Ridley Falcn RS Ultegra Di2 review

The Ridley Falcn RS is an all-in-one race bike designed to combine aero bike efficiency with light weight and sharp handling.

In adopting a trend arguably initiated by the Specialized Tarmac SL7, which has recently evolved into the new Tarmac SL8 – with many other bikes from competing brands in between – the Falcn RS has stiff competition.

Here, the standout features are a very aggressive geometry, which is tailor-made for racing, matched to an 825g frame said to be almost as aero-efficient as the Noah Fast Disc.

Although Ridley’s claims aren’t backed up by easily comparable numbers, one thing is certain: the Falcn RS has proven a devilishly fast bike that practically goads you into trying hard all the time.

For some, the ride position may be a little too extreme. But for keen racers and those flexible enough to live with it on and off the race circuit, the Ridley Falcn RS is a serious speed machine.

Ridley Falcn RS Ultegra Di2 frame

The Ridley Falcn RS high-modulus carbon frame looks mean and purposeful, closer to an evolution of the Noah Fast Disc than an aero improvement to the Helium SLX.

In fact, the geometry is said to be an evolution of both (more on that later), but the sweeping curves and deep head tube and seat tube, broad fork crown and legs, plus the compact height of the bike give it the aesthetic of a purpose-built racer.

Ridley doesn’t offer any concrete figures to directly compare the Falcn RS’s outright aero prowess to the competition, or even the Noah Fast Disc (Ridley’s dedicated aero bike).

However, it does claim that the Falcn RS has “similar” aero performance to the Noah Fast Disc, while giving up just 110g in frameset weight to the lithe Helium SLX.

Ridley says the frame weighs just 825g in a size medium, while the fork weighs 380g.

The fork utilises the brand’s F-steerer design, which is essentially (and confusingly) a D-shaped steerer that’s said to provide pinch-free space for internally routed cables and enable the head tube to be sculpted for aerodynamic benefit.

Inside, the upper bearing measures 1-1/8in, while the lower bearing is 1.5in in diameter.

The fork crown flares markedly – Ridley says it creates a diffuser-like effect, where it purposely creates more turbulent airflow behind it.

In theory, this should create more drag in isolation, but the Belgian brand says the down tube (plus the rest of the bike structure that follows it) can pass through this turbulent air more easily, conferring a 10 per cent improvement at 50km/h versus using a standard fork.

At the rear, the seatstays are dropped in a common attempt to improve aero performance further, while curvature of the top tube (in tandem with the low standover height) allows plenty of the D-shape seatpost to be exposed – one of the bike’s few obvious nods to comfort.

The other is the wide tyre clearance. While the Falcn RS is aerodynamically optimised to be run with 28mm-wide tyres, the frame can accommodate up to 700x34c rubber. This matches the Cervelo S5, one of the most progressive dedicated aero road bikes in this area.

The bike uses SRAM’s Universal Derailleur Hanger design, while the front derailleur assembly point can be removed and replaced by a cover for an aerodynamically smooth 1x setup.

Ridley has also included three bidon mounting points on the down tube to allow you some flexibility in where you position your cages.

Ridley Falcn RS Ultegra Di2 geometry

The Ridley Falcn RS’s nominal sizing comes up larger than most comparable bikes.

I’m 188cm/6ft 2in tall, and generally I ride a size 56-58cm bike (roughly equivalent to a size L-XL) depending on the geometry. Here, the medium-sized Falcn RS represents my best ‘race bike’ fit, providing the reach I need while keeping the frame as compact and agile as possible.

Comparing directly, a medium Falcn RS frame has a 397mm reach, while a size 54cm (medium) Specialized Tarmac SL7 has a 387mm reach (398mm in a 56cm).

A Canyon Ultimate CFR in a size medium has a 393mm reach, and 401mm in a size large.

The stack is markedly low too, at 551mm. That’s 14mm lower than a medium Noah Fast Disc, and 6mm lower than a medium Ultimate (26mm lower than a large Ultimate).

That said, it’s broadly comparable to the trend-setting Tarmac SL7 (534mm in a size 54cm, 555mm in a size 56cm).

When you also consider the bike stands visibly lower overall than many of its contemporaries, it looks aggressive.

The head tube angle (73.5 degrees) and seat tube angle (73 degrees) are race-bike steep. Ridley says the 70mm bottom bracket drop (4mm lower-slung than either the Noah Fast Disc or Helium SLX) was settled on to compensate for the use of larger-volume tyres, which will naturally raise the ride height.

407mm-long chainstays across the six-size range (2XS-XL) are claimed to keep reactions sharp, while the compact wheelbase doesn’t stray over 1,000mm until you get to the second largest frame in the range.

Overall, nominal sizing disparity aside, it’s fair to say the geometry is settled in pure race bike territory – certainly towards the more aggressive/pro racer end of the spectrum.

Ridley Falcn RS Ultegra Di2 build

My test bike comes with a Shimano Ultegra Di2 R8100 build.

There’s little deviation from the standard groupset, with Ridley opting to fit a 52/36-tooth crankset and 11-30t cassette.

The bike – under its ‘Prototype’ guise – might have helped Lotto-Dstny rider Victor Campenaerts win the Tour de France’s Super Combativity award this year with his late flurry of attacks, but my setup is far more likely to appeal to prospective customers than the Belgian’s larger (and sometimes leftfield) drivetrain choices.

