“It’s the best of both worlds.” This is a phrase that many of us interpret as a fancy ­­version of “compromise.” Yet when we started reviewing the Cervelo S5, this is exactly what we were hoping to find—a true best of both worlds scenario. We wanted to find a bike that you could crit on Saturday, and then wake up the next morning and rack in transition. Sure, you might need a few accessories to help with that, like a set of 60mm wheels, aerobars, and rear wing. With this in mind, we set off on our review of the S5. And now here we are three months later ready to report on our findings.

Cervelo S5 Ultegra

When we reached out to Cervelo regarding this review, we told them that we were looking to find a bike that could do everything for the least amount of money possible. In other words, we wanted to find a bike that could meet the needs of a cyclist and triathlete on a budget. To that end, Cervelo sent us their S5 Ultegra. This is the most inexpensive S5 available and has a sticker price of $4500. OK, so we know that’s not exactly chump change, but if this is replacing two bikes, it’s really not such a pricey proposition after all.

The S5 Ultegra comes equipped with Shimano’s new 11 speed Ultegra 6800. This was our first long term review of 6800, and our verdict is “long live 11 speeds.” We have always been fans of the Ultegra groupset – Dura Ace performance for less money and just a little weight penalty on your frame. Being that the majority of our riding was on the flat South Florida landscape, we came to enjoy the closer spacing of the 11 speed system. When shifting, there tended to be much less of a jump in the middle gears compared with our older 10 speed systems.

Our S5 came with a Fulcrum wheelset. However, if you were to purchase this bike today, you would get a set of Mavic Cosmic Elite S. Both are perfectly good wheelsets, but most would likely opt to trade up for something a bit deeper. Similarly, while a fi’zi:k saddle was in the box, our trusty Adamo Podium was the only saddle we ever mounted.

In our First Look we shared Cervelo’s data, which showed that the S5 was as fast as a P4. And after spending three months with the frame, we can tell you that it absolutely feels just as fast. But neverless, we still find the data to be a bit shocking. It says a great deal about a company when they are willing to tell the world that their (at the time) top-of-the-line super time trial bike can be beat by a bike meant to be ridden up the Champs-Élysées.

To make the S5 the speedster that it is, Cervelo employed a number of aero tricks with the frame. First up is the dropped down tube meant to smooth the airflow from the fork to the down tube, filling the turbulent air gap behind the fork crown. The down tube is flared and features two water bottle positions—both of which are both hidden from the wind. By using the lowest position you can save a claimed 14 grams of aero drag. The seat tube wraps around the rear wheel and hides the rear break. All of this adds up to a very fast bike.

For those looking to purchase the bike – we highly recommend either test riding the bike prior to purchase or having the dimensions setup on a bike fit machine. Cervélo claims the S5 is built with the same fit as their R-series. While we haven’t had a chance to validate that claim, we can tell you this is a very long bike – so much so that while two of our editors are usually able to share bikes, only one of them was able to easily fit this bike. The other really needed to size down a frame. This is obviously no fault of Cervélo’s and something a good fitter would have caught for us. But since we attempt to get as many opinions of a bike as possible, it is an issue we can sometimes run into.

Our Version of a Hybrid

We spent our first month with the bike getting to know its road riding characteristics. We wanted to see how it handled climbing, riding in a peloton, and sprinting. The first time we got on the S5 we realized just how fast this bike was. Even with stock wheels our mates on time trial machines had trouble pulling away from us. In group rides we came away feeling just a bit more refreshed than we had on more standard road frames. Needless to say, it was becoming obvious that Cervélo got the aerodynamics right with this bike. On the other hand, we did notice that this was a bike we did not get the most out of when sprinting and hitting the corners hard. We could feel just a bit of flex in the frame that made the S5 feel more like our TT machines and less like some of the dedicated road bikes we have around the office. Therefore we came to think of it more as a grand tourer than crit machine.

After that first month we changed things up a bit, introducing new wheels, two different sets of aerobars, and even some extra hydration options. Knowing this frame was as fast as a P4 gave us the confidence to see what kind of TT machine we could create—and oh boy, create we did.

First up was a set of Mavic CXR 60 Cs. Like our S5, the wheels themselves are a bit of a hybrid. In stock form you have a solid 60mm wheel set with phenomenal braking performance. But add Mavic’s CX01 blades and you have a non UCI legal set of wheels that can play with the best of them. We thought this was perfect for those looking to use a single set of wheels for both road racing and triathlons.

Next up we added a set of clip on aerobars. We tried both Profile Design T3+ Carbon and Bontrager’s Race X Lite clip-ons. We’ll be posting our thoughts on each soon, but for now we can say that both gave us the chance to get into a more aero position on the S5. The dual position seat post allows for moving the seat clamp fore and aft by an impressive 40mm. For us that meant slamming the saddle forward and adjusting the bars accordingly. In many ways this is the downside of attempting to use a road bike with a tri position. By slamming the saddle so far forward you end up being more over the front wheel than on a standard TT bike, which results in a position that, at first, can be a bit disconcerting. We found that we started to regularly adjust the seat post depending on the riding style we planned for that day (not at all that unexpected but still a bit of a hassle when riding regularly).

This is also about the point where we realized that if we really wanted to create the ultimate hybrid, we really needed Di2. With Di2 we could easily mount a second set of shifters on the extensions that could be quickly unplugged for gran fondos and then plugged back in as we racked in transition. The downside with that addition is the price tag—with Di2, the bike is now going to set you back $5,750. And for that price you can get yourself both a dedicated TT machine (P2) and either an S2 or R3 for road duties. But this is where personal preference will come to play. Would you rather have a frame with a great groupset that can do double duty, or choose to have race-specific frames with groupsets you may want to upgrade down the line.

Final Thoughts

When considering a bike throughout a review, the question we come back to most often is whether or not we’d choose the bike as a permanent member of the AeroGeeks stable. Also, would we want to ride it every day? When it comes to the S5, the answer is absolutely yes. We are in constant pursuit of speed, so a road frame that is every bit as aero as a P4 is something we simply wouldn’t pass up. While it is not the nimble road machine that other frames may be, the S5 is a group ride assassin that we can also easily rack in transition on any given Sunday. And for us, that is exactly what we’d want parked in our garage.