Ridley Fenix SL Disc review

A Belgian take on the endurance bike category

Our rating 
3.5 out of 5 star rating 3.5
GBP £2,999.99 RRP | USD $4,650.00

Our review

A Classics-worthy frame with great acceleration, overall stiffness, and good looks, but the finishing kit won't suit everyone
Buy if, Classic endurance geometry is your flavour, overall stiffness is a must, and Belgian traditions warm your soul
Pros: Stiffness and handling
Cons: It’s no featherweight and for the price it’s got stiff competition
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Ridley’s full-carbon Fenix SL Disc fits the classic endurance bike mold, with a high-performance twist. For riders looking for that all-day-long bike that doesn’t balk when the power hits the pedals, the Ridley Fenix SL Disc is worth a look.

Combining a stiff frame with endurance geometry, Ridley aims for the high-performance end of the endurance spectrum with the Fenix SL Disc. While many competitors aim for a plush feel, Ridley turns the other direction.

The Fenix SL Disc, at least under my guidance, feels like a bike meant for powerful riders — the type of rider who would never use the word ‘comfort’ in front of another.

So whom exactly does this bike speak to? I’m looking at the former racer. There’s not enough time in the day to train, the front-end position isn’t as aggressive as it once was and a bit of compliance is welcomed, but acceleration and racy handling are still a must.

Lastly, the 18.69lb / 8.48kg load won’t bother a former racer, as it’s likely lighter than whatever they used to toe the line with.

The numbers tell the story

With all that extra room, why spec a 25mm tire? Regardless, slap on 28mm or even 30mm
Thomas McDaniel / Immediate Media

For me, geometry is the one thing that brings clarity to an otherwise cloudy mess of modern bike designs. Race this, aero that, do-it-all-thingy, call it whatever you want but the geo numbers tell a story.

The wheelbase, head tube angle and front-center of the Fenix SL mean you could point it down the road blindfolded and you’d still be headed in the right direction. It’s an endurance bike.

From that base, with modern tires and wheels, comfort can be fine tuned for your preference. With the specced 25mm tires, it ended up not really riding that smoothly, but with 28mm (29.5mm measured) rubber mounted it was a delight to pedal.

Contact points

Good looking bar tape is great as long as it’s not a compromise on comfort or performance — a bit of padding goes a long way on an endurance bike
Thomas McDaniel / Immediate Media

While on the ‘things I’d do differently’ high horse, I should include the contact points. I’m a bike fitter and I take issue with product teams not giving the saddle, handlebar and bar wrap the attention they warrant.

The 4ZA Pro saddle is almost certainly too narrow for anybody to sit on for hours at a time. I lasted 20 minutes before heading back to swap it out. At its absolute widest it’s 12.5cm, but realistically it’s in the 7–8cm range for available seating due to its curvature. For reference, I’ve fitted teenagers with sit bones that wouldn’t fit on that, let alone an adult.

The bar tape might look good in a catalog, but it’s not got any comfort via thickness or gel. And it pretty much fails at the sweat test.

If the bike is designed for long rides, put a perch worthy of such a task — this 4ZA Pro is definitely on the narrow side
Thomas McDaniel / Immediate Media

Also, the handlebar goes from 31.6mm to super narrow, but why? Why taper? Why not create a nice plush space for the hands? It’s an endurance bike, but even if it were an altitude, or race bike, it still fails.

If this were a fit client’s bike, it’s almost a certainty that the saddle and bar tape would immediately be replaced, if not the handlebar too. This adds a $150 minimum to the price tag before even pedaling, and that’s a shame.

But if that’s not a big deal to you, then let me offer some positive takes on the Fenix SL.

On the plus side

With a wide bottom bracket and intimidating chainstays, the Fenix has endurance compliance without sacrificing pedal performance
Thomas McDaniel / Immediate Media

First of all, the bike is a looker. Far too often endurance bikes have anaemic fork legs, with large down tubes, head tubes, and bottom brackets, resulting in an unbalanced appearance.

We all like light bikes, but with a few grams to spare Ridley gave the Fenix SL some nice industrial design lines. But it’s not all muscle fortunately; the dropped seatstays and offset seatpost keep the bike from feeling harsh, as it may visually appear.

In short, the designers gave the bike a smooth transition from speed to comfort from front to back. Overall the visual appeal doesn’t come at a cost of the bike riding like an endurance bike should — smooth and comfortable.

It’s got good overall plushness (with 28mm tires mounted) and the stability expected of an endurance bike. Even on pothole-ridden roads the bike showed its class by keeping me relatively comfy. And it’s not given away pedal performance as a trade-off for keeping riders fresh. The Fenix SL Disc is more of a have-it-all kind of bike.

