Boa Dial Replacement for RX8 Gravel Shoes

Ever since I got the Shimano RX8 gravel shoes 1.5 years ago, I have been using it on almost all my rides. This means that it is pretty well used.

Recently, I found that the rubber layer on the outside of the Boa dial was peeling off, due to wear and tear. It is still usable, but I also know that Boa provides a lifetime warranty for their Boa dials. This means that if the Boa dial is damaged or malfunctions, you can request for a free replacement.

Rubber layer on the outside of the Boa dial is peeling off.

Other parts of the shoe are fine, just that the dial is a bit worn out.

I contacted Boa to get a replacement, and it was sent out pretty quickly. It will be an equivalent Boa dial, although it may not have the exact same appearance.

It comes as a pair for left and right shoes. The difference is the rotation direction, which are mirror image of each other.

Left side (purple) is differentiated from the right side (red) by colour.

The new Boa dial has a black cover, which is different from the original RX8 dial which is transparent.

The Boa dial comes in two parts, one which is already fixed inside the black cover.

This part has 4 metal pawls on the outside, which will engage the ratchet on the inside of the dial that is fixed on the shoe.

Other than the replacement dials, a tool and new wire is provided.

Very detailed instructions, which I will need to follow very carefully.

The instructions for left and right dials are different, so take extra care to follow the correct instructions.

Using the tool, which is basically just a small Torx wrench to loosen the dial. I didn't realize that there was actually a small hole cleverly hidden in the middle of the dial!

This is the part from the left shoe.

The ratchet is fixed to the shoe, so it cannot be replaced.

Taking a picture here, to remember how the wire runs through the loops of the shoe, before I cut the wire.

Close look at the ratchet on the shoe, after the wire is cut. The screw tightens into the centre of the dial.

Putting the end of the wire through this soft loop is not easy, as the open end keeps getting stuck inside the soft fabric.

Putting the wire through these plastic guides.

I reused the old wire, but with a new plastic disc. Note that the wire is fixed to the disc only by some very clever knots. Follow the instructions carefully!

At this point, I was feeling rather happy with my work, as I have managed to replace the Boa dial on the left shoe, using the new purple discs and the old wire.

However, when I was moving on to the right shoe, I made a terrible mistake. Before the dial can be replaced, I need to cut the wire first. 

I accidentally cut the wire on the left shoe, which is the side which I have just replaced!

This was a really silly mistake. I needed to cut the wire on the right shoe, which still had the old dial. However, I went to cut the wire on the left shoe, which I have just replaced with the new dial. So much for a smooth replacement.

Luckily, I still had the new wire, which I did not use. It will take more work, but I still have the parts to replace both the Boa dials properly.

New dial on the left, old dial on the right. Different shades of red but the same design.

New dial is completely black, while the old one has a transparent cover. I like how the hole for tool access is cleverly hidden inside the letter "O".

New Boa dial installed! The black cover actually looks better than the original transparent cover.

New Boa dials! Feels somewhat like a new shoe again.

Other than the silly mistake that I made, the replacement was not difficult, just a bit tedious due to the small knots that I had to tie. I also took the chance to use a slightly longer wire length, so that the shoe can open a bit wider, to make it easier to insert the foot.

If your Boa dial is not working well, you can also contact Boa to get a replacement Boa dial.

Shimano RX8 Gravel Shoes - Cactus Berry

I have been using the Shimano RX8 gravel shoes for about 1.5 years, since end of 2019. As mentioned in that post, it is a perfect blend of MTB SPD cleats and road shoe aesthetics. It is lightweight, uses the convenient Boa dials, and feels really good. Other cycling shoes that I have used can be found here.

As with all shoes, it experiences wear and tear over time, especially with frequent usage during gravel riding. Therefore, I wanted to get another pair of it as a backup, or to use it in rotation, so that I can wash one pair while still using the other.

A new colour option was available, which is the unique Cactus Berry colour shown below. It is quite a weird colour combination, you either love it or hate it. I decided to try out this new colour, instead of getting the exact same camo silver colour.

