Road Bike Tire Test: Cadex Aero Tire 28

Warning: Our tests and measurements indicate that the CADEX Aero Tire has a tread that is too small for this tire size and poses a safety risk. The tread is just 21 mm wide, so you'll be riding on the sidewalls even at modest lean angles. With extended sidewall wear, there's a risk of a tire blowout during cornering, which we don't want to see happen to you. This problem will be even more exposed on wider rims, which this tire is designed for (22.4 mm Cadex wheels).

This is the first time we have issued a warning about a tire, but after 12 years and 500+ tire tests, we feel this is the right thing to do. We don't want to think about what happens when a tire blows out during hard downhill cornering. To put the 21 mm wide tread into perspective, 28 mm rated tires usually come with a tread width of at least 28 mm, with 30-32 mm as the average, and some tires even go as wide as 38 mm.

When we look at the other CADEX tires we've tested, we see that the 28 mm Aero Cotton (read our review) has a tread width of 30 mm, and the 25 mm Cadex Race Tubeless (read our review) even comes with a tread width of 31 mm. Both those Cadex tires have a wide enough tread, and we believe Cadex has gone too far with the aero optimization on the Aero Tire, resulting in a tire that can only be used safely on straights.

The previously smallest tread we measured on a 28 mm-rated tire was found on the Michelin Power Cup TLR (read our review), which has a 26 mm-wide tread, and we advised that tire to be used only on rims with a maximum width of 17 mm. We visually inspected the sidewall contact of the Cadex Aero Tire during our wet grip edge test, with the tire mounted on a 19 mm internal-width rim at a 35-degree lean angle; the sidewall contact was roughly 3-4 mm. When we add the 3-4 mm per side to the tread, that would come to roughly a 28 mm-wide tread, which we advise as the minimum for 28 mm-rated tires.

To avoid questions about the measurement and the tread possibly being wider than the visible area, we measured the thickness of the tire right along the visible end of the tread, and it was just 0.60 mm, indicating the sidewall starts right along the visible end of the tread.

If you want to stick with Cadex tires, we recommend skipping the Aero Tire unless you know exactly what you're doing. We recommend the Cadex Aero Cotton (read our review) as an alternative, a tire we rated 5 out of 5 "Highly Recommended" just a couple of months back.

In addition to the safety issue of the tread being too small, we also found that inflating the tire on our test rims was impossible without a compressor and the removal of the valve core. We can't remember the last time we had to remove the valve core to inflate tires, but it's been several years. Most tubeless tires have advanced significantly, making inflation much easier with new bead designs.

The Cadex Aero Tire's performance in our tests isn't spectacular either. Rolling resistance doesn't come close to the competition's levels, negating any potential aero benefit. Weight looks like a plus, but, for obvious reasons, it isn't a fair comparison. The tread's puncture resistance is decent, but the sidewalls are extremely weak and thin, making the small tread an even bigger concern.

Performance in the wet grip tests is slightly above average, with the edge test still coming in quite strong, even though a large part (about 1/3 of the contact patch) of the test surface is in contact with the sidewall.

Due to sub-average performance in our tests, a small tread combined with thin sidewalls that is a safety concern, the impossibility to inflate without a compressor, and the high price tag, we recommend you stay away from the Cadex Aero Tire.

If you're interested in Cadex tires, go with the Aero Cotton (read our review) rather than the Aero Tire.

Compare the Cadex Aero Tire and Aero Cotton on our comparison section.