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ShimanoRX8 Mountain Bike Shoe - Men's


Item # SHI00ON

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  • Black, 40.0 ($250.00)
  • Black, 43.0 ($250.00)
  • Black, 44.0 ($250.00)
  • Black, 46.0 ($250.00)
  • Black, 47.0 ($250.00)
  • Black, 48.0 ($250.00)
  • Black, 49.0 ($250.00)
  • Black, 50.0 ($250.00)
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  • Silver, 40.0 ($250.00)
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Item # SHI00ON

RX8 Mountain Bike Shoe

Because gravel is still an emerging segment, some riders find themselves struggling with footwear choices—especially for racing. Mountain bike shoes offer great walkability, but are often too heavy and overbuilt. This leads many riders opting for lightweight road shoes with ultra-stiff soles that boost pedaling efficiency, but the lack of tread is not ideal for the inevitable hike-a-bike sections found in gravel race events and adventurous rides. Shimano addresses these problems by combining the best characteristics of their high-end road and mountain footwear into one shoe that's specifically designed for gravel racing. Lightweight and stiff, but with grippy outsoles and just enough toe flex to be comfortable to walk in, the RX8 might just be the best option out there for dedicated gravel enthusiasts.

The RX8 is constructed using a full-length carbon sole that rates at a 10/11 on Shimano's stiffness scale, ensuring hard pedaling efforts are rewarded with maximum forward momentum. The sole is then paired with abrasion-resistant TPU lugs that give you the capability to navigate terrain off the bike without slipping. The uppers are a tough one-piece synthetic with perforated venting that Shimano dubs Surround Structure, offering a good balance of holding power and all-day comfort. The design weighs considerably less than Shimano's flagship mountain bike shoe the XC-9, an impressive feat for a shoe that costs quite a bit less.

  • Featherweight shoes designed for gravel bike racing
  • Carbon composite sole ensures maximum pedaling efficiency
  • Surround Structure uppers provide a comfortable, glove-like fit
  • Lugged rubber outsole adds grip for hike-a-bike
  • Reinforced heel cup for stability under hard pedaling
  • Boa dial and toe strap make it easy to get the right fit
  • Perforations in the upper let your feet breathe
  • Wider cleat-to-pedal interface is optimized for XTR M9100 pedals

Tech Specs
Upper Material
synthetic leather, mesh
Boa® IP1 dial, hook-and-loop strap
high-density cup insole with adaptable arch pads
[sole] carbon fiber composite, [outsole] abrasion-resistant TPU lugs
Cleat Compatibility
Recommended Use
Manufacturer Warranty
1 year


Cycling Footwear
35   4
36 4 5
37 4 5.5
37.5 4.5 6
38 5 6.5
38.5 5.5 7
39 5.5 7
39.5 6 7.5
40 6.5 7.5
40.5 7 8
41 7.5 8.5
41.5 8 9
42 8.5 9.5
42.5 8.5 10
43 9 10.5
43.5 9 11
44 9.5 11
44.5 10  
45 10.5  
45.5 11  
46 11  
46.5 11.5  
47 12  
48 12.5  
49 13  
50 14  

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    What do you think about this product?



    How do these Shimano's compare in sizing to SIDI (road) shoes? I wear a 43 in the SIDI's. Based on the reviews here, seems like sizing is a bit erratic?

    >Rating: 5

    Stiff, lightweight gravel shoe

    I've used it once or twice and have initial impressions
    True to size
    Size Bought
    6` 1"
    175 lbs

    Typically wear a size 10.5 sneaker. Came from a much heavier and softer-soled pair of Bontrager mountain bike shoes in size 45. Ordered 45 here and fits like a charm. The tongue-less "burrito" design of the RX8 gives a more snug, road-shoe-like fit, and the boa dial has been great for making small adjustments. Carbon soles are nice and firm and I've been very happy with them so far. Would buy again!

