[racket] Difference in speed accessing fields of a struct with gen:equal+hash

I added gen:equal+hash to a struct type and noticed that accessing
fields of the struct got slower, even though I never used equal? or
hash functions. Is this expected? And if so what is the cause of it?

#lang racket

(struct foo (x) #:transparent)
(struct bar (x) #:transparent
        #:methods gen:equal+hash
        [(define (equal-proc x y recur)
           (recur (bar-x x) (bar-x y)))
         (define (hash-proc x recur) (recur (bar-x x)))
         (define (hash2-proc x recur) (recur (bar-x x)))])






(define N 10000000)
(define f (foo 3))
(define b (bar 3))
(for ((j 5))
  (time
    (for ((i (in-range N)))
      (equal? (foo-x f) (foo-x f))))
  (time
    (for ((i (in-range N)))
      (equal? (bar-x b) (bar-x b)))))

My timings showing a 10% slowdown.

cpu time: 296 real time: 296 gc time: 0

cpu time: 334 real time: 334 gc time: 0

cpu time: 297 real time: 297 gc time: 0

cpu time: 340 real time: 340 gc time: 0

cpu time: 303 real time: 302 gc time: 0

cpu time: 340 real time: 339 gc time: 0

cpu time: 292 real time: 292 gc time: 0

cpu time: 327 real time: 326 gc time: 0

cpu time: 291 real time: 291 gc time: 0

cpu time: 323 real time: 322 gc time: 0