Here’s a riddle for you: How do you choose between two things that are incredibly similar, but completely different. Okay, if that question doesn’t make sense, let me boil it down some more. How do you choose between a Specialized Tarmac and a Specialized Roubaix?
Ask anyone off the street what the difference is between these two bikes and they’ll probably be left scratching their heads. They’re both made by Specialized. They’re both carbon road bikes. And they’re both fast and fun. But there are key differences that make the Tarmac better for some riders, and the Roubaix better for others. We’ll explain what they are so you can decide which bike is better for you.
Tarmac vs. Roubaix: Overview
The Specialized Tarmac and Roubaix are the two most popular road bikes we sell. While they appear similar at first glance, each belongs to a different road bike category. The Tarmac is a “road racing bike” while the Roubaix is an “endurance bike.”
Road racing bikes are designed for, you guessed it, road racing. These are the type of bikes you’ll see pro cyclists ride in big races like the Tour de France. Tarmac prioritizes speed and efficiency, so it’s designed to be stiffer, lighter, and more agile.
[button]Read our Tarmac buyer’s guide[/button]
Endurance bikes emphasize rider comfort. The Roubaix is still fast and efficient, but it’s designed with a more relaxed riding position and compliance-enhancing features that make it better on rough roads and extra-long rides.
[button]Read our Roubaix buyer’s guide[/button]
For this comparison, let's consider three key differences between these two bikes: weight, aerodynamics, and comfort.
Tarmac vs. Roubaix: Weight
Climbers will love the light and stiff Tarmac.
On the scales, the Tarmac is the clear winner. Let’s compare two very similar bikes:
This Tarmac Expert weighs 16 lbs 12 oz.
While this Roubaix Expert weighs 18 lbs 1 oz.
Both bikes are the same year, the same size, and have the same build (Shimano Ultegra Di2, disc brakes, and carbon wheels), but the Roubaix weighs nearly a pound and a half more. That extra weight comes from the Roubaix’s comfort-enhancing features, namely the Future Shock (more on that below). For weight weenies, it’s a significant difference, but you shouldn’t lose sleep over it. The Roubaix is still pretty light for a road bike, and in my opinion, bike weight doesn’t really matter to the average rider. It’s unlikely that you’ll actually notice that extra pound and a half of frame weight while riding.
Bottom line: The feathery Tarmac is the choice for weight weenies, but the Roubaix is no pig.
Tarmac vs. Roubaix: Aerodynamics
The 2020+ Roubaix got extensively reworked in the wind tunnel. Photo: Specialized.
Wind resistance is the biggest force riders fight against in the quest for sheer speed. Unlike weight though, aero is much harder for regular riders to measure and quantify, so we’ll have to trust the manufacturer here.
Specialized claims that the 2020 Roubaix is actually more aerodynamic than the 2018-2021 Tarmac SL6 at all measured yaw angles. The 2020+ Roubaix uses new profiles for the head tube, fork blades, down tube, seat tube, and seatpost, to enhance its aero efficiency.
The revised 2022+ Tarmac SL7, however, beats the Roubaix handily. Specialized claims that the updated frame and cockpit of the Tarmac SL7 make it almost as aerodynamically efficient as the discontinued Venge aero road bike. In the wind tunnel, it’s the clear winner.
What about older models? The 2014-2017 Tarmac SL5 isn’t anywhere near as slippery as the SL6 or SL7, but it does have a Venge-inspired ovalized down tube to help it cut through the wind. For pre-2014 Tarmacs and pre-2020 Roubaix though, it’s a wash, as these bikes don’t use aero tubing. Ultimately, aero isn’t the most important thing for casual riding, but if you want to maximize your speed on flat and rolling roads, it’s worth considering.
Bottom line: 2022+ Tarmac SL7 > 2020+ Roubaix > 2018-2021 Tarmac SL6
Tarmac vs. Roubaix: Comfort
I’m going to start off by saying that both of these bikes will be comfortable enough to satisfy most riders. Current and previous-generation Tarmac models employ dropped seat stays and compliant carbon lay-ups for small bumps and vibrations.
The Future Shock 1.0 (2017-2019 Roubaix) and Future Shock 2.0 (2020+ Roubaix) are visible beneath the stem.
That said, the Roubaix is definitely the more comfortable bike of the two. In the back, Roubaix uses a model-specific seatpost (CG-R on 2013-2019 models, Pavé on 2020+ models) that is designed to flex to absorb harsher impacts. Up front, 2017+ Roubaix uses Future Shock, a lightweight suspension system built into the headset that provides 20mm of travel.
The geometry also makes a big difference. The Roubaix is more relaxed than the Tarmac with a lower bottom bracket, shorter reach, and higher stack. This affords two things: more stability and an upright riding position. The lower bottom bracket increases stability, so the bike is less inclined to dance around, saving you energy. It won’t be as agile as the Tarmac in tight groups and fast corners, but it’s better for daily driving, especially on rough roads. An upright riding position isn’t as good for aerodynamics, but it may reduce strain on key body parts like your back, arms, and hands. Remember, everyone’s physiology is different — your results may vary!
Another major comfort factor is tire size. Wider tires have more air volume and can be run at lower pressures, which enhances comfort. In general, a Roubaix can fit slightly wider tires than a comparable Tarmac:
2020+ Specialized Roubaix
2022+ Specialized Tarmac SL7
2013+ Specialized Roubaix
2018-2021 Specialized Tarmac SL6
2014-2017 Specialized Tarmac SL5
The Roubaix’s combination of Future Shock, the CG-R/Pavé seatpost, relaxed geometry, and wider tires greatly reduces rider fatigue. If you regularly encounter rough or broken pavement, dirt, or gravel on your rides, the Roubaix will be more pleasant to ride. I actually recommend endurance bikes for most recreational riders, because the increased comfort will help them ride faster, longer, and more often.
Bottom line: When it comes to maximizing comfort, the Roubaix can’t be beaten.
If you’re choosing between the Tarmac and the Roubaix, consider what type of rider you are, and where you’ll be using the bike. Here’s how I break it down:
Choose the Specialized Tarmac if…
- You’re a road racer or Strava KOM-hunter seeking a competitive advantage
- Your local roads are smooth and well-maintained
- Weight and stiffness are your top priorities
- You prefer a lower handlebar position
Choose the Specialized Roubaix if…
- You aren’t bothered by a minor weight penalty
- Your local roads are rough, poorly maintained, or sometimes unpaved
- Comfort and compliance are your top priorities
- Due to your physiology, you are comfortable riding a bike with a more upright position
Of course, it’s entirely possible to venture onto rough unpaved roads with the Tarmac, or race fast crit races on the Roubaix. That all depends on the rider. Ultimately, both are great bikes, and you really can’t go wrong with either.
So which would you choose and why? Let me know in the comments!