    >Rating: 5

    Yep, seems like a winner.

    I've used it once or twice and have initial impressions
    True to size
    Size Bought

    Bought these as an all-road shoe, definitely feel a lot more ‘roadie’ than my XC pair, but in a good way. Only a few miles on them, but I am very pleased so far. Great price to value ratio compared to similar shoes with the stiff carbon sole, boa closures, adjustable arch insole, light weight, etc. True to size relative to my previous Shimano SPD shoes. I have slightly wider feet, the fit is snug but not too tight. Feels like a similar fit as my Giro’s in size 45, which tend to run small. I needed to put a set of the little oval Shimano shims under the cleats to alleviate some of the rubber outsole/pedal interface for easier entry and exit, but that’s more of a personal preference. Looking forward to putting some real miles on them this season.

    >Rating: 5

    Runs a bit small

    Runs small

    Great looking shoe with a carbon sole for a reasonable price, runs about 1 inch shorter or full size shorter then my S works road shoes, but is definitely a wider or more roomy fit just not as long. Would recommend to someone looking for a roomier fit, just go by the Shimano chart, Specialized shoes are a bit longer and narrower then these. Usually wear a Specialized 46 and going with a 47 in these, the Shimano 46 was way too small.

    Can confirm this. Wearing Specialized in 45.5 and the Shimano's in 46 are a tight, but good fit.

    >Rating: 5

    Runs a size large

    I've used it once or twice and have initial impressions
    Runs large

    # Sizing After trying a few pairs, I ended up with EU47. (I wear a US13 Nike). Shimano's size chart says US13 = EU49, which is definitely too large. # Weight EU47 = 325 g, each including 25g OEM insole. # Pedals Fits Crank Brothers Eggbeaters without traction pads.

    Hi Jeff, Can you clarify your comment? Do you typically wear a US13 or a US12? Shimano actually specifies an EU47 for US 12 and an EU 49 for US 13. The only shoe manufacturer that matches EU46 to US12 (that I'm aware of) is Specialized and those tend to run 12.5US oddly enough. Typically EU46 = 11.5US. Thanks!

    I just wanted to add - I tried sizing down to a 44 and could barely get the shoe on. In specialized I am a 44.5. Waiting for 45s to come in and will give them a shot. My normal shoe size is generally 10.5-11. My experience is that they don't run large.

    I have worn out my current gravel shoes after about 8 years of use. I wear a US 12 in Nike and my current Shimano shoes for my road bike are 46 and I love them. When I looked at size chart I was thrown off but you answered my question. Going with a 46!

    >Rating: 5

    Great shoes!

    True to size
    Size Bought

    Bought these for gravel rides but now I use them for all my MTB and gravel rides! Shimano got it right with this one.

    >Rating: 5

    A Road Shoe w/MB Cleats

    I've used it several times
    True to size
    Size Bought
    5` 11"

    I really wonder if someone at SHIMANO screwed up with this shoe. It is a great deal and a great value. It is fantastic if you are looking for a seriously light, stiff shoe to put a lot of road miles on your MB pedal equipped gravel bike (I was!). I compared it to the $400 S-Phyre road shoe in a store. I honestly could not tell which shoe was lighter and they both felt equally as stiff. You do lose a boa lace and get a Velcro tab instead by stepping down but you also save $150. I would have paid $400 for a great shoe, so I feel like I got a bargain. I like a wide toe box and this shoe has one. I wear a 10.5 in Nike shoes and this shoe fits similarly. The only downside, which wasn’t an issue for me, is that it is slightly less comfortable to walk in than most MB shoes. This is a great race/training shoe. Have a good ride!

    Same thought here. Fantastic shoe at a great price. I ended up liking the fit so much, I ditched my road shoes I was using with my road bike, slapped some SPD pedals on and now use these shoes for road, cross, gravel and MTB. One shoe to rule them all! Thinking about buying a second pair for future.