I don't know enough about the TQ motor to explain how drag like this could occur.
In any case the EXe should not feel like "a real dog" at 50% assist. 150W assist is quite a boost.
It sounds suspiciously like it may just be a psycho-somatic phenomenon where your legs and brain sense the change in assistance. Do you feel the same thing when you go from Turbo to Trail or from Trail to Eco? It's a common sensation with all ebikes.
If it does turn out to be a problem with the TQ motor we'd like to hear more about the diagnosis.
Update on motor drag: Trek has done some testing and the supposed drag has not been "psycho-somatic". They are replacing the motor. Thank you Trek. Excited to ride the TQ motor the way it was designed to!
Lower shock bolt:
I have a nasty clack clack sound coming from my motor / lower shock mount area. I have read through all the lower shock bolt posts and also followed the service bulletin for the mounting hardware. I am not sure the mounting hardware is the issue here.
The lower shock bolt is a stock standard mass-produced machine bolt you can buy from any hardware shop. Shoulder diameter 7.9mm and 7.85mm on the thread. Bolts are generally used to resist vertical forces or from clamping together. In shock mount applications bolts are subjected to lateral forces (pulling perpendicular). This means the bolt diameter and mounting holes needs to be closely matched. I spoke to the Betterbolt guys and they make M8 shock bolts at 7.96mm, exactly for that reason.
After 2 months of riding, the lower shock mounting holes (in the frame) is currently measuring 8.2 and 8.24mm respectively. I will keep an eye on it, but once you have play it can only go one way if side-loading forces are applied.
I ordered a Trek Bolt M8 x 1.25 x 64mm bolt (W511147) as
@njatherton suggested and filed the head down to 13.5mm. The bolt is a little long, but I added a 2mm washer on the head side. But this bolt also measures 7.9mm diameter.
I am concerned that with the already enlarged mounting holes on my frame (±8.2mm), no amount of bigger bolt finding or electrical tape will close the gap in the long run. I can try and use a 6mm bolt, with some form of nylon bushing, but I feel this is really too much hacking on a 2 month old bike. The bolt diameter and mounting holes needed to be matched much closer than what it was out of the factory. Using a mass production machine bolt with broad tolerances (south of 8mm) also didn't help.
The new Trek Fuel EX uses this type of stock off the shelf bolt too, and I think this is really corner cutting from Trek. Other (older) Trek bikes uses proper shock bolts designed to closely match the mounting hole.
There is no play when I cycled the suspension in my garage, but once I have square edged hits it goes clack clack clack. I really hope its not the lower shock bolt hitting the metal of the mounting holes due to the excessive play in that area. The dealer is baffled.
Maybe the sound is not the bolt, maybe its in the motor, who knows. But the big gap between mounting hole and shock bolt is a concern in the long run.
