Sidi T3 Carbon Triathlon Shoe Review

author : hoffsquared
comments : 1

These shoes would be good for athletes looking to upgrade from a shoe with a nylon/plastic composite sole to a good carbon composite sole.

Manufacturer: Sidi

Product: T3 Air Carbon Triathlon Shoe (Women’s)

Mileage Tested: 325 miles 

Hours Tested: Approximately 30 hours, daily 18 mile round-trip commute, training rides, and 1 olympic triathlon race.

How I Ended Up Buying This Shoe:

I’ve been wearing an entry-level (very, very entry-level) road shoe ever since I decided to ride clipless. I settled on a low end shoe since I did not want to invest a lot of money in road shoes if I ultimately couldn’t learn how to ride clipless. These shoes have served me well over the past four years and 10,000 miles later. But I started having foot issues during my races this year. I attribute this to my well worn bike shoes made with a nylon composite sole and the fact that I could actually flex the shoe with my hands. My feet would start hurting a bit towards the latter end of an Olympic bike course and this, in turn, starting affecting my runs.

So I decided on a big shoe upgrade for my last race of the season. A big upgrade meant going with a carbon composite sole. I narrowed down my options by doing some basic research and by seeing what was available to try on in local triathlon and cycling shops.

I ended up trying on Pearl Izumi’s Tri Fly IV Carbon, Louis Garneau Tri-Lite Carbon, and Sidi T3 Air Carbon shoes.  The staff, in one shop in particular, were very helpful in showing the different designs of each shoe and what a proper fit felt like.

Quick tech specs:
  • Eleven Carbon/Composite Sole injected carbon fiber sole reduces weight without sacrificing stiffness and efficiency
  • NEW AIR perforated Triathlon-specific upper has a plush, brushed interior with minimal seams for sock-free comfort, and is now vented for air flow and water drainage
  • Women-specific last/foot-form and narrow SIDI Heel Cup for perfect fit
  • Notched top strap opens away from the drive train
  • Large heel loop for fast transitions
  • SIDI Heel Cup
  • Replaceable heel pads

I am so glad I tried on shoes rather than ordering them online! They all fit a little bit differently and only the Sidi’s seemed to fit me just right. I have a pretty ‘standard’ foot. It’s not too wide and not too narrow. Most shoes I try on fit very well so I was surprised at how differently each shoe felt. 

I could not get the Pearl Izumi’s and LG’s to fit snug enough in my mid-foot area in a size that was long enough for my foot. So they either gave me enough toe room but were too loose mid-foot or fit well in the mid-foot but were too short depending on the size I tried on.

The Sidi’s fit just right. My foot feels snug yet not constricted. My toes aren’t squashed and my heel is firmly in the shoe. My only concern was how fast I would be able to get them on and off since they were snug and the closure was a bit different from the other shoes.

Lesson learned – trying on high end bike shoes with the help of knowledgeable staff is critical! I had been leaning towards the LG’s prior to my fitting sessions. I know I would not have been completely happy with how they fit.  

It was with a big gulp that I had the store put on the right cleats. Once the cleats were installed they were not returnable!

I expect these to be the last pair of triathlon bike shoes I will ever need to purchase.

Initial Impressions: 

What can I say – these shoes are sleek, fast, and high-tech looking. When I put them on, my foot feels secure and ready for transmitting power to the pedal.


I instantly noticed a difference the power of my pedal stroke with these shoes on.   It’s unclear to me if this is due to the carbon composite sole or just to the fact they are much stiffer than my seasoned nylon composite sole – that is would any new shoe have felt a lot different?

Regardless, I feel more powerful on the bike overall. It seems that all my energy is being transferred to the pedal. In my old shoes, especially on hills, I could tell there was some flex in the mid-foot area and lost power with each pedal stroke. My Sidi’s, on the other hand, are stiff and transfer all the power I can muster. 

In addition, my feet just never gave me any issues. My feet were cool. My toes and pressure points felt comfortable.

Overall, I feel the shoes helped my last race effort (or at least did not negatively impact it as my old shoes did).

Sizing/Ease of Installation/Setup:  

This shoe has a “Technical Information” manual. The manual covers the specific for all Sidi’s carbon cycling shoes. There were detailed instructions on how to install my Shimano SPD cleats. However, I had the store install the cleats since installation involved doing something with a reinforcement plate in the shoe. This took them about 10-20 minutes.

Sidi provides some help on shoe sizing on their website:

Quality of the setup/installation instructions:

The Technical Information manual is quite detailed and covers all shoe parts including cleat installation and buckles and other closure systems (for regular road shoes).

Sidi also has FAQs regarding their shoes on their website:


The shoes look sleek, fast, and high-tech. As an added bonus, they even make my feet look small!      

Ease of Use:

There are two Velcro straps to deal with. I only have to deal with the strap nearest the ankle since I have the forefoot strap set where I want it.

Although snug, I can get into and out of these shoes quite quickly. In my recent race with them, I posted the fastest swim-to-bike transition and the 2nd fastest bike-to-run transition in my age group. This was one area I was concerned about.

Quality of construction:

These are well made and Sidi pays attention to detail. Just about anything that can break or wear out is replaceable.


I love how this shoe fits - snug but not tight.


I feel like I could wear this shoe on very long rides although I haven’t yet. 


I am hoping these hold up pretty well over the years. I will use them for races, training, and, perhaps, bike commutes on nice days.


These shoes are one of my bigger investments besides my bike.   They are also one of the most important components of my triathlon gear. I am glad I have them and do feel they are a good value in light off all the other things we buy to race at a FOP age group level.

In the scheme of things, I do think they will be the last pair of triathlon shoes I buy.

Overall Performance:

These shoes have performed great so far. I’d recommend anyone currently looking for new triathlon carbon cycling shoes to give these a look. But, more importantly, I’d make sure to try on several different styles to make sure you find the right shoe.


  • Sleek looking
  • Stiffness in carbon composite sole
  • Sidi's reputation for producing long lasting shoes
  • Comfort


  • I will need a shoe cover for cold weather
  • I cannot wear thick socks in cold weather

Closing Summary (who is it good for, etc):

These shoes would be good for athletes looking to upgrade from a shoe with a nylon/plastic composite sole to a good carbon composite sole.

Note: I plan on buying a Sidi carbon road shoe to replace my regular nylon commuter road shoe. They will be the last cycling shoe I ever need to buy!

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date: October 25, 2013