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Sidi - Kaos Carbon Cycling Shoe - Men's

Sidi Kaos Carbon Cycling Shoe - Men's

51% Off
$159.95 Original price:$324.99
Changing the size selection, or changing the selected color after selecting a size, may change the associated price

Item #SID004S




Kaos Carbon Cycling Shoe

The Kaos shoes are built upon the Millenium 4 Outsole, which is a nylon matrix infused with carbon fiber. The mixed compound is resistant to heat and humidity, ensuring that your soles will outlast replacement heel pads and buckles, which are available separately.

The uppers are a breathable synthetic leather lined with a microfiber to keep your feet cool and dry. Unlike leather, the synthetic will not stretch and provides consistent support for your feet. To secure the shoes, Sidi placed its ratcheting buckle at the ankle sewn to a wide band to reduce pressure. At the forefoot are two Techo-3 buckles. These feature a twist and tighten mechanism that allows micro-adjustments. Both are easy to adjust in the saddle.

  • Road Cycling 3-hole cleat compatible
  • Millenium 4 Outsole
  • Ratcheting buckle and Techno-3 wire for added security

i did not find them to fit larger

  • Familiarity: I returned this product before using it
  • Fit: True to size
  • Size Bought: 42

I am sitting here with 2 genius shoes, a 7 and a 5??, a genius 10 and a Kaos in size 42. All are great shoes. However, except for the genius 10, they all fit the same. I did not find any difference in the fit between the Kaos and my genius's.

I can't comment on how they work as they have to go back. They black looks like patent leather and not sure how it will break in. The ratcheting buckle and tecno-3 buckle work fine.

I love my genius 7's but size 42 is SLIGHTLY too tight on my right foot and my next to little toe hits the side of the toe box. I don't like how the 42.5's fit so I have lived with them for years. But I love my Sidi's and thought, based on the reviews that the Kaos would fit that smidgen larger but they don't.

I am at this point planning on keeping the genius 10's. They do seem to give me the extra room. However, I am not in love with all the wire systems. I will miss my ratcheting and velcro closures...

My Spring/Fall Shoe

  • Familiarity: I've used it several times
  • Fit: Runs large
  • Size Bought: 43

Believe it or not, I bought these because they aren't as well ventilated as a couple of other shoes I own, and I wanted something for cooler temps. These fit a bit large (with an insole, I usually take 43.5 and these are 43) but these fit fine with an insole. The shoes they replaced (also SIDIs I'd had since 2013!) had velcro and the buckle ratchet, but I like the boa better, as the velcro on the old shoes eventually stopped holding well. I've read several reviews stating the upper material seems "cheap". I disagree... it is the same material found on SIDIs more expensive shoes (like the Wire). The soles are plenty stiff... as stiff as my Wires and my S-Phyres, both of which are top of the line. Overall, these are very nice shoes at a great price. I'd been eyeing them for some time and I'm very glad I finally pulled the ticket.

Too narrow for me

  • Familiarity: I returned this product before using it
  • Size Bought: 48

Unfortunately these were just too narrow for me. For reference - I have an old pair of Sidi Genius in 47 MEGA that I can wear with a thick sock. I also have pair of Giro Techlace in 48 that will be worn with a thin wool blend CEP sock. The Kaos in a 48s that I tried was just too narrow.

Fit aside they also look / feel like a fairly cheap shoe. Am convinced that you can do much better for the $300 price point. Even at $200 they are likely worth a pass.

Finally back on Sidi's

  • Familiarity: I've put it through the wringer
  • Fit: True to size
  • Size Bought: 43.5

I have always loved Sidi shoes & am very glad to be riding in them again. I had been riding Shimano racing shoes but they just never seemed to fit quite right. The Sidi's fit my narrow heel & foot so much better. I really like the Techno-wire closure for the lower foot. It is quick and easy to get them to feel just right on my feet.

