What pressure are you running, and what is the actual inflated width of your 25s?
For reference, I weigh around 204#, I have 25mm 4000s on HED Belgium rims (23mm external), inflated width of tires is 28mm. I run upper 90s rear and low to mid 80s front. I don't ride a lot of chipseal, but this combo isn't terrible for me when I do. At 160# you could go lower pressure than me.