The Shimano RX8 shoes broke new ground with their release in 2019 as the world’s first gravel-specific design, but the real estate they occupied looked bijou at best.
Even within Shimano’s own range, the RX8s had to try and muscle in between the sleek and efficient road line, topped by the S-Phyre RC902s, and the rugged MTB range, topped by the S-Phyre XC9s.
After more than 18 months of regular use though, I’ve come to view the RX8 shoes as the most indispensable pair I have available.
Shimano says the RX8s were created in an attempt to blend the practicality of its mountain bike-focussed SPD system with the light weight of its road-going SPD-SL system.
As such Shimano has approached the design by stripping back from the MTB side rather than bulking up a road shoe.
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It has kept many aspects that would logically be pertinent to retain for the rough and tumble of gravel riding but has removed some of XC line’s meatier features to bring the weight down more towards the realm of road shoes.
That means the RX8 shoes still feature the abrasion resistant TPU lugs, the heel stabiliser and stiff carbon composite sole of the XC9 shoes, but replace one Boa IP1 dial with a lighter velcro strap, size down the heel cup, and lose the spike mounts entirely.
According to Shimano, the changes save around 60g over the XC9s. I weighed my size 43 sample RX8s at 291g per shoe.
By way of comparison a pair of S-Phyre RC901s (the forebear of the recently released RC902s) in the same size weighs 257g per shoe. That means the RX8s do indeed get close to a top-end road shoe weight despite including several features from Shimano’s top-end MTB shoes that make them better able to cope with tougher conditions.
Considering this has all been achieved at a retail price some £100 cheaper than both the RC902s and XC9s, it is an impressive feat. It marks the Shimano RX8 shoes out as remarkably good value even before their a-bit-of-everything performance in the real world is considered.
The finish of the RX8s upper is a classy pattern of angled etching that catches the light in different ways to create a tone-on-tone camo appearance, but despite its looks it is also hard wearing.
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The TPU bumpers that extend from the sole onto the upper at the toe and heel do a good job of fending off damage in the most impact-prone areas. Even so, the uppers have been hit by rocks, mushed into gravel and whipped by brambles in the time I’ve used them. Despite some small marks they have capably shrugged off the worst of the abuse.
Being made by Shimano, the RX8’s general build quality is beyond reproach and over the extended test period there’ve been no incidences of seams unstitching or glue failing.
The tread and dimpled layer that largely covers the stiff carbon sole plate is made from a hard plastic material, Shimano’s thinking being it should deform less under compressional pedalling loads. Due to its inflexibility it is wearing reasonably well but although it digs into soft ground well, I wouldn’t say it is the grippiest solution on hard surfaces.
The tread is also a little narrow, extending to just 69mm wide at its widest point by the cleat recess. In comparison the tread on Specialized’s S-Works Recon shoes extends to 80mm at its widest point, also in a similar area.
Consequently I felt as if I was a little more aware of the possibility of turning an ankle on uneven ground in the RX8s, but will admit that any actual incidences were no more frequent than in other shoes.
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Shimano can provide a solid rationale behind this perceived chink in the RX8’s armour. The tread pattern is the width it is to provide better pedalling stability, marrying up as it does with the body of Shimano’s SPD pedal design.
Given the time spent on a bike while gravel riding (quite a lot) versus the time you spend off it (not much) I’d say overall this is a worthwhile compromise to make, although it would be nice to see the tread blocks widened slightly if the shoe is revised.
For all the RX8’s ruggedness their fit is another aspect that comes close to matching Shimano’s road shoes.
The upper adopts Shimano’s proven ‘360° Surround’ design where the inside half of the upper wraps over and around the outside half – think of the closure happening in a similar fashion to how you would shimmy a rolled-up poster into a tighter cylinder.
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This lets the upper close around your foot rather than down on top of it. Despite a secure hold, it doesn’t create any uneven pressure so I found the shoes could stay cinched up indefinitely. I never found the need to release the tension at a cafe stop, for example (when such things were allowed).
The Velcro closure across the toe box is likely to be set-and-forget but the lacing pattern of the Boa IP1 dial works with the cut of the upper nicely. I found it wrapped the shoe around my mid-foot consistently and securely.
The RX8’s overall shape is typically Shimano. They are snug at the heel – even snugger than the S-Phyre RC901s incidentally, thanks to more generous padding – but open out to provide some generous width at the toe box. It is a combination that should accommodate a wide range of foot shapes.
Personally I have a narrow heel, high instep and a wide, low-volume forefoot, which are attributes that generally suit Shimano shoes very well. The RX8 shoes include arch-adjustable insoles (a huge value-add that is often missing even in shoes that are considerably more expensive than the RX8’s, I’m looking at you Sidi), so with the high wedge insert installed the shoes were supremely comfortable.
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The best of both
Shimano has done an excellent job of taking features from its road and MTB groupsets and homogenising them under the GRX name to create something comparable to both, but unique in its own right.
The brand has achieved similar success in the RX8 shoes using a similar tactic.
While I’d still prefer the security and efficiency of a road shoe for outright road riding and the burlier, more relaxed design of MTB shoes for full-on mountain biking, for the gravelly space in between (plus the occasional informal forays into both other disciplines), the Shimano RX8 shoes are a fantastic option.
Source: Cycling – Cyclist