Much better fit for my narrow foot

  • Familiarity: I've used it several times
  • Fit: True to size
  • Size Bought: 46.5

Sadly, Sidi doesn't make their narrow line any longer. But, for my US 12B foot, this was a huge improvement over the Shimano shoes I had before. The Boa adjuster tweaks the fit very comfortably, leaving only a little side-to-side play. The sole is thicker than my other carbon shoes with no flex. Others have reported some discomfort during the first few rides - a "break in period" I guess. I didn't have any problem at all and was very comfortable from the first wearing. It being winter, I can't comment on how well the shoe breathes in the summer. I can say that I'm comfortable with toe covers above 32F and full shoe covers below that. Lastly, every component of the shoe can be replaced if it wears or breaks. This was a huge selling point for me as I like well-made products that last.

How do these compare to the Sidi narrow? I have an extremely narrow foot and the narrow Genius 5 is the only shoe I’ve found that will fit. Are these comparable?

Best shoe ever

  • Familiarity: I've put it through the wringer
  • Fit: True to size
  • Size Bought: 45.5

Buckle is better than boa on sidi. I have both and this is my favorite

Glad to be back in Sidi's

  • Familiarity: I've used it several times
  • Fit: True to size
  • Size Bought: 43

I purchased these shoes last fall after too many years in some ill fitting shimano's. I love the fit & finish of Sidi's and they are very comfortable even on long rides. The adjustability while riding is great. I have kind of goofy feet & these fit well and I know that they will last for years. I have other pairs of Sidi's that I bought over 10 years ago and they are still in great shape and fit well.

A little time will telI...

  • Fit: Runs large
  • Size Bought: 45

First general impression of the shoes was fantastic. Look and general feel was what I expected. I should have yielded more to the comments about the shoe running a bit large. I believed mine to be large so I called the Gearheads. Once again they were patient and gave me several suggestions and we developed a next step plan. So my review of the shoes is incomplete. I will update once I've had a little time in the saddle. My review of the Gearheads and their service is complete. These folks remain top notch and knowledgeable and are the reason CC is the only on-line cycling store I support.

Sad about Sidi

  • Familiarity: I returned this product before using it
  • Fit: Runs large
  • Size Bought: 45.5

I too have worn Sidi shoes for yrs. I should have believed the reviews on size! I ordered the same size I currently wear (45.5) and the new shoes were not only much longer, but wider as well. The material was starting to "bunch up" as I tightened the buckles. I was also a bit disappointed in the feel and look of the material. It felt very "plastic" like. Not sure I would have kept them even if the fit was right. I was expecting a better "feel" for a shoe that is supposedly worth $300.

SIDI - consistency

  • Fit: True to size

I always find SIDI to be the most consistent in build and size from generation to generation. This shoe here is the Ultegra of Shimano, it has just about everything DA has but half the price. The material will stay white for long time and there is very little fabric that will turn yellowish over time around the ankle. With a little soap the fabric can be kept flat white for a long time also. Just like every other SIDI you don't buy new ones because you wore out the old ones, these things last. I have SIDI's from 10 years ago still look great. Money well spent.

Everything I expected and wanted

  • Fit: True to size
  • Size Bought: 46.5

As a long-time Sidi user, I wanted a more customizable fit than I had had with the Genius 5 - which I loved and used for 10 years. I have a high instep and a "bump" on the top of one foot, so sometimes the mid-foot straps would generate uneven pressure and occasional discomfort on longer rides. The Techno 3 ratchet system seemed a great idea, so first I tried the Wire Vent Carbon shoe. Because of my high instep and the Techno 3 top buckle which restricted my ability to open the shoe fully, I had trouble getting into the shoe. I then tried the Kaos, which uses the more traditional caliper buckle on the top and the Techno 3 ratchet system for the mid-foot and toe. As I had hoped, the Techno 3 system applies an even pressure across the entire top of the foot - even where my "bump" has caused discomfort in the past. The ratchets can be dialed tighter or looser with great precision. The top caliper buckle enables me to open fully and get into the shoe easily, and when tightened it holds the top of the foot snugly and comfortably. The upper is supple and quite comfortable as well. The sole is stiff allowing for an efficient transfer of power. My only unfulfilled wish is that the Kaos doesn't have the Adjustable Heel Retention Device that the Wire Vent Carbon had - a terrific feature. All in all however, this is a great shoe, and it delivers everything that I had hoped for in a high quality (and, yes, expensive) road shoe.

