanks to ample flex in the front to conform to the ground below, ample padding and effective traction generated by the walk-specific zones on the ULTREAD sole. The reinforced toe box manages to fend off light impacts with obstacles and the ground, without being a nuisance when walking like some can be, and the padding on the sides of the shoe seem effective without being at all bulky. The laces are sturdy and let you really cinch the shoe down to prevent any rub around the foot, and the thin tongue does a good job at spreading the pressure over the foot to avoid any hotspots. Unfortunately, the gaiter doesn’t quite manage to keep all the roost out, and the tongue isn’t gusseted to keep any dirt from entering further down the foot, so mud and small stones can work themselves in. Overall, the shoe feels great, and if it weren’t for the incredible grip offered by some alternatives rather than the good grip of the Shimanos, they’d be a firm favorite.

Who are they going to suit, then? I’d highly recommend the GR903s to a rider who perhaps doesn’t often ride trails that contain ultra-rough, high frequency bumps, but wants the protection and comfort. Their pleasant walking and ventilation would make them a good “adventure” shoe too, for drier rides that involve hike-a-biking mixed with some challenging trails where you’re not giving it full gas.

The Wolf’s Last Word

The Shimano GR903 shoes are damn good overall but lack the ultimate grip of some of the competition. For riders who don’t need the absolute most traction on the pedal they’re a fantastic shoe, but for riders looking for clipless-like pedal retention for the gnarliest terrain, you’ll be served better by some of the competition. 

Price: $170 / £139.99 / €149.99
Weight: 854 grams (EU45/US11.5)
Website: Bike.shimano.com

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