New RX8 gravel shoes! This colour is also called purple/green.

I have never seen this Cactus Berry colour combination before!

Comes with sole inserts if you wish to adjust the foot arch height.

Reflective purple colour at the front

Uses the same single velcro strap at the front of the toe box area. Normally it will not need to be adjusted once set.

Uses the same two-way Boa dial at the side, for adjusting the fit around the top of the foot.

Colour transits to a pale green colour at the back of the shoe.

Inside of shoe is lightly padded. Feels comfortable and still maintains good power transfer.

This side of the shoe is completely free of features, to avoid interference with the crank arm and chain stay during pedaling.

See how the purple and green colour fades into each other. Someone told me it looks like a fish!

Here is how it looks on the foot

Looks stunning under sunlight, as it is reflective.

Definitely an eye-catching colour for a shoe!

Comparing side by side with the other pair

Front view

Side view

Top view

Side view

Bottom view. Looks completely different between the new and used pair.

The features and fit of the new shoe are the same as the previous pair, just that now I have two pairs that I can rotate and use. If you are considering getting one, check out the comparison and decide which colour you like! There is also plain black colour if you prefer.

Shimano RX8 Gravel Shoes - Silver Camo

As you may have realized from reading this blog that I am quite into gravel riding these days. The general idea of gravel riding is to ride light off-road trails on a road bike, and you can read a more detailed description here.

For gravel riding, most riders that use cleats will use SPD type of cleats, which are used for MTB and off-road riding. SPD-SL cleats which are for road bikes are hardly used for gravel riding, as the ability to walk properly is greatly compromised. Here is an article that I wrote some years back, but it is still as relevant. SPD-SL pedals and cleats also clog up more easily with mud, which will prevent you from clipping in normally.

I like to use SPD cleats and shoes, even on my road bike, as I want to be able to walk normally even when I am off the bike. I cannot do that if I use SPD-SL road shoes. Therefore, all my bikes either have a dual-sided SPD pedal such as the PD-M9020 or a SPD/flat dual sided pedal, such as the PD-A530.

The downside of using SPD shoes is that they are designed for off-road riding, which means there are large lugs on the sole, plus they use thicker and tougher material for off-road durability. This results in a shoe that is heavier and also looks too rugged for me.

I have previously used the RT82 Road Touring Shoe, which looks more like a road shoe but with SPD cleats. It works well, but it was discontinued a couple of years ago and I could not find a suitable replacement from Shimano.

After looking at other brands, I found a good looking one from Scott, which is the Scott MTB Elite Boa shoe. It looks less rugged, with nice colours and also has the Boa dial which makes it so much easier to put on or take off the shoe with one hand.

This year, the gravel dedicated groupset GRX was launched, and as part of the gravel setup, there is also a dedicated gravel shoe, the RX8 (SH-RX800). What makes it special is that it is a hybrid of road shoes and MTB shoes. Let's take a look and see what makes it so unique, and why I decided to get it.

RX8 Gravel Shoe!

Looks good! With a simple velcro strap at the front and a single Boa dial for adjustment, almost the same as the Scott MTB Elite Boa shoe.

RX8 logo clearly seen at the top. 

Very interesting silver camouflage pattern! Looks better in person and under sunlight. Very unique design.

Lots of holes for ventilation, we shall see how effective they are.

The Boa dial has a transparent cover, but I can't really see how the mechanism works.

The top part of the shoe looks very much like a road shoe, with the sleek and minimalist design with no seams.

SPD cleat mounting point, with printed lines that makes it easy to align the left and right cleats to the exact same position. The carbon sole stiffness is rated at 10 out of 12 which makes it really stiff.

Rubber lugs are small and of minimum size and height to reduce the weight of the shoe. Carbon shank extends throughout the whole shoe to make it stiff like a road shoe.

Shoes look really narrow but it fits well once the foot is inside.

There is an elastic strap that helps to wrap the top of the shoe over the top of the foot. However, it also makes it more difficult to wear the shoe.

