S5
vsV4Rs
Two flagship race bikes, two opposite priorities.
The S5 is a wind-tunnel-first system bike co-developed with its wheels. The V4Rs is a Pogačar-tuned race weapon that prizes stiffness and descending poise.
S5
- Measurably the fastest — Cycling News' wind tunnel saved 27.57 W versus baseline at 40 km/h with a rider on board.
- Wider tire clearance (34 mm) than the V4Rs, plus 29 mm Vittoria Corsas stock for genuine compliance.
- Same wheels at every price — even the Ultegra Di2 build ships with the flagship Reserve 57|64 wheelset.
- Price floor of $10,100 — no entry into the platform under five figures.
- BBright press-fit bottom bracket houses the Di2 battery; servicing is a hassle.
V4Rs
- Class-leading descender — a slacker head angle and longer trail produce "bags and bags of confidence" on fast, twisty descents (BikeRadar).
- T47 threaded bottom bracket — easy to service and free of the creaking that plagues press-fit systems.
- Genuine entry point — the Force AXS build starts at $7,000, $3,100 below the cheapest S5.
- Narrower 30 mm tire clearance limits compliance on rougher roads.
- No wind-tunnel pedigree to match the S5 — aero is a nice-to-have here, not the headline.
Editor’s analysis
This is the rare matchup where both bikes will let you race the Tour, but only one will let you keep up on Strava without trying.
On paper the Cervélo S5 and Colnago V4Rs occupy the same WorldTour-flagship bracket — Visma–Lease a Bike rides one, UAE Team Emirates rides the other, and both have collected Grand Tour stage wins on the current generation. Spend any time in the geometry tables and the philosophies separate immediately. The S5 is an aero-first system bike that gets co-developed with its wheels and cockpit. The V4Rs is a more traditional race silhouette tuned around the way one specific rider likes to descend.
The Cervélo S5 picks aero and refuses to apologize. Cycling News' wind-tunnel test called it the fastest bike they've ever measured, saving 27.57 watts versus their baseline at 40 km/h with a rider on board. The deep bayonet fork, the new HB19 one-piece cockpit, and the wide-internal Reserve 57|64 wheels all aim at the same target: holding speed effortlessly on the flat. The penalty is a starting price of $10,100 — the cheapest S5 in the lineup is still more than the second-priciest V4Rs build.
The Colnago V4Rs aims at a different ride. The head tube angle is a deliberately slacker 71.5 degrees in size 485 (versus 73 on a 54 S5), the chainstays are 408 mm and constant across sizes, and the trail is long enough that BikeRadar called the descending "unerringly poised" and "in a class of its own." It is, by Colnago's own claims, 4–5% stiffer than the V3Rs at the bottom bracket and explicitly tuned around Tadej Pogačar's input. Climb a long Alpine descent and the V4Rs is the bike you want under you.
Put another way: buy the Cervélo S5 if your terrain is flat, your rides are solo, and you care about the watts you save above 35 km/h. Buy the Colnago V4Rs if your terrain is mountainous, your rides have descents that matter, and you care about how the bike behaves when you're cornering at the limit.
Where the builds differ.
Comparing our editor's-pick builds side-by-side. Winners highlighted row-by-row — lower price and weight, and the better-spec component, each mark a point.
Build variants & pricing
Both platforms top out around $14k. The V4Rs starts $3,100 cheaper and offers a Campagnolo halo build the S5 doesn't.
Prices are current US MSRP. The Cervélo S5 ships with the same Reserve 57|64 wheels and HB19 cockpit at every price point — you're paying for the drivetrain, not the platform. Colnago varies the wheels by build, with the entry Force AXS the only spec without published wheel/cockpit details.
How they fit, how they steer.
Stack and reach land within 3 mm of each other (S5: 542/384, V4Rs: 539/383), but the V4Rs runs a 71.5-degree head angle versus the S5's 73 — that's the visible signature of a long-trail descender against a sharp-turning aero bike.
Which size should I buy?
Size recommendations are based on stack, reach, and effective top tube. The V4Rs's 485 sits between the S5's 51 and 54; both ranges overlap in the middle but the S5 extends further at the small end.
→These are starting points. Flexibility, riding style, and preferred position all shift the answer — if you’re between sizes, a professional fit beats a chart.
What the magazines said.
Published reviews from trusted cycling outlets. Click through for the full write-up.
Which one should you buy?
If you live on flat or rolling roads and ride for speed, get the S5. If you live in the mountains and care how a bike descends, get the V4Rs.
S5
If the bulk of your riding is solo or in small groups on flat or rolling terrain, the S5 is the most measurably fast bike in this conversation. The wind-tunnel gap to anything else in the segment is real, the wide-rim wheel-and-tire system makes it more livable than aero bikes used to be, and the same wheels come on the Ultegra build as the Red one.
V4Rs
If you race on hilly courses, ride mountain passes on the weekend, or just live somewhere with descents that matter, the V4Rs's slacker geometry and stiffer chassis pay off every time the road tilts. It's a more traditional race bike — less integrated, less radical — and it's cheaper to enter the lineup. The badge is a bonus.
Questions buyers actually ask.
Short answers to the things we get emailed about most often.
01Which is faster on flat roads?
