The Brooks Cambium Saddles are a massive, tectonic-plate-shifting departure from the venerable saddle maker. Why? Because they're not leather. Brooks made its name over the last century making the best leather saddles on the planet. Even as other saddle makers adopted microfibers, foams, gels, and other modern materials, Brooks remained steadfast. Now, though, they've developed a rubber/canvas construction technique that offers all the benefits of their leather saddles in a weather- and vegan-friendly package. The shell of the saddle is a natural rubber, which is vulcanized to a cotton canvas topper. The break-in period for a Brooks saddle is nearly as legendary as the saddles themselves, and the Cambiums are a bit different, though special care should still be taken. The rubber needs very little breaking in -it should be quite comfortable out of the box. The canvas topper, however, is a bit rough, and will abrade Lycra shorts quickly and severely. For this reason, we recommend breaking this saddle in on a more casual bike (one that you'd wear jeans on) before putting it on a bike that will see Lycra time.