I've got a 1990s Trek 1400 with 105 brakes. When I apply the brakes they feel soft. I replaced the cables being careful about routing, etc. with no improvement. The calipers themselves visibly flex when the brakes are applied hard. Nowhere near the solid feel I get with the v-brakes or cantis I'm familiar with. Is this normal for caliper brakes? This is my first bike with caliper brakes since the Schwinn Varsity I grew up with in the 70s.