answer: #Person1# and #Person2# decide to go to the concert by bike. #Person1# suggests wearing a round helmet. #Person2#'s new bicycle has problems with the brakes and the height of the saddle, so #Person1# helps to fix them.
documents: #Person1#: Are you ready to go to the concert?
  #Person2#: Yes. Should we go there by bus so we aren't late?
  #Person1#: Actually, why don't we go there by bike? We could get stuck in traffic if we travel by bus in rush hour.
  #Person2#: That's true. Cycling is good for our environment, too. Let me just get my helmet then.
  #Person1#: Is your helmet comfortable?
  #Person2#: Not really, but I liked the design, so I got it.
  #Person1#: Maybe you should think about getting a round helmet ; they're better.
  #Person2#: I'll think about it.
  #Person1#: Is that your new bicycle?
  #Person2#: Yes, my father gave it to me for my birthday. Do you like it?
  #Person1#: It's the newest 10 speed cycling mountain bike. These are really expensive!
  #Person2#: Nothing but the best from my dad. I like everything about it except for the brakes. They are a bit sticky.
  #Person1#: I can fix those for you. Is there anything else wrong with it?
  #Person2#: Well, my saddle is too low for me. Do you know how to change the height?
  #Person1#: That's easy. It's important to have the saddle high enough so that your legs can extend fully when you are on your bicycle.
  #Person2#: Is that why my knees have felt sore after every time I've ridden my bike?
  #Person1#: It's possible. Give me a minute and I can fix these for you and then we can go.