Completely agrre with everyone. Dog is out of control. I too have an old boy who has always been 'mouthy' - he is the sweetest, gentlest dog in the world, but it could frighten people who don't know him. So he doesn't get to run at people in that way. He is at heel walking quietly beside me if we meet anyone and if they want to talk to him - as they nearly always do because he is so handsome
- he is given the word 'gentle' and he then just laughs but doesn't mouth people.
It is up to you how you deal with the matter but I would agree that it might be best to talk to the owner quietly if you can get him on his own - and dismount from your bike well before the dog arrives so you aren't running the risk of beimg knocked over