Powerfly FS 4
E-bikes are the hot thing right now and what we have here is the newest electric MTB from world famous Trek. What, you thought they weren’t in the game?

Trek's 2021 Powerfly FS 4 e-MTB Will Take All the Abuse You Can Throw at It

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Known as the Powerfly FS 4, this e-bike is the newest absolute monster from the Trek lineup. But aside from being new and all, it also boasts the best this team has to offer.

Now, what you get when you look to spend that extra $4,600 you have lying around in your wallet is an absolute drool machine. If we take a look at the frame, we can see it’s a bit different than other designs we’ve seen.

It all starts with the use of something called Alpha Platinum Aluminum. We’re not sure if it actually includes any platinum in the actual construction - it could be a name for this class of aluminum frames the team pushes out. That’s not to say it’s not magical enough. The frames composed of this stuff rival the weight limits of frames made from carbon fiber. Just to get an idea of how light it the frame is, the bike comes in with a weight of 54.88 lbs (24.89 kg) in medium size.

Wait a minute, that can’t be right: an e-MTB that barely tops 50 lbs? Okay, I could get used to this. I guess when I bought my first bike, my instinct to go with a Trek seems to have been a wise decision, as today I still have life-time warranty on the frame. I just don’t think the guy who stole it knows that. Actually, I think he did. That’s why I sit alone at night and sometimes wonder where ‘she’ could be.

Powerfly FS 4
To add more appeal to the bike, the frame is also prepped for complete internal routing of all cables and lines. But this seems to be standard nowadays. As for the down tube, here we find an integrated battery that can be easily removed for charging.

Speaking of battery, on this beauty we find a Bosch Powertube 500, that’s good enough for... well, that depends. Do you really think with all the biking expertise Trek has, it would simply be able to tell you how far you can go with an electric bike? Well, it can: before you look into buying your FS 4, click here to check out the range calculator. You will be surprised by what is possible with this bike.

As for the motor to help overcome whatever K2 throws at you, Bosch continues their presence with a Performance CX line motor with 250W rating and 85 Nm (62 lb-ft) of torque with a peak speed of 20 mph (32 kph). An FSA Bosch crank is also there to complete the Bosch works.

I nearly forgot the most important part, the Purion controller, a piece of hardware that adds magic to the motor and battery, helping them perform at optimum levels.

Powerfly FS 4
For shifting, Trek chose to go with the never-fail Shimano Deore shifters and derailleur. And for braking, we find trusted Tektro with 6-bolt 203-mm (8-in) rotors. Stopping power will be the last thing on your mind with this set-up.

As for suspension, the front includes an SR Suntour XCR 34 with air spring and 100 mm (4 in) of travel - a bit tight for my taste. But the rear features a Suntour Edge R 190 mm x 45 mm (7.5 x 1.7 in). That's more than enough to compensate for the apparent lack of travel on the front.

Honestly, all I want to do now is just get on one of these. I know for sure I won’t regret it as I never have any of Trek's creations.


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