Ism ps1 1the ps11 features the same sloped front arms as the ps 10 but it has slightly thicker 30 series padding and budget friendly crmo rails just like other performance short saddles the ps 11 has an upward slope at the rear providing superb hip support when your body is rotated forward in the aero position or an aggressive road riding position this tends to be preferred by athletes that dont move around on the seat excessively while riding it is also a top choice for triathletes