Road Bike Tire Test: Specialized Cotton TLR 28

The Cotton TLR is Specialized's first cotton tubeless-ready tire and the spiritual successor to the (tube-type) Turbo Cotton, which we have known since 2016. Specialized has waited and skipped the first generation of cotton tubeless-ready tires, likely because they had some downsides. The Cotton TLR is therefore a significant step forward for Specialized and comes with a second-generation easy-to-inflate 320 TPI casing, vulcanized tread, and a Dual T2/T5 Gripton compound.

If you're into (tubeless-ready) cotton tires, the past year has been great, as we've also seen the release of the Bontrager Aeolus RSL TLR (read our review) and Cadex Aero Cotton (read our review), which all come with greatly improved ease of inflation and air retention capabilities. Together with the Vittoria Corsa Pro range, Challenge's broad lineup, and Specialized's new Cotton TLR, there's now ample choice in this segment.

The Cotton TLR is a true racing tire, as evidenced by the "Racing Only Tire" label on the box. To keep weight and rolling resistance down, racing-only tires usually have less tread thickness and less puncture protection, so make sure you pick the right tire for the job. Even though this is a racing-only tire and we didn't find any mention of Specialized's BlackBelt anti-puncture layer, our test results still show decent (tread) puncture protection.

Specialized also follows the wider tire and rim trend, and the Cotton TLR is now available in 28, 30, and 32 mm sizes, which are close to the rated size on 21 mm internal-width rims. That new 21 mm rim sizing means the actual size on smaller rims is quite a bit smaller, and the 28 mm is similar in size to the 26 mm tires of the past. We've tested the 28-622 size, and our full test results are available below.

The Specialized Cotton TLR is the fastest-rolling tubeless-ready cotton racing tire that still offers an acceptable tread thickness and tread puncture resistance. When we compare the Specialized Cotton TLR to the "gold-standard" Vittoria Corsa Pro (read our review), we see that the Cotton TLR is the better tire for rolling resistance and wet grip, making it the better racing tire. The weakest link is the sidewalls, which are much easier to puncture than nearly all tubeless-ready tires we've tested to date.

We see a very clear optimization for the 21 mm internal rim width, resulting in a very small size on our 18 mm test rim. We also do not recommend the Cotton TLR for rims wider than 21 mm, as the tread width is relatively small and you'll be more vulnerable to sidewall punctures on already weak sidewalls, or to riding on the sidewalls when combined with very wide rims (22mm+).

We can see why Specialized optimized for the 21 mm rim width, as their entire road bike wheel lineup comes with a 21 mm internal width, and we assume they'll stick with this rim width for the near future. If you're all-in on Specialized equipment, the new Cotton TLR is the best performance upgrade for ultimate racing performance.