I have heard from a lot of user water leaking problem from original BTA system, the cause is than when you keep the pipe long (similar like it is come), while you are riding the tip leaves to down and leaks.
But according my opinion is good to have a long pipe because make easier the process to drink.
So, I would like to share my own solution to this problem explained in detail in the file enclosed, the idea is just to install a magnet to keep the tip of the pipe in a position that does not alloy the leaks.
I have tested my idea for more than 200 Km and the leaking dissapear at all
If you have to implement it, go ahead and enjoy the ride
Trek Speed Concept Gen 3.pdf