The Cervélo S5, and it isn't close on the numbers. Cycling News' wind-tunnel test, with a rider pedaling at 40 km/h, recorded 27.57 watts saved versus their baseline — the largest figure they've ever measured. Cervélo's own claim is 6.3 watts faster than the previous-gen S5 at the same speed.
The V4Rs is no aero slouch (Colnago claims a 27.7-watt saving over the V3Rs at 50 km/h, mostly from the integrated CC.01 cockpit) but it's a race bike with aero details, not a system bike designed in a tunnel.
02Which descends better?
The Colnago V4Rs, by consensus. Reviewers from BikeRadar to Just Ride Bikes single out descending as its standout trait — "unerringly poised," "in a class of its own," "bags and bags of confidence." The reason is geometry: a slacker 71.5-degree head angle in size 485 and a long trail figure (~63 mm with 28 mm tires) produce a strong self-centering effect at speed.
The S5 isn't bad in corners — Bicycling Australia called its descending "sublimely good" — but its 73-degree head angle and 55.6 mm trail bias toward sharp turn-in rather than locked-in stability. On long, fast Alpine descents, the V4Rs is the safer bet.
03What's the maximum tire clearance?
Cervélo S5: 34 mm officially, with 29 mm Vittoria Corsa Pro TLRs as the stock tire on every build. The wide-internal Reserve 57|64 wheels measure those tires closer to 31 mm on-bike. One reviewer was skeptical of the 34 mm claim and called even 32 mm "tiny," so leave headroom if you live in the mud.
Colnago V4Rs: 30 mm officially, with stock 28 mm Pirelli P Zero Race tires. There's room to bump to a 30, but the platform isn't designed for anything wider. Neither bike is a gravel substitute.
04How serviceable are the bottom brackets?
This is one of the clearer wins for Colnago. The V4Rs uses a T47 threaded bottom bracket, widely praised by reviewers (Road.cc, Cyclist Magazine, Just Ride Bikes) as a smart choice — oversized for stiffness, threaded for easy service, and free of the creaks that haunt press-fit shells.
The S5 uses Cervélo's proprietary BBright press-fit standard, and the Di2 battery lives in the downtube directly above it. Multiple reviewers (Velo, Granfondo) call BB and battery service "a hassle" or "difficult" — usually a shop job, not a home one.
05How adjustable are the integrated cockpits?
Both are one-piece carbon units, so neither lets you change bar width or stem length without buying a new bar.
The Cervélo HB19 ships across the entire S5 range and is backward-compatible with older S5 frames. Cervélo offers a 60-day free swap window through dealers if your initial size doesn't work — a meaningful concession.
The Colnago CC.01 has no equivalent swap policy that we're aware of, but it does hide a mini multi-tool inside the steerer for on-the-road adjustments — a small but unusually thoughtful touch.
06Are these realistic for amateur racers?
Yes, with caveats. The S5 rewards anyone who spends time above 35 km/h — the aero gains scale with speed, so the faster you ride, the more bike you're getting. Riders who mostly cruise at 25–30 km/h will pay for performance they won't fully use.
The V4Rs is harder to recommend to riders who aren't actively racing or training. Cycling News explicitly flagged that it "needs to be ridden at pro speeds to be enjoyed," with handling that feels dulled at low pace. BikeRadar called the geometry "too focused for many amateur riders." Buy it if you race; lean toward Colnago's C68 if you don't.
07How heavy are they?
Both land in the same general bracket — neither is at the UCI 6.8 kg limit.
The new Cervélo S5 is 124 g lighter than its predecessor; reviewers measure a complete bike around 7.17–7.44 kg in size 56 depending on build (Granfondo).
The Colnago V4Rs test bikes have come in at roughly 7.15–7.24 kg in flagship trim, with an unpainted size-485 frame at 798 g. For a flagship race bike at this price, several reviewers (Just Ride Bikes, Cycling News) noted you might expect lighter — both bikes are aero-leaning, not pure climbers.
08Is the S5's 1x build worth considering?
Cervélo's Red XPLR AXS 1 build replaces the front derailleur with a single 50T aero chainring and a 13-speed XPLR cassette, claiming about 2 watts of additional aero savings. It's the platform's actual top spec.
Reviewer reception has been mixed. Bicycling's Tara Seplavy missed the "Goldilocks gear" on long climbs — the cog jumps in a 1x wide-range cassette can feel large when you're hunting cadence. If you ride mostly flat to rolling and never quite need the in-between gears, it's a defensible aero gain. If you do real climbing, the 2x Red AXS or Dura-Ace build will feel less compromised.
Similar bikes
If your priorities don’t map cleanly onto either of these, one of these adjacent bikes probably fits better.
Tarmac
The reference all-rounder — the Tarmac SL8 splits the difference between the S5's aero focus and the V4Rs's climbing chops. Lighter than either, with broader build-price coverage from $5k up.
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Dogma F
The other top-tier Italian flagship, with the same WorldTour pedigree as the Colnago and a more distinctive curved-fork silhouette. Pinarello's aero-and-light blend lands closer to the V4Rs in handling than to the S5 in pure speed.
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Soloist
Cervélo's own answer for riders who find the S5 too radical or too expensive. The Soloist carries much of the same aerodynamic DNA with simpler maintenance and a substantially lower entry price.
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