I have R4's and they work fine, but I've not tried R14's so I don't know any better.....The r14 tires unfortunately are not in stock. From what I've been told it seems that the r4's are a longer lasting tire then r14s. Would the wait be worth it? 3 weeks for r14s to come in....
Worth waiting 3 weeks? I don't know, that's a long time to wait once you've made your decision to buy!