Fuji SL 1.5 review

Super light by name and nature

BikeRadar score4.5/5Find prices on Bicycle Blue Book

With the UCI entertaining the possibility of doing away with the 6.8kg minimum bike weight, it’s no surprise many manufacturers continue to push the realms of how light it's possible to go.

With bike brands competing to see who can make the lightest bike, Fuji's 4.95kg SL 1.1 has set the bar pretty high (or low). Our size medium sample SL 1.5 shares its 695g frame as that flagship model, albeit with a different paint job. Additionally, the considerably smaller price tag results in heavier  components, but this is still a full Dura-Ace equipped ride.

But just how does it ride? Is the SL just a novelty act that's all about showing off über-light weight, or does it keep pace with its competitors?

Smooth inside and out

The secret to the SL’s feathery prowess is in the carbon layup. Introduced with the earlier Altamira, Fuji uses a 'High Compaction' technique to create tubes that are smoothly finished inside andout. This sheds unnecessary material, and distributes resin more evenly during manufacturing, producing a stronger and lighter frame.

High end components and a lightweight frame and fork tip the scales at 6.4kg: high end components and a lightweight frame and fork tip the scales at 6.4kg
High end components and a lightweight frame and fork tip the scales at 6.4kg: high end components and a lightweight frame and fork tip the scales at 6.4kg

Fuji saves weight by limiting bonded joints to the chain- and seatstays

For the SL, Fuji has also built the frame in just two pieces, only bonding the seat and chainstays. True carbon monocoque frames are quite rare, with most being cast in sections and then bonded together to create a finished product — adding extra material and weight.

Explosive performer

Tipping the scales at 6.4kg, the SL 1.5 is seriously light and snappy. Changes in speed are explosive and the bike begs to be ridden out of the saddle. The jump is similar to the BMC Teammachine SLR01, a bike that's rarely matched in terms of acceleration.

On smooth paved roads the SL rolls along with minimal feedback, though there is a bit of high frequency buzz that makes it to the touch points when things get rough — it definitely takes its toll after a few hours in the saddle. That said, wide 25c rubber and dainty ovalized seatstays take the sting out of larger hits, but remember this is a race bike, so comfort comes second to speed.

Replacing the Altamira as Fuji’s flagship lightweight racer, the SL sees a few changes in geometry with more bottom bracket drop, a shorter wheelbase and head tube, and a slightly longer trail figure (less fork rake).

Despite its weight, the frame is seriously stiff throughout: Fuji claims the SL is 9% stiffer in the head tube, 11% stiffer in the bottom bracket, and 18% stiffer in the fork than the Altimira. Numbers aside, we weren’t able to detect any hint of flex in the frame with the power down.  While the bottom bracket shell is not massive, the chainstays, seat tube and down tube all become quite boxy as they converge at the cranks, providing a solid pedaling platform.

The bottom bracket is boxy and stiff, but not overly large: the bottom bracket is boxy and stiff, but not overly large
The bottom bracket is boxy and stiff, but not overly large: the bottom bracket is boxy and stiff, but not overly large

The SL doesn't boast a massive bottom bracket area, but it does the job well

The front end of our 54cm sample sees a 135mm head tube and Fuji’s new I-Beam reinforced fork, which features an internal support that runs the length of the legs. We’re not sure if the SL’s front end is really 18% stiffer than the Altamira, but we can say it's suitably solid. The stiff fork combined with the common 73-degree head angle transmit every bit of steering input to the pavement for sharp and precise handling, especially at speed.

A tasteful level of bling

Arguably the most immediately striking features of the SL 1.5 are its gold accents against the matt-black frame. Gold bikes bring mix opinions among the BikeRadar staff, but the SL 1.5 features (in this tester's opinion at least) just the right amount of bling. Internal cabling adds to the clean aesthetic, and the frame accepts both mechanical and electronic drivetrains.

With two versions above the 1.5 in the SL range, it still features a full Shimano Dura-Ace mechanical build, high-end alloy wheels and carbon finishing kit.

Beyond the bolt-on glitz and glam, the frame sees a chainsuck protector on the driveside chainstay and built-in chain-catcher to guard against off-chance bad luck (or poor derailleur adjustment).

While not as flashy as the electronic version, Dura-Ace mechanical arguably sets the benchmark when it comes to shifting performance and efficiency. Fuji has wisely combined a 52-36t crankset with a 11-25t cassette for a gear range ready for any situation, though for riding in the hills we wouldn’t mind a 28t cog at the back to further the SL’s climbing prowess.

