You can unlock the Endless Endo trophy in Trials Rising on any track. You will simply need to break and then lean forward so that you are balancing on your front wheel for 10 seconds.
Once raised in the air on your front wheel, you will have to keep your back wheel and the riders head in line to maintain the balance point. Make adjustments with the right stick as you feel the weight begin to shift forwards or backwards.
You can see the tutorial video from University of Trials below if you are struggling to control the endo for 10 seconds.