Cervélo has officially launched the fifth generation of its R5 range, a super lightweight climber’s bike. The changes are centred on weight savings with altered tube shapes and refined carbon wall thicknesses contributing to a significant 705g drop in weight. Both SRAM Red and Shimano Dura-Ace builds of 5.97kg are possible.
There is also a new one-piece bar and stem which Cervélo claims is both two watts more aerodynamic and 150g lighter, while also coming in nine size combinations. New 34 | 37 SL reserve wheels, designed specifically for the R5, have a new finish that is lighter.
Aside from minor changes to the bottom bracket drop to accommodate the 29mm tyres, geometry has been set to match that of the S5 to make swaps easier for Visma-Lease a Bike riders.
There are five specs available, priced from £8,500 to £11,500, including a SRAM Red XPLR AXS single chainring option that Cervélo claims is both the lightest and most aero. Framesets are available for £5,000.
Every detail of the new bike is covered below, or you can skip over to our first ride aboard the R5.
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Cervélo R5: Frameset changes
New R5 tubes (left)
As part of the quest to make the R5 weigh in 250g below the UCI 6.8kg limit, Cervélo has reduced the surface area of the frame by 6.2%, altering the wall thicknesses of the tubes and remodelling the cross-sectional shapes.
That has resulted in a 657g painted frame which is 46g lighter than before. Similarly, the fork has shrunk in surface area by 2.6% and now weighs 302g – a 27g reduction. This is partly due to a new machined routing slot at the rear of the fork steerer for the brake cables which saves 5g against the previously overbuilt drilled hole.
Almost all the tubing on the R5 now has a smaller side-on profile. The fork is not only skinnier but loses its ‘chin’ where it joins the down tube, saving a claimed 8-14g. The head tube is shallower which Cervélo says has resulted in an 8% decrease in stiffness.
At the bottom bracket, material has also been trimmed off in the joins between the thinner chainstays and down tube, but Cervélo claims this lower volume has increased bottom bracket stiffness by 13%.
‘Where the bottom bracket gets a little boxier, that’s where it got tightened up,’ says Clinton Hostetlet, development engineer at Cervélo. ‘What I mean by that is if you compare the old and the new R5, you can see there’s a wall thickness change through there. Our engineers are better able to control wall thickness in that part of the bike to reduce weight without compromising any level of stiffness.’
The already skinny seatstays are now even skinnier, measuring just 10mm x 10mm which is the minimum required by the UCI.
‘The seatstays are so thin they provide bracing rather than support, almost like a guy rope on a tent,’ says Hostetlet. ‘They don’t take a lot of stress but the junctions at each end do.’
And while the R5 wasn’t designed with aerodynamic gains in mind, Cervélo claims it is now two watts faster – mainly due to the new cockpit – at 48kmh averaged across yaw angles.
The frame only comes in black, with either gold or silver lettering.
Cervélo R5: Updated brake scaffolding
Cervélo says it has saved weight at the front brake mount by introducing a direct through bolt mounting, eradicating the aluminium brake plane. This is an 160mm rotor standard. The mountings now also use titanium instead of heavier aluminium.
‘This is possible because of a hollow construction throughout the fork,’ says Hostetlet. ‘We try and avoid aluminium inserts wherever we can because they add weight. It will also help to reduce heat soaking through from the aluminium insert to the fork’s carbon which is better for overall durability.’
Cervélo says the rear brake mounting, which takes a 140mm rotor as standard, has been resculpted and indeed the profile is more slight than on the outgoing R5.
‘We made it as minimal as possible,’ says Hostetlet. ‘We got rid of some bulkier elements that are part of many of our bikes’ rear brakes right now.’
Cervélo R5: Sweat the small parts
Cervélo has also tried to slim down the R5’s proprietary and small parts. The new seat post is said to be 23g lighter thanks to a trimmed down ‘head’ section, a key concern because of its location.
‘There are some places where it’s better to have weight than others – we call this strategic weight,’ says Hostetlet. ‘The lower down on the bike you can locate weight, the better, because of it’s affect on a rider’s centre of gravity.’
Cervélo has updated the alloy rails and designed a new carbon fibre cradle to house the saddle which has saved 27g. The seat post clamp has also been pared back to save 6g.
Not content with the Sram UDH, Cervélo designed its own éUDH which is a gram lighter in the Sram compatible version and 5.8g lighter in the Shimano compatible version.
‘We wanted this bike to be UDH compatible – which it is – but we didn’t really like the way the UDH looked,’ says Hostetlet. ‘It was very bulky and boxy in nature. The one we designed is unique to us, all aluminium, a little more sculpted and visually less impactful as well as, of course, lighter.’
Cross-compatibility is maintained with Sram’s UDH, so if the éUDH breaks for any reason, riders can revert to the original.
Finally, the redesigned compression plug for the steerer is 9.5g lighter and the bearing caps from the Caledonia 5 have been ported over for a nominal weight saving.
Cervélo R5: Component weight savings
Having shed around 300g from the complete frameset and cockpit, Cervélo said it has found the remainder of R5’s weight savings in thurd party componentry.
That includes savings as small as 18g on a specific headset bearing from FSA, 14g on bar end caps, through to a 50g lighter Prologo saddle and wheels from sister brand Reserve that are 60g lighter than before.
‘I pushed Reserve on the rim weight,’ says Hostetlet. ‘Reserve was able to shave weight by changing the finish in the rims – about 30 grams per rim – which brings them to 1,200g for the pair. Reserve is proud of the strength of its rims and impact resistance. This weight change didn’t impact that characteristic. They are structurally the same.’
