Cervelo S5 Aero Road Bike – Unboxed, Weighed & First Rides

When the Cervelo S5 first stepped on the scene, the numbers looked good but I wasn’t stoked about the looks. Now that’s it’s sitting in our office, I have to admit, my tune’s changed a bit. Perhaps it’s just familiarity, or perhaps it’s seeing all of the other aero road bikes that have popped up lately, but it’s growing on me more and more every day. It doesn’t hurt that it rides pretty well.

When it first arrived, our review model had seen some rough love, so it sat for a week while we waited on missing/broken parts to arrive to make it rideable. Now, two weeks after its rehab, I’ve put about 220 miles on it. Per usual, it’s also been on the scale and photo’d, so click on through to see the details and some first impressions…

CERVELO S5 ACTUAL WEIGHTS

Out of the box, the size 58 Team edition weighs in at 7.02kg (15lbs 7oz).

With Speedplay pedals, a carbon water bottle cage and seat bag with tool, tire lever, tube, CO2 filler & canister, it comes in at a rideable weight of 7.60kg (16lbs 13oz).

CERVELO S5 TEAM FRAME

The S5 comes in two frame options, the regular and the VWD (Vroomen White Design). The regular frame is sold as a regular frameset with their FK26 SL fork (~400g) or the Team frameset with an FK26 UL (~350g) fork. Complete bike builds are available with both setups as well. The base frame is claimed at around 1,300g. The Team frame comes in around 60g lighter.

The VWD uses some of the gram chopping lessons learned developing the Project California R5 and sheds about 270g from the Team S5 frameset, putting it under 1,000g (claimed). The VWD frameset gets the UL fork, too. This version of the frame is only now starting to ship, although it’s been planned and designed since July when the bike was announced.

Cervelo’s service rep David Byers, who provide the weights listed here, is quick to point that they don’t claim exact weights due to the nature of composites. All frames are going to have variances, so these weights are all “ballpark”.

The bike we received to test is the Team frame with UL fork, but the build kit it came with isn’t a standard option. Ours is spec’d with Mavic Cosmic SR carbon aero wheels with Vittoria Rubino Pro tires, SRAM Red group, 3T alloy stem and carbon handlebar. The seatpost is proprietary to the frame (and included with it) and has a Fizik Arione mounted up. Fizik bar tape rounds out the package. The rear wheel is held on with a DT Swiss RWS skewer, but we put our own Mavic skewer on the front because that one was AWOL when the bike arrived.

FRAME & AERO DETAILS

On a group ride, one of my buddies commented “That frame just disappears under you” when he was riding directly behind me. There’s no doubt, it has an incredibly thin frontal profile. The steerer tube is straight 1-1/8″, keeping things very narrow, with only slight bulges at the top and bottom to accommodate the internal headset bearings and keep things stiff.

Up front, the head tube is fairly tall, but the height is exaggerated by the “dropped downtube” design. Cervelo says this minimizes the gap between the fork and front tire and the frame, which reduces turbulence and drag. The fork’s legs are fairly thin and shallow (front to back), but it seems plenty stiff. The crown is very nicely integrated into the frame.

Shift cables hug the stem and drop into the frame directly behind it, running behind the steerer and into the downtube. The rear brake cable runs into the top tube at the front and pops out just before the seatpost.

The seat tube has a curved backside that hugs the profile of rear tire. The gap gets slightly larger as it goes down, and the bike uses traditional dropouts, so there’s no adjusting it.

The downtube is designed to be aero even with water bottles. Since the bike is designed to be the ultimate road bike, it couldn’t make the same usability concessions a TT bike does, which means they new riders want to use water bottles. To address this, the flattened shape at the bottle mounts helps smooth air flow over the bottle better than air running around a tube then hitting another tube (downtube to water bottle). The most aero set up is one bottle mounted on the lower pair of downtube mounts. Next best is the top pair, then a traditional double bottle set up using the mounts on the seat tube, too.

