The FLO 77 AS – A Deep, Fast, & Stable Wheel

A few weeks ago we wrote an article that highlighted the FLO 64 AS and discussed its versatility as a cycling wheel. That article was prompted by one of the most frequent questions we get asked: “What wheels are best for me?”  

This time, we are going to highlight the FLO 77 AS. As I have stated before, all of the wheels designed at FLO are like children to me. New to our lineup is the FLO 77 AS. Before 2020, we had a FLO 90 which had a rim depth of 94.7mm. While being a very fast wheel, it was also a bit of a wild child when handling the front wheel in crosswinds. The deeper a front wheel, the more difficult it is to handle in strong or gusty winds. When developing the FLO 77 AS, we considered the handling depth, but speed was something on which we were unwilling to compromise. Read below to learn more about how we reduced the depth of the wheel by close to 20mm, made it faster, and why it may just be the best wheel for you.

A general rule of thumb is that you want to ride the deepest carbon wheels you can handle. When you upgrade from stock wheels to FLO wheels, in general you’re saving about 10 minutes. However, when considering a shallower FLO wheel—like the FLO 64 AS—there is a time savings difference between that and the FLO 77 AS of less than 30 seconds over 100 miles. Considering all other variables are the same, there is not a lot of room for error. So, what would make you lose time on a deeper wheel? The biggest reason is a change of your body position.

Picture yourself riding a set of deep wheels, in an aero position, in your sweet spot of winds less than 20mph. Now, the wind starts to pick up and you start getting blown around, and are not so comfortable. To stabilize, you come out of the aero position. Since your body is the largest producer of drag on the bike, you quickly start losing more time than you would if you were to pick a shallower wheel that allowed you to stay in the aero position indefinitely.  

As a front wheel, the FLO 90 wasn’t the best fit for a lot of people because it caused many to come out of the bars when riding. So we asked ourselves, “How can we make a fast, deep wheel with better stabilization that allows riders to stay in an aero position longer?” In order to accomplish this, we did three things:

1. We widened the rim.
2. We optimized the rim around larger tires.
3. We used our proprietary algorithm and searched hundreds of shapes to optimize the depth and width ratio of a rim. 

The result was a 76.6mm deep rim. This rim is faster and more stable than our FLO 90. Now, being shallower and better able to handle crosswinds, it opened up the FLO 77 AS as a choice for many more people when deciding on a front wheel, and we now have a wheel that is manageable for most everyone.

Reasons you would not want to consider a front FLO 77 AS are:

1. You are a very small and light rider. < 5’4” and 120lbs
2. You are very sensitive to crosswinds. 

Just like our FLO 64 AS, the FLO 77 AS has excellent vibration dampening due to the deep carbon profile acting as a leaf spring. The sidewalls of the rim flex to absorb vibration. The flexing happens since the sidewalls are a bridge between the spoke bed and the tire. As vibration travels from the tires to the rim, the sidewalls absorb the vibration, making the ride smoother and increasing your grip on the road surface.

Reducing the rim nearly 20mm allowed us to reduce the weight of the wheel from roughly 2,200g to roughly 1,700g. This is a significant savings and brings the wheel very close to our FLO 49 AS and FLO 64 AS, which is something we’ve not been able to do in the past with our FLO 90. 

The FLO 77 AS has become a serious contender in our lineup for everyday riding, training, and racing. The lower profile produces a much more stable front wheel when compared to our FLO 90, and also offers a large weight reduction of more than 500g. Due to our advances in rim shape and our understanding of rolling resistance, we were able to optimize the FLO 77 AS to be faster than our FLO 90. If you are looking for a deep and stable wheel to be as competitive as possible, make sure you place the FLO 77 AS high on your list of choices for a carbon wheel.