Overall, Cervélo claims builds of 5.97kg are possible. That runs the 5.9kg Scott Addict RC extremely close. The next closest competitor is the Specialized Aethos at 6.17kg, which, unlike the R5 and the Adddict RC, will not be used in WorldTour races. (Although, strictly speaking, Scott’s sponsored team Q36.5 aren’t a WorldTour team – but we digress.)
Cervélo R5: Geometry
With a view to smoothing bike transitions for riders on its sponsored teams, Cervélo says the geometry of the R5 now matches that of the S5, meaning it now has a 2mm longer reach and a lower 4mm stack for a given size.
‘When you look at the geometry tables, because of the unique proprietary cockpit of the S5, the geometry tables will show a different stack and reach number, but the fit geometry is the same between the two bikes,’ says Hostetlet.
‘In terms of the steering geometry, we dropped the bottom bracket down about two millimetres versus the outgoing R5. That’s basically further optimisation for wide 29c tyres which is what the team runs normally. We spec 26C on the bikes that you’re riding right now for people to walk out of the shop with the lightest package possible.’
The Visma-Lease a Bike team rides Vittoria Corsa Wide Rim 29mm tyres but the Vittoria Corsa Pro Speed TLR G2 are specced here.
Cervélo R5: One-piece cockpit
Cervélo has moved from the two-piece bar and stem of the previous generations of the R5 to a one-piece design that mirrors elements of the S5’s – notwithstanding the hyper aero split stem. The two-degree sweep from the hoods results in a 4cm wider gap between the drops versus the hoods.
The new HB18 weighs 283g (40cmx100mm) which is 134g lighter than the outgoing two-piece setup.
Cervélo says this is largely thanks to the removal of excess materials required to clamp the bar onto the stem, including the insert at the headset where bolts lock the steerer in place, and even a 7g saving on the now lower steerer top cap.
‘We didn’t include an aero drop for the bars,’ says Clinton Hostetlet, development engineer at Cervélo. ‘There is a normal round cross-section in the drops. We took the aero penalty on this area because we just weren’t too concerned about its aerodynamics.’
Dependent on the frame size, dimensions for the five cockpit sizes fitted to the R5 vary from 360x80mm up to 400x120mm. There are also four aftermarket options, for a total of nine different cockpit dimensions.
Cervélo R5: 2025 Cervélo R5 specs and prices
Cervélo will sell the R5 in five full builds as well as frameset-only and in sizes 48, 51, 54, 56, 58 and 61.
All builds get the new one-piece HB18 cockpit and the ultralight Reserve 34|37 SL rims, although lower specs replace DT Swiss’s premium 180 hubs with its 240 hubs.
There’s a 1x spec option, kitted out with SRAM Red XPLR AXS, that Cervélo claims is the lightest weight build.
‘With the Red XPLR you match the top end speed of the mid compact SRAM Red or Force AXS but you beat it by a chunk in the low ranges,’ says Hostetlet. ‘It’s also the lightest spec to build.’
All specs are fitted with a dual-sided power meter, either from SRAM or 4iiii.
Cervélo R5 Red AXS
Groupset: SRAM Red AXS 2x, 48/35t, 10-33t
Power meter: SRAM AXS
Wheels: Reserve 34|37 on DT Swiss 180 hubs
Tyres: Vittoria Corsa Pro Speed TLR G2.0 26mm
Saddle: Prologo Nago R4 Pas Lightweight TiRoX
Price: £11,500 / $14,250 / €12,999
Cervélo R5 Dura-Ace Di2
Groupset: Shimano Dura-Ace, 52/36t, 11-34t
Power meter: 4iiii Precision Pro Gen 3+
Wheels: Reserve 34|37 on DT Swiss 180 hubs
Tyres: Vittoria Corsa Pro Speed TLR G2.0 26mm
Saddle: Prologo Nago R4 Pas Lightweight TiRoX
Price: £11,000 / $14,000 / €12,999
Cervélo R5 Red XPLR AXS 1
Groupset: SRAM Red XPLR AXS 1x, 48t Aero, 10-46t
Power meter: SRAM AXS
Wheels: Reserve 34|37 on DT Swiss 180 hubs
Tyres: Vittoria Corsa Pro Speed TLR G2.0 26mm
Saddle: Prologo Nago R4 Pas Lightweight TiRoX
Price: £11,000 / $14,250 / €12,999
Cervélo R5 Ultegra Di2
Groupset: Shimano Ultegra, 52/36t, 11-34t
Power meter: 4iiii Precision Pro Gen 3+
Wheels: Reserve 34|37 on DT Swiss 240 hubs
Tyres: Vittoria Corsa Pro Speed TLR G2.0 26mm
Saddle: Prologo Nago R4 Pas Lightweight TiRoX
Price: £8,500 / $9,950 / €8,999
Cervélo R5 Force AXS
Groupset: SRAM Force AXS 2x, 48/35t, 10-33t
Power meter: SRAM AXS
Wheels: Reserve 34|37 on DT Swiss 240 hubs
Tyres: Vittoria Corsa Pro Speed TLR G2.0 26mm
Saddle: Prologo Nago R4 Pas Lightweight TiRoX
Price: £8,500 / $9,950 / €8,999
Cervélo R5 Frameset
Price: £5,000 / $6,500 / €5,699