Nice looking shoe but had fit issues

  • Fit: Runs large

The "Kaos" is aptly named, for the chaos that ensues as the tongue saws into your ankle during your ride.
Try this on before you install the cleats. My experience may a fluke but I had some issues with discomfort that I have not experienced with any other Sidi shoes. To begin, the polished appearance is nice. The fastening system is also really nice. The top position is tightened with a user-friendly ratchet buckle. Below that, a single wire-type dial can be rotated to tighten the 2nd and 3rd position, which is convenient (2 adjustments rather than 3). However -- the tongue felt sharp and high, and it cut into my ankle. I thought it might break in after a few rides, but no - I had to wear thick socks to protect my ankle from the sharp tongue. The overall fit felt deeper than my Genius 6.6, and the sole I think is also thicker than my 6.6 that I was replacing, so I had problems getting comfortable with these, and I ended up switching to another shoe.

Your supposed to cut Sidi tongues. Any retailer should have told you that. There is even instructional videos online

Really?? Thanks Anthony K. I've been wearing Sidi many years now and this was the first time I had a problem. This is also the first time I've heard about a need to cut the tongues. I'll research it a bit further.

I highly recommend these shoes.

  • Familiarity: I've put it through the wringer
  • Fit: True to size

My carbon road shoes have 4K miles on them, so I thought I'd move them to wet weather shoes and buy a replacement for routine use. After some research, I thought that the Sidi Kaos had great value for the construction, manufacturer reputation, and, frankly, looks - for a great price. I ordered a 44 and a 45, because that's what I wear depending on the manufacturer. These run a little on the larger size, so the 45's were perfect. First ride was ~50 miles and they were comfortable, stiff, and very easy to adjust for the perfect cleat placement on the ride.


Cycling Footwear
36 3.3 4.8 2.8 22
36.5 3.7 5.2 3.2 22.4
37 4.1 5.6 3.6 22.7
37.5 4.5 6 4 23
38 4.9 6.4 4.4 23.3
38.5 5.3 6.8 4.8 23.7
39 5.7 7.2 5.2 24
39.5 6.1 7.6 5.6 24.4
40 6.4 7.9 5.9 24.7
40.5 6.8 8.3


41 7.2 8.7 6.7 25.3
41.5 7.6 9.1 7.1 25.7
42 8 9.5 7.5 26
42.5 8.4 9.9 7.9 26.4
43 8.8 10.3 8.3 26.7
43.5 9.2 10.7 8.7 27
44 9.6   9.1 27.3
44.5 10   9.5 27.7
45 10.4   9.9 28
45.5 10.8   10.3 28.4
46 11.2   10.7 28.7
46.5 11.6   11.1 29
47 11.9   11.4 29.3
47.5 12.3   11.8 29.7
48 12.7   12.2 30
48.5 13.1   12.6 30.4
49 13.5   13 30.7
Sidi recommends following the procedure below to ensure that you choose the right size.
Measure your foot by following these steps:
1. Put a sheet of paper on the floow with the short side against the wall.
2. Put the sole of your bare foot on it with the heel pressing against the wall.
3. Mark the point in front of the tip of your longest toe on the sheet of paper.
4. Measure the distance between the margin of the sheet of paper where you placed your heel and the point where you made the mark. Always round up the measurement to the nearest mm.
You may find that your right and left foot are different lengths. Always measure both of them and use the longest measurement as your reference.
If you are undecided between two sizes after consulting the table, Sidi recommends that you opt for the larger size.