The PF30 bottom bracket shell offers decent crank compatibility, and the high-quality Praxis conversion bottom bracket didn’t cause any trouble during our testing – not that we expected it to.

The 733 aluminium clinchers are and awesome wheel set which add the the snappy fun character of the sl: the 733 aluminium clinchers are and awesome wheel set which add the the snappy fun character of the sl
The 733 aluminium clinchers are and awesome wheel set which add the the snappy fun character of the sl: the 733 aluminium clinchers are and awesome wheel set which add the the snappy fun character of the sl

The 773 alloy clinchers add to the snappy demeanor of the the SL 1.5

Oval’s 733 aero aluminium clinchers were one of the biggest surprises encountered in our testing. Weighing in at 1445g they are playfully snappy and blisteringly fast. With a 22.5mm rim width, they spread the 25c Vittoria Rubino rubber nicely. The hoops are also tubeless ready (you’ll need rim strips, valves and sealant), and are 33mm deep with a slight aero profile. The aero shape offered a subtle advantage at speed but due to its low profile, remained completely unaffected by sidewinds on the flats, and being relatively lightweight didn’t hurt on the climbs either.

The wheels turn on sealed bearing hubs with a six-pawl alloy freehub featuring an ‘anti-bite guard’ to ensure individual cassette cogs don’t dig in (we dig it). You also get Oval-branded internal cam skewers, which have plenty of clamping force.

As per usual Dura-Ace brake calipers and pads provide confident stopping and modulation. There’s a good reason for why they’re consistently looked at as the standard-setters in rim brakes.

Quality finishing kit

While Fuji decided not to outsource the remainder of the finishing kit to bigger name component brands, the Oval Concepts parts do not sacrifice on quality.

The Oval 707 3D forged alloy stem employs what the brand calls ‘Optimal Stiffness Construction’. It’s claimed to better distribute stress from the bars to the stem without adding weight or reducing strength.

Oval claims the six-degree clamping angle created by their stem provides better clamping force with less torque: oval claims the six-degree clamping angle created by their stem provides better clamping force with less torque
Oval claims the six-degree clamping angle created by their stem provides better clamping force with less torque: oval claims the six-degree clamping angle created by their stem provides better clamping force with less torque

There was something weird about tightening the top two stem bolts all the way before torquing the bottom two

Utilizing the ‘Mesh Fit bolt pattern’ Oval says to tighten the top two stem bolts to 5Nm first (closing the gap), and then torque the lower bolts creating a six-degree tightening angle, which is said hold the bars better with less force. This new clamping method is something we’ve also seen recently from PRO components and Canyon.

At the rear we see an Oval R700 with chromoly-Ti hollow rails and 27.2mm carbon seatpost. With a pressure-relieving cutout and moderate padding, the perch is wouldn't be my personal choice but may well find favour with other riders.

The verdict

Here’s the hard part of this review: assigning the SL 1.5 a star rating. This bike is awesome; it’s lightweight, playful, fast, and most importantly fun to ride. It’s not the most comfortable race bike we’ve ever ridden, but the sensations add to the overall riding experience — it never feels lifeless underneath you. The components are top notch, it looks great, and all in all we struggled to find fault with the complete package.

While it was a near fit for me, and what I look for in a bike, it’s not for everyone. Just like how you wouldn’t buy a Lamborghini to run kids to and from soccer practice, you shouldn’t buy the Fuji SL if you're don't have good reason to be choosing a high-performance ride. This bike is aggressive in every way, and those who aren’t after something long and low should not be blinded by the eye-catching numbers on the scale.

For those who are looking to do some serious racing (whether official or not) though, the 1.5 SL isn’t terribly hard on the wallet at £3,399 / $4,740 / AU$6,999 and packs a true speed punch to compete with many priced well above it.

Colin Levitch

Staff Writer, Australia
Originally from Denver, Colorado, Colin now resides in Sydney, Australia. Holding a media degree, Colin is focused on the adventure sport media world. Coming from a ski background, his former European pro father convinced him to try collegiate crit racing. Although his bright socks say full roadie, he enjoys the occasional mountain bike ride, too.
  • Age: 25
  • Height: 175cm / 5'9"
  • Weight: 70kg / 155lb
  • Waist: 81.3cm/32in
  • Chest: 90cm/35.4in
  • Discipline: Road, mountain
  • Preferred Terrain: Tarmac mountain climbs into snow-covered hills
  • Current Bikes: BMC TeamMachine SLR01, Trek Top Fuel 9
  • Dream Bike: Mosaic Cycles RT-1
  • Beer of Choice: New Belgium La Folie
  • Location: Sydney, Australia

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