Recently I've been testing out the Shimano SH-RX800 (i.e. "RX8"), a high-end "gravel" shoe focused on multi-surface racing and adventure rides. I'd like to share some thoughts on the pros and cons of the RX8 shoes, and also some guidance about whether you should consider using them for cyclocross also.
The RX8 uses a carbon composite sole and one velcro strap per shoe, plus the distinctive BOA closure. It's a stiff, race-oriented shoe that won't hold back serious athletes. I'd use them without hesitation for competitive gravel races. Here's what I found during my test rides:
Shimano RX8 fit
I found the RX8 easy to setup and get comfortable on. I think it's worth noting that one of the things I like about Shimano shoes is the wider toe box; if you're used to Sidi or Northwave shoes that don't have much space in the width at the toes, you might like the Shimano fit.
I found the BOA adjustment straightforward and simple to use. Pulling the knob out, away from the shoe completely and immediately releases all the tension and is useful when putting the shoes on to quickly make them as loose as possible. Push the knob back in toward the shoe to put them in fine adjustment mode - while you're riding, twist the BOA knob toward the front of the bike to tighten, and toward the rear of the bike to loosen.
This is a key benefit compared to "ski buckle" fasteners on shoes, which can usually be tightened with one hand, but sometimes need two hands to loosen. As your feet swell on long rides, it's nice to be able to tighten or loosen the shoe one-handed with a quick twist of the BOA.
Shimano helpfully labels the sole with a stiffness rating, and the RX8 is labeled "10", an indicated of their performance focus. The sole is a carbon composite and feels plenty stiff for sprinting during my testing with basically no flex at all.
Shimano RX8 pros and cons
wide toe box
half sizes available (some models)
BOA makes fine adjustment fast and easy
odd colors/graphics not for everyone
not the best for running
The shoes use the common, standard Shimano SPD two-slot mounting for cleats. It's worth noting that the cleats come with the pedals, not the shoes. In addition to Shimano SPD cleats this mounting pattern will also accept cleats from competing pedals that use the same mounting pattern; Crankbrothers Eggbeater, Time ATAC.
The female portion that receives the cleat mounting bolts has a forward and rearward mounting position to choose from, useful for riders who want to experiment with the fore/aft adjustment.
There's also a helpful grid or marker lines printed on the sole, which greatly sped up the process of getting the cleats placed consistently on either side; and also makes future cleat replacement easier since it's easy to place new cleats in the exact same spot where the old ones were.
Two insole heights
My RX8's came with two spacers for the insole, a "medium" which was installed at the factory and a "high" option also included.
I don't feel that I needed more arch support, but the option is there for riders who want to experiment.
Should you use the RX8 shoe for cyclocross?
Maybe. The RX8 is plenty stiff and light for any serious racer. For gravel, I think, they're a no-brainer choice. If you're thinking about using the RX8 for cyclocross, there are a couple things to think about:
- The RX8 does not have removable / replaceable toe spikes. If you frequently race in cyclocross conditions demanding enough to require toe spikes for running, be aware there is no way to add them to these shoes. There is a rubber lug underneath the toe that approximates the function of a removable spike, but it's permanently molded into the sole.
- The footprint of the tread on the bottom of the shoe is fairly narrow, and not particularly stable for running. It's more of a pedaling shoe compared to a running shoe, something to think about if your local 'cross courses are running heavy.
What about SH-RX800 vs. SH-RX801?
Shimano does not label their products with model years. Instead, they increment the model number when products change.
The RX8 shoes I tested are the SH-RX800 model. Shimano recently released a small revision, the updated SH-RX801. Generally, the RX800 and RX801 models are nearly functionally identical, but there are a couple small changes to be aware of:
- The updated RX801 model now comes in half sizes,
- The RX801 has cosmetic changes (new colors),
- and the RX801 uses a more compact BOA knob, which in theory should make it less likely to hit accidentally.
There's also a second new shoe, the RX8R "rally" model. This one features a built-in knit "sock" that acts like a gaiter to keep sand or small stones out of the show. While this initially seems like a novelty, I can see how it might work on a sand-heavy cyclocross course (think Koksijde) where getting a bunch of sand in your shoes could be a problem.
Bottom line? Unless you need a half-size there's very little practical difference in performance between the "old" RX800 model and the RX801 refresh, so choose whichever comes in the color scheme you like.
The bottom line
Shimano RX8's is a fine choice for gravel and "adventure" riders who use dual-sided SPD pedals on rides that include pedaling, hike-a-bike, pavement, and dirt. If you're riding a drop bar bike on those types of surfaces, the RX8 is a good match.
These will set you back $275, which is not out of line with other brands, but isn't cheap, either.
Riders who do this type of riding but are less concerned about ultimate pedaling efficiency can check out the RX6, a a new shoe of the same style and similar features, but lacking the carbon sole.