Not a value leader, but not too far off

The Fenix SL Disc takes a stand against the spindly tubes typical of endurance bikes
Thomas McDaniel / Immediate Media

The endurance category is crowded, and for good reason. In my experience at retail, fitting and researching riders, the geometry of endurance bikes is far more suitable than most (Trek H2 aside).

And no, Johnny crit racer, I’m not talking about you and your slam-that-stem fetish. I’m talking about the masses — the ones who pay retail prices, the ones who keep the shop lights on.

As such, the first three endurance bikes I researched had matching spec at slightly lower prices than the Fenix SL Disc Ultegra at £2,999 / $3,800. Competitors are also bringing proprietary compliance systems, which may or may not suit your style.

The Trek Domane SL 6 Disc comes with a similar spec and IsoSpeed front and rear at £3,000 / $3,499. Specialized has the Roubaix Expert Ultegra, armed with its new compliance system front to back and electronic shifting at £3,500 / $4,000. And given the attention Trek and Specialized place on contact points, well, it’s tough to compete.

Last but not least, Cannondale offers the Synapse Disc with Ultegra and SL crankset at £2,699 / $2,999. 

It’s really difficult to wrap my head around the value of the Fenix given the likely replacement of contact points. In addition, its five-year warranty is competing against other brands that offer lifetime guarantees. 

A love of Belgium?

The Ridley Fenix SL Disc is clearly an all-rounder, with a geometry-induced endurance attitude.

Here in the rolling hills of the middle-country, it goes up and down without resisting. It flicks easily from side to side when out of the saddle, and it’s free from any sluggish front wheel flop when wiggling up the steepest inclines.

When letting it go fast and loose on the descents, I was stoked to see the fork didn’t flex to and fro during hard braking efforts.

As any long wheelbase will do, it can be difficult to get the bike to dive into a turn. However, once its trajectory is altered, it holds a line quite nicely thanks to good axle-to-axle stiffness.

The Fenix SL is definitely one of those ‘pedal like you stole it’ kind of bikes. So if you like your endurance with a sprinkling of André Greipel, this machine delivers.

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If the look and feel of the bike falls within your preference pallete, or if you just love the Belgian cycling tradition, then go for it. But if bang for the buck is your priority, then there are other options waiting for you.

Product Specifications


Name Name, 0, 10, Name, Fenix SL Disc Ultegra
Brand Brand, 0, 20, Brand, Ridley

Brakes Brakes, 2, 0, Brakes, Shimano BR-RS805 Flatmount
Cassette Cassette, 2, 0, Cassette, Shimano 105, 11-28
Chain Chain, 2, 0, Chain, KMC X11
Cranks Cranks, 2, 0, Cranks, Shimano Ultegra
Fork Fork, 2, 0, Fork, Fenix SL Disc, 30T-24T HM Unidirectional carbon
Frame Material Frame Material, 2, 0, Frame Material, Fenix SL Disc, 30T-24T HM Unidirectional carbon
Front Derailleur Front Derailleur, 2, 0, Front Derailleur, Shimano Ultegra
Handlebar Handlebar, 2, 0, Handlebar, 4ZA Stratos E2
Rear Derailleur Rear Derailleur, 2, 0, Rear Derailleur, Shimano Ultegra
Saddle Saddle, 2, 0, Saddle, 4ZA Cirrus Pro, Cr/Ti rails
Seatpost Seatpost, 2, 0, Seatpost, New 4ZA Stratos 27,2x350mm
Shifters Shifters, 2, 0, Shifters, Shimano Ultegra ST-RS685
Stem Stem, 2, 0, Stem, 4ZA Stratos
Weight (kg) Weight (kg), 2, 0, Weight (kg), 8.4
Wheelset Wheelset, 2, 0, Wheelset, DT Swiss R24 Spline
Year Year, 2, 0, Year, 2017
Chainring Size (No of Teeth) Chainring Size (No of Teeth), 2, 0, Chainring Size (No of Teeth), 36 52
Weight (lb) Weight (lb), 2, 0, Weight (lb), 18.69
Chainstays (cm) Chainstays (cm), 2, 0, Chainstays (cm), 41
Seat Tube (cm) Seat Tube (cm), 2, 0, Seat Tube (cm), 54
Standover Height (cm) Standover Height (cm), 2, 0, Standover Height (cm), 82
Top Tube (cm) Top Tube (cm), 2, 0, Top Tube (cm), 54.9
Wheelbase (cm) Wheelbase (cm), 2, 0, Wheelbase (cm), 99.2
Frame size tested Frame size tested, 2, 0, Frame size tested, M