Ok, so here's a question for ya'll I'm starting Traveler out biking with me because he needs to get used to the bike, the commands and everything. He LOVES it and all I do is down the street and back on the grass and some of me walking next to the bike with him. He gets the biggest kick out of me being able to go as fast as him. Now, my question is this-how far is too far and how much is too much for an almost 5 month old puppy that adult size is around 45 pounds in a breed not known for any hip or joint issues. I of course let him set the pace and would stop if he showed just an inkling of wanting too but I'm sure in his case I'm going to be the one stepping in and saying enough is enough because I believe he would go go go. Now, I'm not talking about focing him to run at all and he would be on grass at all times, setting the pace at all times and a lot of slow trotting. But my main question is, when should I stop him? How much is enough? 1 quarter of a mile? More? Less? Opinions?