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SidiKaos Carbon Cycling Shoe - Men's

Sale 30% Off$227.49 $324.99

Item # SID004S

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  • Black, 39.0 ($227.49)
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Item # SID004S


For 2015, Sidi's orderly line of fastening options has been thrown into chaotic anarchy. The clear divide between models with the traditional ratcheting buckle we've been enjoying for decades and models with the sleek new Tecno-3 buckle has been shattered by the all-new Kaos Carbon Shoes, which bring the two fastening systems together with Sidi's versatile Millenium 4 outsole.

The Kaos shoes incorporate both a traditional ratcheting buckle at the top and the Tecno-3 wire dial for the mid- and forefoot. The Tecno-3 buckle operates like a quick-release hub: flip the lever up to open it, turn to tighten, and flip it down to lock your fit in place. The wire itself is both non-binding and non-stretch, so it adjusts smoothly without loosening over the course of your ride. Of course, one of the joys of owning Sidi shoes is mid-ride fiddling, so rest assured that both buckles are easily adjustable while in the saddle. The shoes also have the same amount of instep padding as Basso's own favorites, the Genius 6.6, so you can ratchet these puppies down with impunity.

The outsole is a nylon matrix shot through with carbon fiber, blending weight, stiffness, and price in a sole that's as ready to race as it is to spin through a charity ride century. It also resists warping due to humidity, heat, and age, so you'll be wearing the Kaos Shoes long after you've worn out and replaced the heel pad. If you've ever lost a buckle to a crash, then you'll also be happy to know that all of the shoes' hardware is also replaceable.

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


Cycling Footwear
35.5   4
36   4.5
36.5   5
37   5.5
37.5   6
38 5 6.5
38.5 5.5 6.5 / 7
39 6 7
39.5 6.5 7.5
40 6.5 / 7 8
40.5 7 8 / 8.5
41 7.5 8.5
41.5 8 9
42 8 / 8.5 9.5
42.5 8.5 9.5 / 10
43 9 10
43.5 9.5 10.5
44 9.5 / 10 11
44.5 10 11 / 11.5
45 10.5 11.5
45.5 11 12
46 11.5  
46.5 11.5 / 12  
47 12  
47.5 12.5  
48 13  
48.5 13.5  
49 14  

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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.

Unanswered Question

Hi, where are these made in?

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.

Are these spdcompatible?

These shoes are set up for the SPD-SL road cleats but if you are talking about the SPD mountain cleats those will not work. Any cleat with the 3 hole adapter.

These shoes are set up for the SPD-SL road cleats but if you are talking about the SPD mountain cleats those will not work. Any cleat with the 3 hole adapter.

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.

Do they make Mega sizes anymore? Looking for 46.5 Mega in fluo

Best Answer

The Genius 6.6 Vent is the only Sidi we have available right in a wide fit. Let me know if you have any other questions. btowery@backcountry.com

Are these available in a size 42 Mega for wide feet?

Best Answer

Second that question! Mega size please?