The Cervelo S5, by a measurable margin. Cycling News's wind tunnel pegged the new S5 as the fastest bike they've ever tested, saving 27.57 watts versus their baseline at 40 km/h with a rider onboard. Per road.cc, a like-for-like Soloist gives up roughly 190 grams of aero drag to the S5 — small but meaningful in racing terms.

At social-ride speeds below 30 km/h the gap shrinks to something you'll never feel.

Reviewer-tested S5 builds at size 56 have come in around 7.17–7.44 kg (Granfondo). The Soloist Ultegra Di2 at size 56 weighed 8.47 kg in road.cc's test, though that's with the heavier alloy cockpit and shallower wheels — frame-only, the Soloist is roughly 250 g heavier than the S5 per Cervélo's own published deltas.

Build choice matters more than frame here: a Soloist Force AXS with carbon bar will close most of the gap.

Less than you'd expect. At size 54 both bikes land within 2 mm of stack (542 vs. 540) and 1 mm of reach (384 vs. 383), with the same 73° head tube angle.

The handling differences are at the edges: the S5 runs 5 mm shorter chainstays (405 vs. 410), 1.7 mm less trail (55.6 vs. 57.3), and a 19 mm shorter wheelbase. That makes the S5 sharper and more eager; the Soloist trades those for predictability — exactly what its R5-derived geometry is designed for.

Both bikes officially clear 34 mm. The S5 ships with 29 mm Vittoria Corsa Pro TLR G2.0 tires on wide-internal Reserve 57|64 rims (where they often measure closer to 31 mm). The Soloist ships with 28 or 29 mm Corsa N.EXT TLR tires depending on build, on slightly narrower Reserve 40-series rims.

Neither is a gravel bike — for chip-seal and worse, look at Cervélo's Caledonia or Áspero.

The Soloist, decisively. It uses a T47 threaded bottom bracket (much more home-mechanic-friendly than press-fit) and a two-piece cockpit — a separate ST36 alloy stem and HB13 carbon bar — meaning you can swap stem length or bar width without re-bleeding hydraulic hoses.

The S5 uses a Cervélo-specific BBright press-fit shell that also houses the Di2 battery, and a one-piece HB19 carbon cockpit. Velo flagged the BBright as a service hassle. That said, Cervélo improved front-end access on the new S5 versus the previous generation.

No. Per Cycling Magazine, Cervélo designed the Soloist as a purpose-built frame, not a detuned S5. Geometry comes from the R5 climbing bike, not the S5. Tube shapes are shallower-section semi-aero. The bottom bracket standard is different (T47 vs. BBright press-fit). The cockpit is two-piece. The stock wheels are shallower.

It's a different bike that happens to share a brand and a 34 mm tire ceiling — closer in spirit to the R5 with aero leanings than to a discounted S5.

No mechanical — every S5 build is electronic. 1x is available, and notably Cervélo positioned the SRAM Red XPLR AXS 1x as the top-tier flagship build on the new S5. Cervélo claims a 2-watt aero saving for 1x, though Bicycling's reviewer found the gear jumps awkward on climbs.

The Soloist offers mechanical 105 at the entry level ($3,900) and a Force AXS 1x build ($7,600) at the top — broader range, more buyer choice.

Both frames carry Cervélo's lifetime frame warranty to the original owner against manufacturing defects. Cervélo also runs a 60-day cockpit-fit-swap policy on the S5's one-piece HB19 — if the as-spec'd bar/stem combo doesn't fit, they'll swap it at no extra charge. That mitigates the usual integrated-cockpit fit risk on the S5.