Simple thing to do, but requires repeated typing. The only thing it does is move from channel-a to channel-b. This function is implemented in https://github.com/gerritjvv/fun-utils

clojure async channel bridge

(require '[clojure.core.async :refer [chan go >! <! >!! <!!]])
(require '[clojure.core.async :as async])

(defn chan-bridge
  ([ch-source map-f ch-target]
   "map map-f onto ch-source and copy the result to ch-target"
    (chan-bridge (async/map map-f [ch-source]) ch-target))         
  ([ch-source ch-target]
    "in a loop read from ch-source and write to ch-target
     this function returns inmediately and returns the ch-target"    
      (go 
         (while (not (Thread/interrupted))
              (if-let [v (<! ch-source)]
                    (>! ch-target v))))
      ch-target))

;; test

(let [ch1 (chan 10)
      ch2 (chan-bridge ch1 (chan 10))]
           
           (doseq [i (range 5)] (>!! ch1 i))
               
           (prn (reduce + (repeatedly 5 #(<!! ch2)))))
;; 10

(let [ch1 (chan 10)
      ch2 (chan-bridge ch1 inc (chan 10))]
               
      (doseq [i (range 5)] (>!! ch1 i))
               
      (prn (reduce + (repeatedly 5 #(<!! ch2)))))
;; 15

core.async has the pipe function for this:
http://clojure.github.io/core.async/#clojure.core.async/pipe