The bottom bracket junction is thick. It’s designed around their BBright asymmetric design, which pushes the bottom bracket shell 11mm further out on the non-drive side. This extra real estate makes the entire section stiffer, and Cervelo maximizes this by making the non-drive chainstay quite a bit thicker than the drive side.

From the front and above, it’s glaringly off center. BBright frames require BBright cranksets, which have 11mm longer spindles than normal and straighter non-drive crank arms. More info on that at BBright.net. Fortunately, SRAM, Campagnolo, Rotor and FSA make compatible cranksets, and Shimano cranks will fit with an adapter.

Before getting the bike in, Cervelo’s PR man Mark Riedy asked probably 20 times “Are you sure you need a 58? That’s a really big bike.” Yes, indeed, the 58 fits my 6’2″ frame really well, but after seeing the original set up, I understand his concern.

The seatpost offers two positions, spaced almost 4cm apart center to center. The bike came in with it in the rear position, giving it an effective top tube of about 620mm. That’s long. Cervelo’s geometry chart, though, is based on the front position, listing the ETT at 581mm, which feels just right after moving the seat to the front clamp. As you can see, there’s plenty of room to slide the saddle forward, which makes the S5 a good all around road bike/race bike for triathletes not wanting to commit to a full on TT/Triathlon bike. And for those between sizes or that just like a more laid back position, that option is there. In the front position, it has the standard 73º seat tube angle. Byer says they don’t claim a second, alternate seat angle, instead saying that the rear position equates to about a 35mm offset post. It feels like more than that.

While the non-drive chain stay is far thicker at the BB, the drive side gets wider as it nears the cassette. Byer says this is for two reasons. First, there are some aero considerations. But the bigger reason is putting as much material as possible to keep things stiff without interfering with the spokes. Since the driveside wheel dish is usually flatter, they can bring the stay in a bit further.

The seatstays jut out to hide the rear brake from the wind. Because of this design, there’s no standard brake bridge for the rear brake to mount to. Instead, it mounts to a small metal insert that’s then bolted to the frame above the brake’s pivot. They use a similar design on their P3 TT bike.

Not shown, the S5 frames are both mechanical and Di2/electronic ready out of the box. Battery hole mounts are located on the bottom of the non-drive chainstay, and there are small holes on the bottom of the bottom bracket for wiring to enter and exit. The rear derailleur cable exit at the back of the stay has a rubber grommet that removes to facilitate wiring, and a small sticker just behind the stem and cable holes is for wires.

FIRST IMPRESSIONS

My first two rides were with the saddle in the rear position. I wasn’t able to get comfortable and didn’t feel very powerful. I typically ride with my saddle more forward anyway.

After fixing that, the bike felt quite good on subsequent rides. Giving the handlebar the shimmy test showed a bit of flex at the top, but it definitely doesn’t translate into sloppy handling. In fact, I can drive this bike hard and fast into corners and it reacts immediately. The head angle on the 58 is 73.5º. That steep angle translates into very quick handling, but it also means the bike reacts to every body movement, particularly if your hands are off the bar. Given that they immediately put this bike under Garmin riders as soon as it was launched (and with great race results, too), there’s no doubt this bike is made with racers in mind, and the handling bears that out.

Interestingly, the bike came with a 50/34 chainring combo, but the gearing feels bigger than the 53/39 I have on my own bike. I have no answer for this yet, and I haven’t been back on my bike since this came in. That’s where the long term testing comes in.

I can say that I was able to hang on the 70 mile Sunday group ride much better than usual. I certainly haven’t been training any more, so I’m inclined to give some credit to the bike.

One of the more interesting things about hopping on the S5 is the way it feels when standing up and cranking. If you’ve ever ridden a triathlon bike, it’s kind of like that. Somehow it just feels like the tubes are tall and ultra stiff, and it’s a bit weird compared to a standard road bike. Not bad, just different, and takes a bit of getting used to.

All that said, I’m really enjoying the S5 and am looking forward to several hundred more miles on it…and hopefully a little side-to-side comparison with the R3/R5, too. Stay tuned…