Trek Powerfly FS9 Equipped review

The FS9 is top of Trek’s four-model Powerfly Equipped range of electric bikes designed to combine practicality for commuting with the off-road fun of the best mountain bikes.

Its specification, which combines a long-range 625Wh battery, a Bosch Performance 250W motor and a full-suspension setup with powerful four-piston brakes, is sending a message that it won’t flinch when the going gets tough.

Trek Powerfly FS9 Equipped specifications

At first glance, all that off-road tech seems at odds with the bike’s more sedate features, which include integrated full-length mudguards, a kickstand and built-in lights.

Trek’s promo video shows the sort of shopping trip we all wish we had, with a route mixing road and scenic dirt track, and I approached my first ride on the Powerfly hoping this could be the commuter bike of my dreams.

The strong Bontrager Line Comp 30 wheels, shod in chunky 29x2.4in tyres, the SR Suntour Zeron 35 120mm suspension fork and RockShox SID Luxe Select+ rear shock are pulled from the mountain biking world.

It’s a combination that would normally be compromised by its weight for commuting, but in pairing it with an 85Nm motor so powerful as to be unbothered by extra heft, Trek has managed to optimise the Powerfly for the commute.

And who wouldn’t want comfortable, grippy tyres, powerful brakes and plush suspension?

That suspension was something that gave me pause for thought before testing – can a full-suspension machine with a mountain bike heritage be efficient on the road? Yes. Keep reading to find out how.

Trek Powerfly FS9 Equipped geometry

Trek Powerfly FS9 Equipped battery life

Not that I have experienced problems with battery range, regularly riding 70-90km, including over 1,000m of climbing, and arriving home with plenty in the tank.

There are four modes – Eco, Tour (eMTB Lite), eMTB and Turbo – and even on longer routes, I didn’t have to drop to Eco to preserve battery life, riding mainly in Tour mode with short boosts of added power.

Trek Powerfly FS9 Equipped ride impressions

I’d not used this fork before and it surprised me – in a good way. It's stiff enough to support the bike’s weight, it doesn’t bounce when you’re pedalling hard on the road, yet it sucks up the chatter of poor tarmac.

Transitioning to forest tracks, it smooths the ride so you barely lose speed over rocks and roots.

The rear shock is unusually positioned behind the seatpost, but is protected by the full mudguard. It absorbs the bumps but, as with the fork, doesn’t bounce. It plants the back wheel into the ground in a way that feels secure and maintains grip right through corners.

That security and control is underlined by the Shimano XT four-piston brakes, which are strong enough to slow the weight of the bike quickly and smoothly without locking.

The Powerfly FS9 Equipped seems to love going fast in a straight line the most, and the distances I’ve ridden on a mix of roads and tracks are testament to its comfort and ride appeal.

It does, however, have limits on more technical terrain.

I’ve ridden it over the same terrain I use for testing the best electric mountain bikes, and there is no comparison – it doesn’t have the handling finesse for tight, twisty stuff.

If you have the skills, yes, you’d do it, but probably not in quite the style you’d like.

Sweet-spot pedalling helped by smart modes

The 10-51t gearing range is huge, but still I found myself succumbing to the temptation to stick to a few of the lower gears and default to switching between power modes.

It’s a habit that doesn’t get the most out of you or the motor, so I played with the onboard app and discovered it gives a readout for optimum cadence, turning green when you get it right.

That’s all to the good, though the weight means it’s not a bike you want to be caught out on without power. Moving between modes is quick and smooth, the motor picking up exactly where it needs to.

My only gripe is that when it tops out at 26km/h, the cut-off feels abrupt and the bike slows rapidly before kicking back to life. It’s not a seamless experience.

Accessories for the win

The mudguards have good clearance and keep off most of what gets thrown up, even from wet, muddy tracks.

In fact, I came to appreciate all the commuting-specific accessories more than I expected. A kickstand may not feel that exciting, but once I used this rather than propping the weighty ebike against a wall, I was converted.

The built-in lights are powered by the battery, so there’s no reason to get caught without working illumination. The sturdy rack will bear up to 25 kilos and is compatible with most panniers.

Trek Powerfly FS9 Equipped bottom line

The Trek Powerfly FS9 Equipped is an electric bike that makes you want to ride more – it allows you to take the more interesting routes less travelled on your commute and have fun on forest tracks at the weekend.

It would also be ideal for touring on long-distance tracks such as King Alfred’s Way in the south west of England, given its range, comfort and load capacity.

Embrace its niche and you’ll get the best out of this bike, and it could well get the best out of you as a rider – if you can afford it.