The shoe weighs 284 grams, including the cleat nut (plate) but excluding the cleats and bolts. The claimed weight of 265 grams per side probably excludes the cleat nut weight.

Weight of the pair of cleats and bolts is 51 grams.

With the cleats installed. I fine tuned the adjustment on one side by repeatedly setting it and testing it, until I was happy with it. Then, I used the printed lines to replicate the setting on the other side.

With the cleats installed, one shoe weighs 309 grams.

In comparison, the Scott shoe weighs 416 grams, which is more than 100 grams heavier just on one side!

Comparing the weight, the RX8 is 25% lighter than the Scott shoe, which is very impressive. The total weight difference for a pair is more than 200 grams, which is quite a lot for just a pair of shoes.

That said, although I can feel the weight difference when holding the shoes, I can't really feel the weight difference when wearing it and pedaling with it. Let's do more comparison pictures to see how the RX8 differs from the Scott shoe.

Both are EU Size 42, but the shape appears to be totally different. Although the RX8 looks longer, it is just an illusion as the size is correct once the foot is inside. It fits my foot nicely with no need to increase or decrease the shoe size compared to my normal running shoes.

Both are using Boa dials that can be adjusted both ways for fine adjustments. The RX8 has two overlapping, asymmetric tongues, while the Scott has a traditional tongue in the centre, with the Boa wire passing through both sides symmetrically.

The RX8 looks just like a road shoe, compared to the Scott which looks tougher like a MTB shoe. The front part of the RX8 is also slightly higher to make it easier to walk with the stiff sole.

Rear view of the shoes. The RX8 has a stiff and supportive cup that fits my heel perfectly, to prevent it from slipping out even when the Boa dial is not fully tightened.

Front view of the shoes. The Scott has a "scuff plate" at the front to minimize damage to the shoe when walking off-road, while the RX8 does not, to save weight.

The soles look very different, as the RX8 has minimal lugs to simulate a road shoe, while the Scott shoe has many lugs spaced widely for more stable walking when off-road. There is an extra rubber layer in the middle of the RX8 to prevent the foot from slipping off the pedal if not clipped in.

The RX8 is a good looking gravel shoe, perfect for those who want to use SPD cleats, but want the appearance and low weight of a road shoe.

Highlights of this RX8 Gravel Shoe:
1) Lightweight, at over 100 grams lighter per side, compared to the the Scott MTB Elite Boa.
2) Easy to use Boa dial with two way adjustment possible.
3) Close fitting heel cup and tongue to cradle the foot securely.
4) Stiff carbon sole to improve power transfer, I can feel the difference when pedaling hard.
5) Great looking silver camouflage colour, and a nice road shoe appearance.
6) Appearance matches well with a road bike, but with SPD cleats for more walking convenience.

Issues I had with this RX8 Gravel Shoe:
1) Tongue of the shoe extends quite far back, making it a bit uncomfortable as the top of my foot is quite high. This makes the tongue "bite" into the top of my foot when the ankle is bent all the way up. Solution is to loosen the shoe slightly.
2) Elastic strap on the inside of the shoe makes it more difficult to insert the foot into the shoe.
3) Lugs on the sole can be placed slightly wider apart, to provide more stability when walking, as I have rolled my ankles a few times when the shoe rotated outwards when walking.
4) Stiff sole makes it less comfortable to walk compared to the Scott shoes.

Overall, this RX8 is a hybrid between road shoes and MTB shoes. It is mostly a road shoe, but with MTB SPD cleats and some lugs for ease of walking. This makes it lightweight (530 grams per pair), as it is just about 50 grams heavier than the top end RC9 S-Phyre road shoes (486 grams per pair). Weight is excluding any cleats or cleat nuts.

I am happy with this RX8 gravel shoes, as it has everything that I want in a cycling shoe. Now, I just need to get used to the stiffness of the shoe as I have not used a stiff road cycling shoe before, with my previous shoes all being MTB shoes that are more flexible.

Looks good on gravel and in the sunlight! 

Silver camouflage pattern blends in well with loose gravel.