Aerodynamic handlebars are an easy way to improve your bike’s performance, ergonomics and appearance. There are a lot of aero bars to choose from on the market including integrated one-piece designs that mold the stem into the bars or more conventional two-piece drop bar options. For this review, we’ll be looking at the Bontrager RSL Aero road dropbars which are the bars we’ve personally chosen for our Trek Madone Gen 8. As a part of the Race Shop Limited (RSL) lineup, these are the top handlebars in Trek’s lineup and have a matching $384.99 retail price. The bars are available in four variations from 38-44 cm widths to accommodate different rider preferences. Constructed from OCLV carbon fiber the RSL Aero Road bars are lightweight and strong that are only compatible with electronic groupsets.
The Trek RSL Aero Road bars combine a full OCLV carbon fiber construction with a flared aero profile that’s comfortable in any position
| Rating | 9.5 / 10 |
| Retail Price | $384.99 |
| Measured Weight (in g) | 251 (410/440mm w/ plastic cable routing helpers) |
| Likes | + Lightweight OCLV carbon fiber construction + Tapered aero profile that is comfortable in any position + Clean cable routing and separate bar tap region |
| Dislikes | – Premium price |
| Where to Buy (US) | Trek |
FIT & FINISH
Visually, the Bontrager RSL Aero Road handlebars have a sleek matte finish with internal cable routing and aerodynamic center section. Trek offers the bars in four variations: 350 / 380 mm, 370 / 400 mm, 390 / 420 mm and 410 / 440 mm. The first measurement is the control width which is measured from the top corner to corner, while the drop width is from the bar ends. The handlebars also have a 6 degree flare which means they flare outward to give you a more stable position while riding the drops. Trek has designed the RSL Aero Road bars to have a 124mm drop and a 80 mm reach which would classify them as a shallow or medium drop bar.
The bars have an aero profile that sweeps backward slightly with a smooth transition to the circular center clamp region. There is very little space between the aero transition and the stem which means you cannot run a traditional clamp-on out-front mount. Instead, you’ll need to use something like Trek’s Blendr system which builds the mounts into the stem face instead. Per Trek, the bars are designed for electronic shifters only due to the aggressive curvature of the internal cable routing. The cables enter at the rear of the shifters and exit at the bottom for a sleek and clean appearance. Additionally, there is a dedicated bar tap region with a slightly smaller circumference that accounts for the thickness of the bar tap which ensures you have a smooth transition between the exposed aero center and the bar tap instead of a bulge.
RIDING IMPRESSIONS
We picked up these bars as an upgrade for our recently acquired Trek Madone SL5 Gen 8 which come with basic drop bars. Having reviewed a number of RSL products like the Trek RSL saddle, we’ve become a fan of the design and finish of the products. What attracted us to these bars in particular was the less aggressive aero profile and tapered design. Previous aero bars we’ve used were simply too wide and uncomfortable to hold. Trek has solved that with the thin profile that feels ergonomic while still providing aerodynamic benefits. Installation was straightforward with our Shimano Dura-Ace Di2 shifters using the pre-installed plastic cable guides.
The separate bar tape regions make it easy to align and get perfect symmetry bar tape with both sides as the transition is sharp and clean. Even with the lack of bar tap on the center sections, the handlebars are comfortable and ergonomic as they sweep backwards slightly. On fast descends, the shallow drop and 6 degree flare result in a wide stance that lets you take corners with confidence. While they are pricey, handlebars are a direct contact point with you and the bike so we were happy with the purchase and improved feel and appearance of the bars. Combined with a Blendr stem to mount a GPS computer and front light, bars gave our bike a clean and pro appearance.
THE VERDICT
Overall, we found the Bontrager RSL Aero Road handlebars to be high performance and comfortable handlebars. Trek has designed the RSL Aero Road handlebars with a race fit to optimize ergonomics and aerodynamics while using lightweight OCLV carbon fiber to match other RSL products. We were impressed with the ergonomic feel of the handlebars which have an exposed tapered aero center section that’s perfect for riding upright and separate bar tape region on the drops and bars for more aggressive positions. The 6 degree flare ensures the bars are stable while on the drops while still optimizing aerodynamics when riding on the hoods. For short or long rides, the handlebars felt like a perfect fit for us and far more comfortable than more aggressive aero bars we’ve previously used. The only downside of the bars is the premium price point that is competitive with other high end carbon handlebars. That said, the RSL Aero Road handlebars offer impressive performance and ergonomics.