Sidi Genius 6.6 Carbon Road Shoe Pro Review - by Russell Clark
  • Patented full carbon sole
  • Heel Security System prevents power robbing heel lift
  • Vented, reflective heel cup
  • Soft instep closure system w/Ultra SL buckle reduces numb spots
  • High-security Velcro won't shift or slip
  • Sizes 38-48
  • MSRP - $475

The Sidi Genius 6.6 lies second in Sidi's road shoe hierarchy. Built on the 'Sidi Full Carbon Sole', which is the same platform found on their flagship shoe: Ergo 2 Carbon. With two 'High Security Velcro' closures on the instep and the and 'Caliper Buckle' ratcheting, top enclosure.

Sidi is one of the most aesthetically appealing cycling shoe brands I've seen. When the Genius 6.6's landed in my hands, I was almost reluctant to get them dirty. They are beautifully made: flashy, classy, and robust. However, as soon as I was home, I buttoned up a new pair of cleats for my ride the very next day. I enjoyed breaking them in for a couple weeks before racing in them in local road races and criteriums.


In my opinion, the outstanding feature of the 6.6 is the Full Carbon Sole. This sole has a unique feature in that it is compatible with the LOOK KEO memory cleat. This will be a great benefit when replacing cleats. Sidi claims that there are other soles on their shoes that are thinner/more compliant. I believe it. These shoes proved to be very rigid and efficient in comparison to other all-carbon road shoes I have ridden: Shimano, Specialized, DMT.

I also found the Lorica upper to be quite supple very comfortable. The mesh ventilates the foot well, too, in that on the hottest days during use (approaching triple digits), my feet never felt overheated. With regard to the Lorica and mesh, I found that they noticeably show dirt. Fortunately, they come clean with a soft finger-brush and mild soap.

The retention system works almost flawlessly. The High Security Velcro closure straps keeps the foot secure, and is easy enough to use, even at speed. If you, however, prefer to wear shoe covers or booties, making adjustments to the instep enclosures is virtually impossible. Riders with concern to this issue should consider one of the other two upper tier shoes. What's more is that the Caliper Buckle has a tendency to rattle on rougher roads. Initially, I thought it was a loose screw on the cleat, alas, it was not…thank goodness! The buckle is a little tricky to get used to, at first. But, later was a no-brainer. What I would like to see, is a buckle system that more closely regulates the tension release action. When reducing the tension on the Caliper Buckle, it seems that the action wants to jump about 3-4 "notches", on initial release. I would have found liked a buckle system that would allow about ½ that release. Lastly, regarding the enclosure system, I found the Heel Cup System (HCS) to be a perfect fit for my somewhat-narrow heel.

Reverting to some of the features I previously mentioned, I was most impressed with the rigidity of the Full Carbon Sole. On the first ride, I could feel a significant difference between the 6.6 and the previous all-carbon sole shoe I had ridden the day before (2007 Specialized S-Works), which were only 2-3 months old, themselves. The soles on these shoes were RIGID! Now, I have to mention that the first all-carbon road shoe I ever wore was a first generation, top-of-the-line Shimano, carbon sole road shoe. These shoes were so stiff, that after a couple months of hard riding, I developed a bit of tendonitis. Not so with the 6.6. They are stiff, but compliant…perfect for big miles, big hills, big races.

I think it took about 3 weeks for the shoes to fully break-in, for me. I am a chronic over-tightener when it comes to shoes. Now, after a couple of months riding in these shoes, I have no discomfort whatsoever…even after 5 or 6 hours in the saddle. Walking is a bit of an issue, with the LOOK KEO cleats. Even when the LOOK patented covers are applied, they can be tricky for the novice rider negotiating a coffee shop, garage or local bike shop. Adding a bit of width to the heel-pad would be a big help in walking stability.

Enough of that…back to the riding!

I was reluctant to put a pair of shoe covers on these beauties, because they are so blingy. The white/cromo color option suits just about any kit on race day or on a club run with your mates. Nevertheless, they garnered many compliments from my riding pals and gave me added incentive to ride.


Real World Experience
I am really impressed with the Sidi Genius 6.6 Carbon. After a spin around the block or two, a couple short rides to fine-tune the cleat position, I decided that I would need an additional footbed for a perfect fit (I have a low instep). I was then, off to the mountains.

On my favorite afternoon loop, there's an 8 mile climb that I use to test my fitness or state of fatigue. On this climb, there are a few steeper sections before flicking left and rolling along a mountain ridge for about 13 miles. During the first few mountain loops wearing these shoes, I noticed that I was pushing a bigger gear than normal…which I attributed partly to the "new shoe high", but more so to the added efficiency and rigidity of the 6.6's.

This shoe meets all the needs of a fashion conscious, road rider who enjoys efficiency in an easy-to-use shoe for long or short rides. I, myself, am a slave to cycling fashion. That being said, I like to keep my gear clean, tidy and well aligned. One day, post-ride at my favorite coffee shop, I noticed that one of the straps to the Caliper Buckle system was longer than the other. After a very brief inspection, I noticed that they are removeable/replaceable/adjustable. AWESOME! I, then adjusted the strap to perfect length…matching the other shoe.

Bottom Line
I love the Genius 6.6 shoe. I think it could be a near-perfect shoe with a little more attention given to the buckle system. For a guy like me who loves to wear shoe covers year-round, however…I would consider the other two, based on ease of adjustability of the fore-foot retention alone.

  • Ride efficiency - direct power/energy transfer from shoe to pedal with extreme comfort
  • Fit - versatile adjustability in the heel-cup, buckle, buckle strap for a perfect fit
  • BLING! - incredible style with that certain Italian flash
  • Buckle - rattling noise on less-than-perfectly smooth roads
  • Buckle - poor regulation of tension release
  • Longevity in cleanliness - ok, they're white. A little soap & water does the trick.

4  bottle
¾ bottles…near perfection.
4  bottle