We got to ride the Cervélo S3 Disc Ultegra Di2 over three days on plenty of varied terrain, and our 58cm test bike weighed in at 8.1kg, which included two bottle cages and pedals in place. The bike came with Enve 3.4 disc brake wheels (Enve carbon rims on Formula disc hubs), a Shimano Ultegra Di2 groupset and the AB04 aero bar.
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Cervélo S3 Disc Ultegra Di2 spec overview
- Weight: 8.1kg (inc. pedals, 2x bottle cages, 58cm frame)
- Frame: Cervélo All-Carbon
- Fork: Cervélo All-Carbon, tapered S3 fork for Disc
- Bottom bracket: FSA PF30
- Handlebar: Cervélo, All-Carbon
- Shifters: Shimano Di2 ST-R785
- Gears: 11-spd Shimano Ultegra Di2 6870
- Brakes: Shimano BR-RS805 hydraulic disc Shimano RT81 160 mm rotors
- Crankset: FSA SLK 52x36
- Cassette: Shimano Ultegra 6800, 11-spd, 11-28t
- Chain: KMC X11EL
- Saddle: Fizik Antares
- Wheels: Enve SES 3.4 for Cervélo
- Tyres: Continental Grand Sport Race 700x23c
Cervélo S3 Disc Ultegra Di2 ride impression
From first swinging a leg over the S3 Disc it's apparent that this is something special. After recently testing (and being similarly impressed) by the R3 Disc, we had high hopes for the aero-optimised disc bike, and for the most part we were impressed.
The S3 Disc feels at once light, rapid and sharp, and it accelerates with impressive ease. The frame and fork feel rock solid in terms of stiffness and encourage you to dig that bit deeper into your reserves to live up to the bike's promise.
On the flat it's impressively rapid, with every pedal stroke rewarded with an addictive need for speed. A small but important factor is the smooth, silent running of the bike. We had no creaks or tweaks even over some pretty rough tarmac — and a section of gravel thanks to an overenthusiastic bit of Garmin routing. The bike was nothing other than silent.
Yes it’s a little less comfortable than the R-Series bike and we were surprised to see 23mm tyres fitted — even if they do come up broader than that on the wide Enve 3.4 rims. Ideally for rough UK roads we’d like to see 25s fitted and there’s room to spare for bigger rubber on the disc frame.
As usual, Shimano Ultegra Di2 performs just as it should; smooth, accurate and chatter-free. The pro-compact FSA 52/36 chainset and 11-28t cassette offer a wide and useable range, and at the top-end the 52/11 gives you plenty of scope to exploit the S3’s speed potential.
The S3 is joyous through a few twisty descents and encourages big lean angles. The hydraulic R785 brakes offer fantastic levels of control and modulation for fast cornering speeds. The swift, sharp steering means pinpoint accuracy, which aids apex hitting, high-speed descending and makes for a truly flickable bike that's great for navigating through the bunch or simply beating traffic.
Light and responsive handling
Climbing can usually be the downfall of an aero focused road bike, but the S3 feels just as capable as its R-series brothers (even if it carries a bit more weight). The stiffness in the chassis, which is bolstered by thru-axles and stiff wheels, makes the S3 feel great when attacking out of the saddle — and the lightness of response makes longer-in-the-saddle climbs rewarding too.
The AB04 aero bar has divided opinion among BikeRadar’s testers, but I am a fan of the compact drop fits — they're within easy reach, meaning you spend more time in them, but the tops may feel too deep for some. The bar also feels amply stiff without being harsh, and the inclusion of the dedicated Barfly mount (available for Garmin, Wahoo and Magellan fittings) solves any GPS mounting woes from when it originally debuted in 2014. It's an expensive upgrade however, available aftermarket at £339 / $400.
The move away from Cervélo fitting ‘training’ spec wheels means the Disc is race-ready out of the box, but the Enve wheels fitted here may have a compromise in the hubs compared to the over-the-counter versions you'd buy from Enve. The Formula hubs are smooth running, with the freehub pick-up nice and quick with it, and although you may be gaining a few grams here the stiff, strong rims are truly impressive. The downside to gaining such an impressive wheelset is a big hike in price — the previous S3 Ultegra Di2 was £4,000 / $5,200 / AU$ 5,400.
At £6,199 / €7,299 / $7,797 / AU$10,320 there's no getting away from the fact that this S3 Disc is a very pricey proposition. It doesn't have many aero-disc rivals though: only a few like Specialized’s Venge ViAS Ultegra Di2 Disc and Storck’s Aernario Pro Disc Ultegra Di2 are similarly priced. Over recent years the least we’d expect at this price point is Dura-Ace level equipment, though the impressive wheels go some way to softening the blow.
Cervélo S3 Disc Ultegra Di2 early verdict
The three days I spent riding the S3 Disc have left me enamoured with it. The light, lively and sharp ride makes it feel like much more of a great all-rounder than an out-and-out aero bike. It’s definitely made my bike wishlist — if only I could get over the price tag.