Ridley says each Falcn RS base specification can be modified to suit your needs using its bike builder programme, from wholesale groupset swaps to single-component changes to suit your needs.

The only tweak on the standard Ultegra build is the use of a KMC X12 chain.

Ridley supplies DT Swiss ARC 1400 carbon wheels, with the 36-tooth 240 EXP ratchet freehub system.

DT Swiss’ 50mm-deep ARC rims have a 20mm inner width and 26.5mm outer width, modern and well-proportioned to support 28c tyres. I had no complaints about their performance overall.

That said, if you want to make more of the Falcn RS’s 34mm tyre clearance, a wider wheelset should make more of the tyre size.

Ridley supplied my test bike with Vittoria Corsa Pro tyres, 28c front and 30c rear, with the 30c rear tyre a deviation from the standard build (Ridley says 28c tyres will be provided front and rear by default).

This didn’t quite confer the 2mm width bump it should on paper (measuring closer to 1mm wider at 75psi), indicating that the wheels could be hampering the tyre’s ability to blow out.

The Falcn RS has a Forza Cirrus Pro carbon integrated cockpit and a Forza Aero D-shaped seatpost. The post’s 6mm setback is shorter than many – often, brands offer a 15-20mm setback post, and sometimes the option of an inline model (Ridley says one is on the way).

I’ll often opt for an inline post where I can, but the 6mm setback was moderate enough that I didn’t need to pull the Selle Italia SLR Boost saddle too far forward for my optimum fit.

The cockpit is available in four sizes, which you can select from using Ridley’s builder programme, but right now you’re locked into a sliding scale of sorts: 90mm long, 380mm wide (centre-to-centre), then 100/400, 110/400 and 120/420mm. Again, Ridley says more options are on the cards in the future.

While these sizes will broadly work for most people, if you do happen to want or need a 120mm-long, 380mm-wide combination (for example), you’re out of luck at the time of launch. Like the seatpost, Ridley says more are in the pipeline.

My test bike weighed 7.4kg, including the integrated computer mount and cages.

The build will set you back £8,599/$12,399/€9,399. Although the US dollar price is punchy, in the UK and EU the price is competitive.

For comparison, the cheapest Canyon Ultimate CFR costs £9,499 (albeit with a Dura-Ace groupset), while the new Specialized S-Works Tarmac SL8 costs £12,000/$14,000/€14,000.

Ridley Falcn RS Ultegra Di2 ride impressions

The Ridley Falcn RS is a very fast race bike, there can be no question.

Although conditions vary, I’ve been able to cover a couple of my test loops notably faster than I have on any bike I’ve reviewed in the past year.

There are two key reasons for this: first, the bike is clearly aerodynamically slippery, and plenty stiff and light to feel efficient when climbing varying degrees.

But second, and most importantly, the aggressive, low-slung position naturally enabled me to hunker down and minimise my own profile to the wind.

Of course, this is fine if (like me) you’re flexible enough to hold such a position, but it’s worth noting from the outset that you should carefully consider whether it will work for you.

If the answer is yes, then the Falcn RS is brilliantly entertaining to ride.

The aggressive position pitches you firmly over the bottom bracket, while I noticed the distinct feeling of being low down and ‘integrated’ into the bike, rather than simply sitting atop it.

The road appears visibly closer to me than on any bike I recall testing, offering a real sense of speed. In combination with the business-like ride position – once I’d acclimated to it – it almost encourages you to try hard all the time.

For racers and those interested in riding quickly everywhere they go, it’s a recipe to produce fast average speeds, and possibly race-winning moves (glossing over the fact that Lotto-Dstny fell short of the top step during the 2023 Tour).

The handling backs this up – it’s sharp and direct, but the steering is remarkably predictable.

Although some might prefer a front end that responds to the lightest touch, I found the steadier nature of the Falcn RS a real confidence booster when cornering hard on descents.

While I’ve noted the DT Swiss ARC wheels aren’t as progressive as some, they offer no shortage of performance – fast, responsive and composed when challenged with pimply tarmac.

The Vittoria Corsa Pro tyres might not be the fastest according to our own rolling resistance testing, but pairing them with the ARC rims brings a very enjoyable and confidence-inspiring ride feel.

There’s no denying that the Falcn RS is a rigid racer, but the choice of a D-shape seatpost over a deeper aero seatpost is a smart one that stops the ride from becoming bone-shaking.

Ridley Falcn RS Ultegra Di2 bottom line

All together, the Ridley Falcn RS is a brilliantly quick road bike with handling that somewhat belies its aggressive geometry.

This makes it easy to ride, very fun and rewarding to ride hard, and not nearly as unforgivingly rigid as you might expect.

If I were to pick a bike for an all-out speed assault on a sportive (or a race), I’d be hard-pressed to look past it and choose something else.

That said, while the handling is easy to get on with, the fundamental ride position is still notably aggressive – it rewards those who can live with it, but will likely punish those who can’t.

With the added non-conformity of the sizing, you’ll need to carefully check geometry charts to ensure you get the right size for you.

That, however, takes nothing away from what is a prodigiously fast and entertaining road bike.