Our first review of the Trek FX+ 2 was our circuit test, which you can learn more about in the graphic above. This allowed us to get a feel for the bike’s HyDrive 250W rear hub motor and test the performance of its cadence sensor.
Without motor support, the slim frame and minimalist character of the FX+ 2 immediately came to the fore. Many of the e-bikes I’ve tested are huge and heavy, a fact that quickly becomes apparent when the motor does nothing to pull its weight. This is why the PAS 0 lap in our Circuit test can feel terrible. However, with the FX+ 2 it became relatively easy. The bike’s 40-pound frame is comparable in weight to a non-electric model on the heavier side, so it still took some work to complete this lap, but I was pleasantly surprised at how much energy I had left , as I rounded the last corner.
Over my subsequent three laps, I noticed that the bike’s small 250W motor really underscores its intention of being a bike first and an e-bike second. To compare again with other e-bikes I’ve tried, much stronger rear hub motors create the strong feeling of being pushed from behind. This feeling exists on the FX+ 2, but only slightly and when the engine engages for the first time after starting from a slow idle or stop. Once up to speed, the bike’s torque sensor and motor work together to deliver a remarkably natural ride that I can only compare to a mid-engine. The motor intervention is subtle and sometimes difficult to notice until you realize that you have just climbed a hill that you normally would not have been able to climb. This is in stark contrast to many more powerful rear hub motors, which obviously seem like they’re taking full control.
The FX+ 2 also stood out from many other e-bikes I tested in another way: its PAS system. You often see pedal assistance systems with five input levels. It’s also common for at least one of these levels to feel relatively ineffective. The FX+ 2 cuts the fat here by focusing on just three PAS settings, all of which are functional, varied and intuitively tuned.
The graphic above illustrates this point perfectly. It’s relatively rare that we see such a linear progression between settings on an e-bike, and while it makes sense for some to deviate from this pattern, we’d like to see it more often. To get to the heart of what the data and linear graph mean, if you increase the PAS level on the FX+ 2 you will get exactly the performance increase you would expect from the engine.
If I’m honest, that’s not surprising. Trek has been making bicycles since the 1970s and e-bikes since the early 2000s, and is also a huge company with plenty of money for research and development. They have the customer base to encourage them to do things right, as well as the experience and development team to make it happen. Further evidence of this can be found in Our other Trek e-bike reviews. Let’s first return to our review of the Trek FX+ 2.
Due to its reliance on driver input, the FX+ 2 is capable of achieving high speeds even at low PAS settings. Since this is a Class 1 e-bike, this means the motor contributes up to 20 miles per hour. With some work I was able to achieve speeds close to this limit in PAS 1, and this has now become easier in PAS 2 and 3. Here at EBR we often say that some e-bikes can make you feel superhuman, and I think that’s definitely true for FX+ 2 in PAS 3.
The FX+2’s motor performance can be optimized somewhat by pairing the bike with the Hyena Rider Assistant app. We’ll look at this in more detail later, but for now just know that the motor output of the three PAS settings can be adjusted while the bike is stationary. PAS 1 has a range of 1-33% of the total power (rated power) of the engine. PAS 2 can be set anywhere between 34 and 67% of total power, and PAS 3 rounds out the range between 68 and 100%. I played around with it a bit and the difference is relatively small for the already unremarkable engine, but can make a difference of a few miles per hour.
