Ride Quality
Cervelo, like Specialized, are masters of combining stiffness and compliance, and the R5 is a great example. The ride is impressively smooth in both front and rear, with solid compliance that doesn’t sacrifice efficiency. The seatpost does not have much noticeable flex, but narrow, shaped seatstays soak up much of the road chatter—this would be even better with a more compliant wheelset. And the full carbon bar, while a bit narrow, did not seem to transfer much chatter to the hands. As for rider position, the relatively tall head tube allows for a tad more relaxed perch than some Race bikes, which is especially appreciated on long rides and climbs. 

Stiffness-to-Weight/Power Transfer
At just over 14lbs, the Cervelo R5 might be forgiven for sacrificing some efficiency, but no need: The frame handled the most aggressive efforts we had to give with precious little noticeable flex underfoot, and the front end was almost as solid. While beefier frames will fare a little better, the lower weight will counter most or all of that flex. This is mostly thanks to a massive bottom bracket area, head tube junction and downtube (especially near the BB), which also benefits from what must be a very strategic layup, because as we’ve seen in other bikes, size can be misleading here. Pure sprinters will prefer more beefy frames while this bike offers outstanding power transfer for most everyone else. 

Climbing/Efficiency
The only lament while testing the Cervelo R5 was that there weren’t enough hills. Big hills. Steep hills. This bike chews up hills and spits them out, regardless of difficulty. If there’s a pure climber’s bike in the group it’s the R5—but we can’t really call it that because it performs so well in the flats too, especially considering the aero benefits of its head and down tubes. Overall efficiency is quite impressive, and with its relatively comfortable rider position and excellent power transfer, that’s magnified on all but the gnarliest steeps and uphill sprints. The only way to make this a better climber would be to upgrade wheels to lighter set, as perimeter weight has an exponential effect on roll-up and momentum, but this is a very minor detail.  

Descending/Handling
The Cervelo R5 bike handles beautifully overall, with super quick (but not too twitchy) steering and precise lines through turns. There is minor flex up front when the bike is really driven into a downhill turn, or over bumpy sections (we did not notice this at slower speeds in the flats), but it was a nuisance at worst, barely noticeable at best. Most of this was in the wheels and narrow bars, not the fork/head tube. Riders will climb so well uphill that they may not need to take too many risks on the descent anyway—they’ll be far enough ahead not to worry about being passed!

Components, Drivetrain, Shifting and Brakes
Whether or not you like electronic shifting—many riders simply prefer the feel of a mechanical shift, and don’t want to worry about battery or other issues—no one can deny the incredible precision, speed and reliability of Shimano’s Dura Ace Di2 system. The Cervelo R5 features the shifters and derailleurs, paired with Rotor’s impressively light and stiff 3D+ crankset and rings. Shifting is simply effortless, and we noticed no issues with the interface with the Rotor cranks. There’s a wide range of gearing with the sub-compact 52/36T front rings and 11-25 cassette, although on a pure climber like this a 28 would be more appropriate, depending on where you live. Adjustments are super simple, with a few clicks of the lever moving the derailleurs ever-so-slightly one way or the other. Our major complaint about DA Di2 is the considerably higher cost, which we don’t feel is worth the minor weight savings over Ultegra Di2 and/or the mechanical versions, but for those who must have electronic, this is as good as it gets.

Other components are top-end FSA carbon for seatpost and bars, and an ultralight alloy stem. The Fizik saddle with Ti rails is quite comfortable, especially if you don’t prefer a full cutout. 

Wheelset
On a bike as top-end as the Cervelo R5 we feel the HED Ardennes Plus LT wheelset is a major a compromise. While the wheels are an excellent value for an all-around wheelset, they’re simply too heavy and frankly we’d expect carbon rims, and at the very least, straight-pull spokes in the rear hubs. There was some flex at heavy torque, and they were not the smoothest we’ve ridden. The positive here, is that like the bike, these wheels are decent at all types of riding, and are strong enough to handle roads like you’d see in the Spring Classics, after which they’re named. An ultralight set of pure climbing wheels, for instance, would not hold up under sprints or dirt, etc. But there are plenty of higher-end wheelsets that can handle it all.